Clinicopathological characteristics and therapeutic outcomes in thyrotropin-secreting pituitary adenomas: a single-center study of 90 cases

Medical treatment of functional pituitary adenomas, trials and tribulations

CONTEXT

Functioning pituitary adenomas (FPAs) include most frequently prolactinomas, somatotroph or corticotroph adenomas, while thyrotroph and gonadotroph adenomas are very rare. Despite their benign histological nature (aggressive tumors are rare and malignant ones exceptional), FPAs could cause significant morbidity and increased mortality due to complications associated with hormonal excess syndromes and/or mass effect leading to compression of adjacent structures. This mini review will focus on the increasing role of medical therapy in the multimodal treatment, which also includes transsphenoidal surgery (TSS) and radiotherapy.

EVIDENCE SYNTHESIS

Most patients with prolactinomas are treated only with medications, but surgery could be considered for some patients in a specialized pituitary center, if higher chances of cure. Dopamine agonists, especially cabergoline, are efficient in reducing tumor size and normalizing prolactin. TSS is the first-line treatment for all other FPAs, but most patients require complex adjuvant treatment, including a combination of therapeutic approaches. Medical therapy is the cornerstone of treatment in all patients after unsuccessful surgery or when surgery cannot be offered and includes somatostatin receptor ligands and dopamine agonists (almost all FPAs), growth hormone receptor antagonists (acromegaly), adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers (Cushing's disease). Novel medical treatments, especially for acromegaly and Cushing's disease are under research.

CONCLUSIONS

An enlarged panel of effective drugs available with increased knowledge of predictive factors for response and/or adverse effects will enhance the possibility to offer a more individualized treatment. This would not only improve disease control and prognosis, but also quality of life.

Early identification of postoperative remission for thyrotropin-secreting adenomas

OBJECTIVE

Thyrotropin-secreting adenoma (TSHoma) is a rare type of pituitary adenoma, occurring in one per million people. Little is known about TSHoma. We summarized the demographic, clinical and hormonal characteristics of TSHoma based on a single-centre experience. Moreover, we explored the predictive value of postoperative thyroid function for long-term remission.

DESIGN, PATIENTS AND MEASUREMENTS

We retrospectively analysed 63 patients who were diagnosed as TSHoma and surgically treated at our hospital from January 2015 to June 2021. The preoperative clinical characteristics were analysed and compared between remission and nonremission groups. Thyroid function was measured at 1 day, 1 month, 3 months, 6 months, 12 months and over 12 months after surgery to determine whether they could predict long-term remission.

RESULTS

The male to female ratio for TSHoma was 1.25. The mean age at diagnosis was 45 ± 12 years. Clinical presentation was varied, presenting with hyperthyroidism (68.25%), space-occupying effect (15.87%), amenorrhea (7.14% of female patients) and nonsymptoms (22.22%). 88.14% of patients achieved postoperative endocrinological remission. Larger tumour size and tumour invasion into cavernous sinus and suprasellar with chiasmal compression were strong predictors of lower rates of endocrinological remission. Postoperative thyroid function at 3 months was a viable diagnostic predictor for postoperative remission, especially for FT4 level with a 20.65 pmol/L cutoff.

CONCLUSIONS

Tumour size and extent are major prognostic factors for remission. Postoperative thyroid function at 3 months could be used as a clinical prediction tool for long-term endocrinological remission.

Multi-Dynamic-Multi-Echo-based MRI for the Pre-Surgical Determination of Sellar Tumor Consistency: a Quantitative Approach for Predicting Lesion Resectability

PURPOSE

Pre-surgical information about tumor consistency could facilitate neurosurgical planning. This study used multi-dynamic-multi-echo (MDME)-based relaxometry for the quantitative determination of pituitary tumor consistency, with the aim of predicting lesion resectability.

METHODS

Seventy-two patients with suspected pituitary adenomas, who underwent preoperative 3 T MRI between January 2020 and January 2022, were included in this prospective study. Lesion-specific T1-/T2-relaxation times (T1R/T2R) and proton density (PD) metrics were determined. During surgery, data about tumor resectability were collected. A Receiver Operating Characteristic (ROC) curve analysis was performed to investigate the diagnostic performance (sensitivity/specificity) for discriminating between easy- and hard-to-remove by aspiration (eRAsp and hRAsp) lesions. A Mann-Whitney-U-test was done for group comparison.

RESULTS

A total of 65 participants (mean age, 54 years ± 15, 33 women) were enrolled in the quantitative analysis. Twenty-four lesions were classified as hRAsp, while 41 lesions were assessed as eRAsp. There were significant differences in T1R (hRAsp: 1221.0 ms ± 211.9; eRAsp: 1500.2 ms ± 496.4; p = 0.003) and T2R (hRAsp: 88.8 ms ± 14.5; eRAsp: 137.2 ms ± 166.6; p = 0.03) between both groups. The ROC analysis revealed an area under the curve of 0.72 (95% CI: 0.60-0.85) at p = 0.003 for T1R (cutoff value: 1248 ms; sensitivity/specificity: 78%/58%) and 0.66 (95% CI: 0.53-0.79) at p = 0.03 for T2R (cutoff value: 110 ms; sensitivity/specificity: 39%/96%).

CONCLUSION

MDME-based relaxometry enables a non-invasive, pre-surgical characterization of lesion consistency and, therefore, provides a modality with which to predict tumor resectability.

Clinical Characteristics, Diagnosis, and Treatment of Thyroid Stimulating Hormone-Secreting Pituitary Neuroendocrine Tumor (TSH PitNET): A Single-Center Experience

BACKGRUOUND

Thyroid-stimulating hormone (TSH)-secreting pituitary neuroendocrine tumor (TSH PitNET) is a rare subtype of PitNET. We investigated the comprehensive characteristics and outcomes of TSH PitNET cases from a single medical center. Also, we compared diagnostic methods to determine which showed superior sensitivity.

METHODS

A total of 17 patients diagnosed with TSH PitNET after surgery between 2002 and 2022 in Samsung Medical Center was retrospectively reviewed. Data on comprehensive characteristics and treatment outcomes were collected. The sensitivities of diagnostic methods were compared.

RESULTS

Seven were male (41%), and the median age at diagnosis was 42 years (range, 21 to 65); the median follow-up duration was 37.4 months. The most common (59%) initial presentation was hyperthyroidism-related symptoms. Hormonal co-secretion was present in four (23%) patients. Elevated serum alpha-subunit (α-SU) showed the greatest diagnostic sensitivity (91%), followed by blunted response at thyrotropin-releasing hormone (TRH) stimulation (80%) and elevated sex hormone binding globulin (63%). Fourteen (82%) patients had macroadenoma, and a specimen of one patient with heavy calcification was negative for TSH. Among 15 patients who were followed up for more than 6 months, 10 (67%) achieved hormonal and structural remission within 6 months postoperatively. A case of growth hormone (GH)/TSH/prolactin (PRL) co-secreting mixed gangliocytoma-pituitary adenoma (MGPA) was discovered.

CONCLUSION

The majority of the TSH PitNET cases was macroadenoma, and 23% showed hormone co-secretion. A rare case of GH/TSH/PRL co-secreting MGPA was discovered. Serum α-SU and TRH stimulation tests showed great diagnostic sensitivity. Careful consideration is needed in diagnosing TSH PitNET. Achieving remission requires complete tumor resection. In case of nonremission, radiotherapy or medical therapy can improve the long-term remission rate.

A reference center study in thyrotropin-secreting pituitary adenomas: clinicopathological, therapeutic and long-term follow-up outcomes

PURPOSE

This study aims to analyze the clinicopathological features, diagnostic steps, and therapeutic results of TSHomas and to reveal the effective factors on remission.

METHODS

The clinical, radiological, and pathological features and surgical and endocrinological results of 41 TSHoma cases followed between 2005 and 2022 were retrospectively analyzed. The factors affecting the surgical cure were investigated by comparing the groups with and without remission.

RESULTS

A total of 41 patients (23 male,18 female) were included in the study and the mean age was 42 (31.5-49). Palpitation and headache were the most common complaints. The time from the onset of symptoms to diagnosis was 8 (3-20) months. There were 8 patients with a preoperative clinical and biochemical diagnosis of TSH + GH co-secretion. In the TRH stimulation test, a blunted TSH response was obtained in 18 patients (90.0%). Complete suppression could not be obtained in any of the patients who underwent the T3 suppression test. The median maximum tumor diameter was 19.0 mm (6.8-41). There was microadenoma in 4 (9.8%) patients and macroadenoma in 37 patients (92.8%). Remission was achieved in 31 (75.6%) of 40 patients who underwent endoscopic transsphenoidal surgery (eTSS). The Ki-67 labeling index was 2% (1.00-4.00) in the entire patient group. Preoperative use of antithyroid drugs appears to be significantly associated with surgical cure.

CONCLUSION

Diagnosis of TSHoma is still full of challenges and dynamic tests remain important. Recognition and good management of inappropriate TSH secretion states affect subsequent surgical outcomes.

Differences in invasiveness and recurrence rate among nonfunctioning pituitary neuroendocrine tumors depending on tumor subtype

PURPOSE

To clarify the invasiveness to surrounding structures and recurrence rate of each subtype of nonfunctioning pituitary neuroendocrine tumor (Pit-NETs) according to the WHO 2022 classification.

METHODS

This retrospective study utilized data from 292 patients with nonfunctioning Pit-NETs treated with initial transsphenoidal surgery. Recurrence was evaluated on 113 patients who were available for a magnetic resonance imaging follow-up ≥ 60 months. All tumors were assessed by immunohistochemical staining for Pit-1, T-PIT, and GATA3. Invasiveness to surrounding structures was evaluated based on intraoperative findings.

RESULTS

Cavernous sinus invasion was found in 47.5% of null cell tumors, 50.0% of Pit-1 lineage tumors, 31.8% of corticotroph tumors, and 18.3% of gonadotroph tumors. Dura mater defects in the floor of sellar turcica, indicating dural invasion, were found in 44.3% of null cell tumors, 36.4% of corticotroph tumors, 16.7% of Pit-1 lineage tumors, and 17.3% of gonadotroph tumors. In logistic regression analysis, Pit-1 (OR 5.90, 95% CI 1.71-20.4, P = 0.0050) and null tumors (OR 4.14, 95% CI 1.86-9.23, P = 0.0005) were associated with cavernous sinus invasion. Recurrence was found in 8 (4.9%) patients, but without significant differences between tumor subtypes. The presence of cavernous sinus invasion was correlated with recurrence (HR = 1.95, 95% CI 1.10-3.46, P = 0.0227).

CONCLUSION

Among nonfunctioning Pit-NETs, Pit-1 lineage tumors tend to invade the cavernous sinus, corticotroph tumors may produce dura mater defects, and null cell tumors tend to cause both. Pit-NETs with cavernous sinus invasion require a careful attention to recurrence.

[Thyrotropin-secreting pituitary adenomas: clinical features and results of treatment in 45 patients]

BACKGROUND

Thyrotropin-secreting pituitary adenomas (TSH-PA) are a rare cause of thyrotoxicosis and account for 0.5-2% of all pituitary adenomas. Taking into account the rarity of the disease, it is extremely important to analyze each case of TSH-PA.

AIM

To analyze the clinical characteristics and treatment outcomes of patients with TSH-PA, as well as to determine preoperative and early postoperative factors that predict long-term remission.

MATERIALS AND METHODS

In a single-center retrospective study we analyzed clinical signs, laboratory and instrumental studies, as well as the treatment outcomes of patients with TSH-PA from 2010 to 2023. Preoperative factors, as well as TSH level measured on day 3 postoperatively, were evaluated for their ability to predict long-term remission when comparing groups of patients with and without remission.

RESULTS

The study included 45 patients with TSH-PA (14 men, 31 women), with a median age of 45 years [30; 57]. The most common clinical manifestations of TSH-PA were: cardiac arrhythmia in 37 (82.2%) patients, thyroid pathology in 27 (60%), neurological disorders in 24 (53.35%). Most PAs were macroadenomas (n=35, 77.8%). Preoperatively, 28 (77.8%) patients received somatostatin analogs, and 20 (71.4%) patients were euthyroid at the time of surgery. Surgical treatment was performed in 36 (80%) patients, postoperative remission was achieved in 31 cases (86.1%). Administration of somatostatin analogues to patients with no remission/relapse after surgery lead to the remission in 100% of cases (4/4). A 1 mm increase in PA size raised the odds of recurrence/no remission by 1.15-fold,and PA invasion during surgery - by  5.129 fold. A TSH level on day 3 postoperatively above 0.391 mIU/L (AUC, 0.952; 95% CI 0.873-1.000; standard error 0.04; p<0.001) identifies patients with relapse/absence of remission after surgical treatment (sensitivity = 100%, specificity = 88.9%).

CONCLUSION

The TSH-PA in the structure of PAs is extremely rare, and as a result, most of them are misdiagnosed and detected already at the stage of macroadenoma. The most effective method of treatment is transnasal transsphenoidal adenomectomy. Somatostatin analogues can be used as second-line therapy if surgical treatment is ineffective. We have proposed a possible model for postoperative TSH levels (>0.391 mU/l) to predict recurrence of TSH-PA, which requires validation on an expanded number of cases.

Clinical features and therapeutic outcomes of GH/TSH cosecreting pituitary adenomas: experience of a single pituitary center

Background

Growth hormone (GH)/thyroid stimulating hormone (TSH) cosecreting pituitary adenoma (PA) is an exceedingly rare kind of bihormonal pituitary neuroendocrine tumors (PitNETs). Its clinical characteristics have rarely been reported.

Objectives

This study aimed to summarize the clinical characteristics and experience of diagnosis and treatment among patients with mixed GH/TSH PAs from a single center.

Methods

We retrospectively reviewed GH/TSH cosecreting PAs from 2063 patients diagnosed with GH-secreting PAs admitted to Peking Union Medical College Hospital between January 1st, 2010, and August 30th, 2022, to investigate the clinical characteristics, hormone detection, imaging findings, treatment patterns and outcomes of follow-up. We further compared these mixed adenomas with age- and sex-matched cases of GH mono-secreting PAs (GHPAs). The data of the included subjects were collected using electronic records from the hospital's information system.

Results

Based on the inclusion and exclusion criteria, 21 GH/TSH cosecreting PAs were included. The average age of symptom onset was 41.6 ± 14.9 years old, and delayed diagnosis occurred in 57.1% (12/21) of patients. Thyrotoxicosis was the most common complaint (10/21, 47.6%). The median inhibition rates of GH and TSH in octreotide suppression tests were 79.1% [68.8%, 82.0%] and 94.7% [88.2%, 97.0%], respectively. All these mixed PAs were macroadenomas, and 23.8% (5/21) of them were giant adenomas. Comprehensive treatment strategies comprised of two or more therapy methods were applied in 66.7% (14/21) of patients. Complete remission of both GH and TSH was accomplished in one-third of cases. In the comparison with the matched GHPA subjects, the mixed GH/TSH group presented with a higher maximum diameter of the tumor (24.0 [15.0, 36.0] mm vs. 14.7 [10.8, 23.0] mm, P = 0.005), a greater incidence of cavernous sinus invasion (57.1% vs. 23.8%, P = 0.009) and a greater difficulty of long-term remission (28.6% vs. 71.4%, P <0.001). In addition, higher occurrence rates of arrhythmia (28.6% vs. 2.4%, P = 0.004), heart enlargement (33.3% vs. 4.8%, P = 0.005) and osteopenia/osteoporosis (33.3% vs. 2.4%, P = 0.001) were observed in the mixed PA group.

Conclusion

There are great challenges in the treatment and management of GH/TSH cosecreting PA. Early diagnosis, multidisciplinary therapy and careful follow-up are required to improve the prognosis of this bihormonal PA.

Refractory Pit1 plurihormonal tumours and thyrotroph adenomas

Pit-1 tumours are derived from neoplastic cells of either somatotroph, lactotroph or thyrotroph cell lineages, but there are also distinct mixed tumours and plurihormonal tumours within this category as described within the 2022 edition of the WHO classification of pituitary tumours. Plurihormonal tumours and thyrotroph adenomas are transcriptionally similar and grouped together to discuss in this review, although it is clear an immature type of plurihormonal tumour exists which are more commonly associated with refractory disease. Management of residual or recurrent disease should follow that of other aggressive pituitary tumours, although a trial of somatostatin analogue therapy is certainly warranted before considering temozolomide therapy.

Thyrotropin-secreting tumor "TSH-PitNET": From diagnosis to treatment

Thyrotropic adenomas (TSH-PitNET) are the rarest pituitary tumours. Most TSH-PitNETs are secreting adenoma, with a biological picture of inappropriate TSH secretion (moderately elevated TSH, elevated FT3 and FT4). Patients present most often clinical hyperthyroidism, but with more moderate symptoms than in peripheral hyperthyroidism. Biological diagnosis is not always easy. The main differential diagnoses are interfering antibody assay interactions, dysalbuminemia and thyroid hormone resistance syndrome. Misdiagnosis is common. However, the diagnosis is easier when macroadenomas are involved (80% of cases), with symptoms of optic chiasm compression, headache and signs of hypopituitarism. Treatment is initially based on surgery. In case of failure, somatostatin analogues are very effective in controlling tumor volume and secretion, although there is a risk of thyroid insufficiency, which is usually transient.

Challenges in the Management of a 7-Year-Old Child with Thyrotropin-Secreting Pituitary Adenoma and the Review of the Literature

INTRODUCTION

Thyrotropin-producing pituitary adenoma (TSHoma) is a very rare disease, representing less than 1% of the pituitary tumours and presenting with elevated thyroid hormones and normal/high TSH concentrations.

CASE PRESENTATION

A 7-year-old boy with nervousness was referred by his psychiatrist for elevated free T4, T3, and TSH levels. Initial evaluation revealed an elevated α-subunit. Pituitary magnetic resonance imaging (MRI) demonstrated a macroadenoma. The patient underwent a trans-sphenoidal tumour resection (TSS) which showed positive immunohistochemical staining for TSH, growth hormone, and prolactin in tumoral tissue. Euthyroidism was achieved for 1 year after TSS, then recurrence of tumour with elevated TSH and thyroid hormone levels necessitated a re-operation with TSS followed by gamma-knife radiosurgery. The euthyroid state was achieved and lasted for 2.5 years this time, but due to the recurrence, medical treatment had been commenced with cabergoline and octreotide. Euthyroidism was maintained for the last 4 years on monthly octreotide treatment. A repeat MRI demonstrated no pituitary mass, but a mass in the sphenoidal sinus had been detected. Removal of this mass by surgery did not achieve euthyroidism. 68Ga-DOTA-TATE positron emission tomography/computed tomography showed residual tissue extending from the pituitary region to the sphenoid sinus. The patient's bone age was advanced by 2 years at diagnosis which became 4 years in 1 year after the diagnosis and remained so throughout follow-up, leading to a final height of -3.3 SDS below his target height at the age of 16 years.

CONCLUSION

The diagnosis, treatment, and follow-up of TSHomas are challenging, and short stature due to accelerated bone maturation is a complication of paediatric TSHomas.

Effects of Anterior Pituitary Adenomas' Hormones on Glucose Metabolism and Its Clinical Implications

Pituitary adenomas have recently become more common and their incidence is increasing yearly. Functional pituitary tumors commonly secrete prolactin, growth hormones, and adrenocorticotropic hormones, which cause diseases such as prolactinoma, acromegaly, and Cushing's disease, but rarely secrete luteinizing, follicle-stimulating, thyroid-stimulating, and melanocyte-stimulating hormones. In addition to the typical clinical manifestations of functional pituitary tumors caused by excessive hormone levels, some pituitary tumors are also accompanied by abnormal glucose metabolism. The effects of these seven hormones on glucose metabolism are important for the treatment of diabetes secondary to pituitary tumors. This review focuses on the effects of hormones on glucose metabolism, providing important clues for the diagnosis and treatment of related diseases.

Effect of pituitary adenoma consistency on surgical outcomes in patients undergoing endonasal endoscopic transsphenoidal surgery

BACKGROUND

Most pituitary adenomas (PAs) are considered to have a soft tumor consistency. However, there is a non-negligible percentage (5-13%) of tumors presenting or exhibiting a fibrous consistency that would entail a more difficult and complicated surgical excision with higher surgical morbidity and mortality rates.

PURPOSE

To analyze the clinical consequences of PA tumor consistency on the surgical outcomes in patients undergoing endonasal endoscopic transsphenoidal (EET) pituitary surgery.

METHODS

An ambispective study of patients with PAs operated on through an EET approach in two Spanish tertiary hospitals over the last 12 years. A total of 226 consecutive interventions were carried out in the Neurosurgery Departments of the Hospital Universitario Ramón y Cajal (HURC) and the Hospital Universitario Puerta del Sur by the same neurosurgeon. PAs were grouped into soft (n = 150) and fibrous (n = 76). All patients underwent hormonal and magnetic resonance imaging (MRI) studies before and after surgery. In addition, neurosurgical complications were recorded in each patient.

RESULTS

Fibrous adenomas were independently associated with lower resection rates compared to soft adenomas (fibrous gross total resection [GTR] rate 48.7% vs. 76.3%, p &lt; 0.001), even in those adenomas without invasion of the cavernous sinus (Knosp grades 0, I, and II). There were more intraoperative cerebrospinal fluid (CSF) leaks in patients with fibrous PAs. Moreover, fibrous PAs showed higher rates of postoperative hypopituitarism, permanent diabetes insipidus (DI) and postoperative treatments (hormonal treatment and radiotherapy). The excision of a fibrous PA required a longer surgical time (22.5 min more than soft PAs, p = 0.014), regardless of other factors.

CONCLUSION

The consistency of the PAs significantly conditions both the results of surgery (lower resections rates), complications (higher incidence of postoperative hypopituitarism, permanent DI), and the prognosis (higher incidence of postoperative treatments) of the patient undergoing EET.

Resection of the Cavernous Sinus Medial Wall Improves Remission Rate in Functioning Pituitary Tumors: Retrospective Analysis of 248 Consecutive Cases

BACKGROUND

The purpose of transsphenoidal surgery (TSS) for a functioning pituitary tumor (FPT) is to achieve endocrinological remission. The biggest challenge is aggressive tumor resection invading the cavernous sinus (CS).

OBJECTIVE

To evaluate the effects of the medial wall of CS (MWCS) resection during FPT surgery.

METHODS

Consecutive FPTs were reviewed for CS invasion (CSI) between April 2018 and December 2021. We operated on more than 250 FPTs, including 134 somatotroph tumors, 70 corticotroph tumors, 35 lactotroph tumors, and 9 thyrotroph tumors.

RESULTS

The patients were classified into 3 groups based on the relationship between the tumor and the CS: group A (no clear wall invasion), in which MWCS was not removed because of no tumorous direct contact with MWCS (N = 92) and group B (possible wall invasion), where MWCS was removed because we were not confident of MWCS invasion (N = 102). Among these 102 patients, histological tumor invasion was confirmed in 45 of 79 patients (57%) for whom histology findings were available. Tumors invading the CS clearly during surgery were classified into the "clear CS invasion" (group C: N = 55) group. The overall complete remission rate in group B was 94%, which was as high as that in group A (87%). Moreover, we clarified that microscopic invasion of MWCS could not always be predicted from Knosp grading.

CONCLUSION

MWCS invasion occurred in 57% of cases confirmed histologically where it was unclear during surgery, and its resection can improve the overall complete remission rate in FPT cases.

Recent advancements in the molecular biology of pituitary adenomas

INTRODUCTION

Pituitary adenomas are a common and diverse group of intracranial tumors arising from the anterior pituitary that are usually slow-growing and benign, but still pose a significant healthcare burden to patients. Additionally, they are increasing in both incidence and prevalence, leading to a need for better understanding of molecular changes in the development of these tumors.

AREAS COVERED

A PubMed literature search was conducted using the terms 'pituitary adenoma' in combination with keywords related to secretory subtype: lactotroph, somatotroph, corticotroph, gonadotroph and null cell, in addition to their transcription factor expression: PIT1, TPIT, and SF-1. Articles resulting from this search were analyzed, as well as relevant articles cited as their references. In this review, we highlight recent advances in the genetic and epigenetic characterization of individual pituitary adenoma subtypes and the effect it may have on guiding future clinical treatment of these tumors.

EXPERT OPINION

Understanding the molecular biology of pituitary adenomas is a fundamental step toward advancing the treatment of these tumors. Yet crucial knowledge gaps exist in our understanding of the underlying molecular biology of pituitary adenomas which can potentially be addressed by turning to differentially activated molecular pathways in tumor relative to normal gland.

Modified Shoelace Dural Closure with Collagen Matrix in Extended Transsphenoidal Surgery

Extended endonasal transsphenoidal surgery (eTSS) offers a wide surgical field for various parasellar lesions; however, intraoperative high-flow cerebrospinal fluid (CSF) leakage is inevitable. Therefore, secure sellar reconstruction methods are essential to prevent postoperative CSF leakage. Although collagen matrix has been applied for dural reconstruction in neurosurgery, its suitability for application in extended eTSS remains unclear. Eighteen patients underwent modified shoelace dural closure using collagen matrix after lesionectomy via extended eTSS. In this technique, a collagen matrix, which was placed subdurally (inlay graft), was continuously sutured with both open dural edges like a shoelace. Then, another collagen matrix was placed epidurally (onlay graft), and rigid reconstruction was performed using the septal bone and a resorbable fixation mesh. Postoperative CSF leakage did not occur in 17 patients but did occur in 1 patient with tuberculum sellae meningioma. In this case, the CSF leakage point was detected just around the area between the coagulated dura and the adjacent collagen matrix. The collagen matrix harvested from this area was pathologically examined; neovascularization and fibroblastic infiltration into the collagen matrix were not detected. On the other hand, neovascularization and fibroblast infiltration into the collagen matrix were apparent on the surface of the collagen matrix harvested from the non-CSF leakage area. Our novel dural closure technique using collagen matrix could be an effective option for sellar reconstruction in extended eTSS; however, it should be applied in patients in whom normal dural edges are preserved.

[TSH-рroducing pituitary microadenoma: diagnostic problems in the debut of the disease]

Tumors of the pituitary gland producing thyrotropin hormone (TSH) are rare and account for about 1-3% of all pituitary adenomas, most frequently occurring in persons of young and working age. This article presents a clinical case of thyrotropinoma in a 44-year-old woman, which was diagnosed 6 years after her initial visit to an endocrinologist. At the debut of the disease, thyrotropinoma manifested as an isolated elevation of TSH, with normal levels of free T4 and free T3. The patient was constantly taking β-blockers due to her disturbing tachycardia. She was diagnosed with subclinical hypothyroidism, for which she was periodically observed, controlling her TSH level and taking levothyroxine drugs in a dose of up to 175 mcg, which was accompanied by elevated TSH levels. After 6 years, there was an increase in free T3 and free T4 in addition to TSH. Magnetic resonance imaging with intravenous contrast enhancement revealed a pituitary microadenoma 4 mm in size, and laboratory examination of all tropic hormones revealed an isolated increase in TSH. Transsphenoidal adenomectomy was performed at the diagnosis of TSH-producing pituitary adenoma. During the three-year postoperative follow-up there was no adenoma recurrence, secondary hypothyroidism developed, the patient currently takes levothyroxine 75 mcg per day continuously.

Clinical outcomes of 34 patients with resistance to thyroid hormone beta: a twenty-year experience in Japan

Resistance to thyroid hormone beta (RTHβ) caused by germline mutations in genes encoding thyroid hormone receptor beta (TRβ) is a rare disorder. Little information is available regarding the clinical experience of this syndrome in Japan. We retrospectively reviewed the records of 34 patients with RTHβ (21 adult females and 13 adult males) with positive TRβ mutations identified at our division between 2000 and 2020. Of the 24 patients with available clinical history, 10 (41.7%) received inappropriate treatments such as antithyroid drugs, thyroidectomy, or radioactive iodine. Diagnostic delay and inappropriate management of RTHβ are still present in Japan. Every patient except one demonstrated thyroid hormone profiles indicative of syndrome of inappropriate secretion of thyrotropin (SITSH), characterized by a hormonal profile of hyperthyroxinemia with a non-suppressed TSH concentration. Since the most common forms of hyperthyroidism including Graves' disease feature elevated thyroid hormone levels with suppressed TSH concentrations, early diagnosis of SITSH is critical for preventing inappropriate management. One patient positive for anti-thyroglobulin antibody (Tg-Ab) and anti-thyroperoxidase antibody (TPO-Ab) showed remarkably elevated TSH (>200 μIU/mL) despite thyroid hormone concentrations within the reference ranges. At least one thyroid autoantibody (Tg-Ab, TPO-Ab, or thyrotropin receptor antibodies) was identified in 37.9% (11/29) of the patients tested. One patient developed overt Graves' disease nine years after RTHβ diagnosis. These findings suggest that RTHβ is frequently comorbid with additional autoimmune thyroid disorders. Further research is required to identify the most appropriate treatments for RTHβ patients who develop a second thyroid disorder.

Radiological Knosp, Revised-Knosp, and Hardy–Wilson Classifications for the Prediction of Surgical Outcomes in the Endoscopic Endonasal Surgery of Pituitary Adenomas: Study of 228 Cases

Purpose

To evaluate which radiological classification, Knosp, revised-Knosp, or Hardy–Wilson classification, is better for the prediction of surgical outcomes in the endoscopic endonasal transsphenoidal (EET) surgery of pituitary adenomas (PAs).

Methods

This is a retrospective study of patients with PAs who underwent EET PA resection for the first time between January 2009 and December 2020. Radiological cavernous sinus invasiveness was defined as a Knosp or revised-Knosp grade >2 or a grade E in the Hardy–Wilson classification.

Results

A total of 228 patients with PAs were included. Cavernous sinus invasion was evident in 35.1% and suprasellar extension was evident in 74.6%. Overall, surgical cure was achieved in 64.3% of patients. Surgical cure was lower in invasive PAs than in non-invasive PAs (28.8% vs. 83.1%, p < 0.0001), and the risk of major complications was higher (13.8% vs. 3.4%, p = 0.003). The rate of surgical cure decreased as the grade of Knosp increased (p < 0.001), whereas the risk of complications increased (p < 0.001). Patients with Knosp 3B PAs tended to achieve surgical cure less commonly than Knosp 3A PAs (30.0% vs. 56.0%, p = 0.164). Similar results were observed based on the invasion and extension of Hardy–Wilson classification (stage A–C 83.1% vs. E 28.8% p < 0.0001, grade 0–II 81.1% vs. III–IV 59.7% p = 0.008). The Knosp classification offered the greatest diagnostic accuracy for the prediction of surgical cure (AUC 0.820), whereas the invasion Hardy–Wilson classification lacked utility for this purpose (AUC 0.654).

Conclusion

The Knosp classifications offer a good orientation for the estimation of surgical cure and the risk of complications in patients with PAs submitted to EET surgery. However, the invasion Hardy–Wilson scale lacks utility for this purpose.

Surgical Experience of Transcranial Approaches to Large-to-Giant Pituitary Adenomas in Knosp Grade 4

Pituitary adenomas in Knosp grade 4 are difficult to resect completely and are generally involved in poor prognosis, because of the close relationship between the tumor and internal carotid. In this study, the authors retrospectively reviewed the outcome of different transcranial approaches in the management of large-to-giant pituitary adenomas in Knosp grade 4. A total of 42 patients with large-to-giant pituitary adenomas in Knosp grade 4, who underwent craniotomy in the Pituitary Disease Subdivision, Department of Neurosurgery, Beijing Tiantan Hospital, between March 2012 and March 2015 were included in this study. Clinical characteristics, surgical methods, complications, and outcomes were evaluated. The median age was 45 years (range, 19-73 years old), and 42.9% of the enrolled cases were men. The mean tumor diameter was 43.6 mm, and the mean volume was 30.9 cm³. 26 patients underwent the frontolateral approach, while 16 cases accepted the frontotemporal approach. Gross total resection was achieved in 11 patients (26.2%), near total in 26 (61.9%), and subtotal in 5 (11.9%). The adenomas were larger, and the distance of the tumor extending to the lateral skull base was also further in the frontotemporal approach cases. The surgical time was shorter, and the bleeding volume was less in the frontolateral approach cases. Subsellar extension was associated with incomplete resection in pituitary macroadenomas of Knosp grade 4. The craniotomy is still an effective treatment for pituitary macroadenomas in Knosp grade 4.

A rare pituitary tumor associated with hyperthyroidism and acromegaly

BACKGROUND

Mixed pituitary TSH/GH adenomas are rare adenomas associated with acromegaly and/or thyrotoxicosis, with or without varying degrees of goiter. In this report, we show a case of pituitary adenoma producing both GH and TSH simultaneously.

CASE PRESENTATION

A 27-year-old man was diagnosed with pituitary adenoma based on various symptoms and clinical findings. For further examination and treatment, he was hospitalized in our institution. It was likely that this subject had pituitary adenoma producing both GH and TSH. In brain magnetic resonance imaging, there was a giant tumor in the sellar region. After the diagnosis of mixed pituitary TSH/GH adenoma, he was treated with octreotide, then underwent tumor resection, and then received hydrocortisone acetate and levothyroxine sodium. After then, GH and IGF-1 levels were suppressed and thyroid function was normalized. Postoperative immunohistochemistry reports showed GH (+) but TSH (-), which may be insensitive to the antibody used to detect TSH or combined with other factors.

CONCLUSIONS

The diagnosis of mixed pituitary TSH/GH adenoma must be combined with clinical manifestations, immunohistochemical staining and relevant hormone levels, and genetic testing if necessary for comprehensive judgment. For patients with large adenomas, it is recommended to use somatostatin analogs to restore TH levels and control the excessive secretion of GH levels before surgery.

Thyrotropin-secreting pituitary adenomas induce left atrial enlargement with subclinical atrial fibrillation: an echocardiographic study

PURPOSE

Thyrotropin-secreting pituitary adenoma (TSHoma) is rare but occasionally causes cardiovascular complications such as atrial fibrillation (AF) due to hyperthyroidism. Graves' disease (GD) is a common hyperthyroid condition often associated with subclinical AF. Some reports have shown echocardiographic changes in patients with GD. We aimed to evaluate the preoperative cardiac function in patients with TSHomas and compared the results among patients with TSHomas and GD and control subjects.

METHODS

Patients with TSHomas (n = 6) and GD (n = 20) were compared with control subjects with normal cardiac function (n = 20) based on echocardiographic findings. The average age, sex, and proportions of patients with a history of diabetes mellitus and hypertension were equal in each group, and the AF prevalence was matched in patients with TSHomas and GD. The values of left ventricular end-diastolic diameter (LVEDd), left ventricular end-systolic diameter (LVEDs), left ventricular ejection fraction (LVEF), and left atrial diameter (LAD) were used to assess cardiac function.

RESULTS

In echocardiography, LAD showed a significant difference between patients with TSHomas and control subjects (p = 0.026). The mean LAD values were 36.9 ± 7.1, 38.2 ± 8.9, and 28.7 ± 3.9 mm for patients with TSHomas and GD and control subjects, respectively. There were no significant differences in other echocardiographic parameters among the groups. Before treatment, serum thyroid hormone levels (free triiodothyronine and thyroxin) were not significantly different among patients with TSHomas and GD.

CONCLUSION

We found that patients with TSHomas or GD had enlarged LADs. This finding suggests that AF may be more hidden in patients with TSHomas than previously reported.

Clinical relevance of tumor consistency in pituitary adenoma

PURPOSE

To review the clinical relevance of pituitary adenoma (PA) consistency and its relationship to clinical presentation, radiologic and histopathological characteristics, and surgical outcomes.

BACKGROUND

PA consistency is a critical factor influencing operative planning, surgical outcomes, and patient counseling. There is no validated classification of PA consistency in the literature, and there are no current preoperative variables capable of predicting it.

REVIEW

We conducted a thorough literature review of the Medline, Embase, Web of Science, and Cochrane Library databases. The inclusion criteria were all articles that described PA consistency and correlated it with preoperative aspects, radiological, pathological, and operative findings, or clinical outcomes.

DISCUSSION

Although most authors differentiate easily aspirated (soft) tumors from those that are not (fibrous, might require prior fragmentation), there is no universally accepted PA consistency classification. Fibrous PA tends to be hypointense on T2WI and has lower apparent diffusion coefficient (ADC) values. Fibrous tumors seemed to present higher invasion into neighboring structures, including the cavernous sinus. Several articles suggest that dopamine agonists could increase PA consistency and that prior surgery and radiotherapy also make PA more fibrous. The anatomopathological studies identify collagen as being mainly responsible for fibrous consistency of adenomas.

CONCLUSIONS

Preoperative knowledge of PA consistency affords the neurosurgeon substantial benefit, which clearly appears to be relevant to surgical planning, risks, and surgery outcomes. It could also encourage the centralization of these high complexity tumors in reference centers. Further studies may be enhanced by applying standard consistency classification of the PA and analyzing a more extensive and prospective series of fibrous PA.

A challenging TSH/GH co-secreting pituitary adenoma with concomitant thyroid cancer; a case report and literature review

BACKGROUND

Thyroid stimulating hormone (TSH) secreting pituitary adenoma (TSHoma) with coexisting thyroid cancer is extremely rare, and proper treatment of both diseases may pose a unique clinical challenge. When TSHoma has plurihormonality, particularly involving the co-secretion of growth hormone (GH), management can be more complicated. Herein, we present a difficult-to-manage case of papillary thyroid cancer with an incurable TSH/GH-secreting pituitary adenoma.

CASE PRESENTATION

A 59-year-old man was referred to our hospital due to memory impairment and inappropriate TSH level. Sella magnetic resonance imaging revealed a huge pituitary mass extending to the suprasellar area. Clinical diagnosis of TSH/GH co-secreting pituitary adenoma was made based on elevated free T4, total T3, serum α-subunit, insulin-like growth factor-1 levels and non-suppressible GH levels after oral glucose loading. Rectal cancer and multifocal papillary thyroid microcarcinoma (PTMC) were diagnosed during initial screening for internal malignancy; lower anterior resection was performed and close observation was planned for PTMC. Long-acting octreotide therapy was commenced, which resulted in a dramatic reduction in TSHoma size and facilitated control of hormonal excess. Total thyroidectomy and radioactive iodine (RAI) therapy were needed during follow up due to the growth of PTMC. After the surgery, the pituitary adenoma represented resistance to somatostatin analogue therapy and the tumor size gradually increased despite the addition of dopamine agonist therapy. Furthermore, TSH suppressive therapy with levothyroxine was impossible and an adequate TSH level for RAI therapy was unmountable. Late debulking pituitary surgery was ineffective, and the patient gradually deteriorated and lost to follow up.

CONCLUSION

We report the first aggravated case of TSH/GH co-secreting pituitary tumor after total thyroidectomy for concomitant multifocal PTMC. Deferring of thyroid surgery until the TSHoma is well controlled may be the optimal therapeutic strategy in patients with TSHoma and coexistent thyroid cancer; ablative thyroid surgery may result in catastrophic pituitary tumor growth.

Consistency of Pituitary Adenoma: Prediction by Pharmacokinetic Dynamic Contrast-Enhanced MRI and Comparison with Histologic Collagen Content

Simple Summary

Transsphenoidal resection of hard pituitary adenomas have a particularly high risk of residual tumor and complications. Therefore, prediction of tumor consistency is valuable for planning pituitary adenoma surgery. We prospectively examined whether quantitative pharmacokinetic analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is useful for predicting consistency of pituitary adenoma in 49 participants. We found that the measure of volume of extravascular extracellular space per unit volume of tissue derived from DCE-MRI could predict the consistency of pituitary adenomas. Furthermore, the volume of extravascular extracellular space per unit volume of tissue was significantly positively correlated with histopathologic collagen content of the adenoma. Our results suggest that volume of extravascular extracellular space per unit volume of tissue derived from quantitative pharmacokinetic analysis of DCE-MRI has a predictive value for consistency of pituitary adenomas.

Abstract

Prediction of tumor consistency is valuable for planning transsphenoidal surgery for pituitary adenoma. A prospective study was conducted involving 49 participants with pituitary adenoma to determine whether quantitative pharmacokinetic analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is useful for predicting consistency of adenomas. Pharmacokinetic parameters in the adenomas including volume of extravascular extracellular space (EES) per unit volume of tissue (v_e), blood plasma volume per unit volume of tissue (v_p), volume transfer constant between blood plasma and EES (K^trans), and rate constant between EES and blood plasma (k_ep) were obtained. The pharmacokinetic parameters and the histologic percentage of collagen content (PCC) were compared between soft and hard adenomas using Mann–Whitney U test. Pearson’s correlation coefficient was used to correlate pharmacokinetic parameters with PCC. Hard adenomas showed significantly higher PCC (44.08 ± 15.14% vs. 6.62 ± 3.47%, p < 0.01), v_e (0.332 ± 0.124% vs. 0.221 ± 0.104%, p < 0.01), and K^trans (0.775 ± 0.401/min vs. 0.601 ± 0.612/min, p = 0.02) than soft adenomas. Moreover, a significant positive correlation was found between v_e and PCC (r = 0.601, p < 0.01). The v_e derived using DCE-MRI may have predictive value for consistency of pituitary adenoma.

Preoperative and long-term efficacy and safety of lanreotide autogel in patients with thyrotropin-secreting pituitary adenoma: a multicenter, single-arm, phase 3 study in Japan

Somatostatin analogs are recommended for pharmacotherapy of TSH-secreting pituitary adenoma (TSHoma). A multicenter clinical trial was conducted to evaluate the efficacy and safety of lanreotide autogel treatment for TSHoma. A total of 13 Japanese patients with TSHoma were enrolled from February to December 2018 and treated with lanreotide autogel 90 mg every 4 weeks, with dose adjustments to 60 mg or 120 mg. Analysis was performed on data from patients receiving preoperative treatment (n = 6) up to 24 weeks and from those receiving primary or postoperative treatment (n = 7) up to 52 weeks. The primary efficacy endpoints were serum concentrations of TSH, free triiodothyronine (FT3), and free thyroxine (FT4). The secondary efficacy endpoints were pituitary tumor size and clinical symptoms. The serum concentrations of TSH, FT3, and FT4 decreased with treatment, and euthyroid status was maintained until final assessment. FT4 at final assessment was within reference ranges in 10/13 patients. The median (interquartile range) percent change in pituitary tumor size from baseline at final assessment was -23.8% (-38.1, -19.8). The clinical symptoms were also improved. The patients receiving preoperative treatment did not develop perioperative thyroid storm. Regarding safety, adverse events were observed in 12/13 patients, but none discontinued treatment. The common adverse events were gastrointestinal disorders (12/13 patients) and administration site reactions (5/13 patients). Lanreotide autogel may be effective for controlling thyroid function and reducing the pituitary tumor size, and is tolerable in patients with TSHoma (Japic Clinical Trials Information; JapicCTI-173772).

Neuropathology of Pituitary Adenomas and Sellar Lesions

The pituitary gland is the site of numerous neoplastic and inflammatory processes. The overwhelmingly most frequent tumors arise from cells of the anterior lobe, the pituitary neuroendocrine tumors (PitNETs). Immunohistochemistry assay staining for pituitary hormones is the core tool for classifying PitNETs, resulting in the diagnosis of somatotroph PitNETs, lactotroph PitNETs, and so on. For cases showing no hormonal expression, the updated WHO classification system now considers the assessment of several transcription factors: PIT-1 (pituitary-specific POU-class homeodomain transcription factor); T-PIT (T-box family member TBX19); and SF-1 (steroidogenic factor regulating gonadotroph cell differentiation) before rendering a diagnosis of null cell adenoma. Other tumors and disease processes of this site often mimic PitNETs radiographically and sometimes even clinically (ie, compression of the optic chiasm). These potpourri of processes include germ cell neoplasms (especially germinomas), tumors that originate from Rathke's pouch (craniopharyngiomas, Rathke's cleft cyst), tumors that originate from the posterior lobe of the pituitary (pituicytoma, spindle cell oncocytoma, granular cell tumor), and tumors that originate from the meninges (especially meningiomas). In addition to neoplasms, several described inflammatory and related conditions exist that need to be distinguished from PitNETs. These include lymphocytic hypophysitis and Langerhans cell histiocytosis, a neoplastic disorder of histiocytes. In this review, we aim to briefly describe the main pituitary and sellar lesions, with emphasis on the most common tumors, the PitNETs.

Clinical characteristics and thyroid hormone dynamics of thyrotropin-secreting pituitary adenomas at a single institution

PURPOSE

Thyrotropin-secreting pituitary adenomas (TSPA) are extremely rare pituitary adenomas; their perioperative thyroid hormone dynamics have not been completely elucidated. Here, we investigated the clinical characteristics, perioperative findings, and thyroid hormone dynamics of TSPA at a single institution.

METHODS

We enrolled 11 patients who underwent transsphenoidal surgery (TSS) for TSPA during 2005-2019 at Hiroshima University Hospital (TSPA group) and 24 patients who underwent TSS for nonfunctioning pituitary adenomas (NFPA) in 2019 (NFPA group; for comparison). Their clinical characteristics, operative findings, and thyroid hormone dynamics, including serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4), were retrospectively analyzed.

RESULTS

The NFPA group demonstrated a slight temporary decrease in serum TSH/ FT3/ FT4 levels on day 1 postoperatively and improvement in the levels on day 4 postoperatively. In contrast, the serum TSH level in the TSPA group demonstrated a marked decrease on day 1 postoperatively but improved on day 7 postoperatively. The serum FT3 level was also markedly decreased on day 1 postoperatively but remained within the normal range. The serum FT4 level revealed a gradual decrease until day 21 postoperatively and then recovered within the normal range 3 months postoperatively. There was no significant difference in the frequency of decline in serum FT4 level between the two groups; no patients required thyroid hormonal replacement 3 months postoperatively.

CONCLUSIONS

Despite a variable degree of transient hypothyroidism, all patients had a normal thyroid function after 3 months follow-up.

An Update on the Pathophysiology and Diagnosis of Inappropriate Secretion of Thyroid-Stimulating Hormone

Inappropriate secretion of thyroid-stimulating hormone (IST), also known as central hyperthyroidism, is a clinical condition characterized by elevated free thyroxine and triiodothyronine concentrations concurrent with detectable thyroid-stimulating hormone (TSH) concentrations. Similarly, the term syndrome of IST (SITSH) is widely used in Japan to refer to a closely related condition; however, unlike that for IST, an elevated serum free triiodothyronine concentration is not a requisite criterion for SITSH diagnosis. IST or SITSH is an important indicator of resistance to thyroid hormone β (RTHβ) caused by germline mutations in genes encoding thyroid hormone receptor β (TRβ) and TSH-secreting pituitary adenoma. Recent evidence has accumulated for several conditions associated with IST, including RTH without mutations in the TRβ gene (non-TR-RTH), the phenomenon of hysteresis involving the hypothalamus-pituitary-thyroid axis (HPT-axis), methodological interference, and Cushing’s syndrome after surgical resection. However, little information is available on the systematic pathophysiological aspects of IST in previous review articles. This report presents an overview of the recent advances in our understanding of the etiological aspects of IST that are relevant for diagnosis and treatment. Moreover, the report focuses on the potential mechanism of IST caused by hysteresis in the HPT-axis (lagging TSH recovery) in terms of epigenetic regulation.

Diagnostic value of Knosp grade and modified Knosp grade for cavernous sinus invasion in pituitary adenomas: a systematic review and meta-analysis

OBJECTIVE

This study aimed to examine the reliability of existing Knosp grade (KG) and modified KG for cavernous sinus invasion (CSI).

METHODS

A thorough search of literature from 1993 to 2020 in six databases was performed. Studies that reported the intraoperative confirmation of CSI using KG and/or modified KG were included. The pooled estimates were calculated by meta-analysis with a bivariate mixed-effect model and the assessment of heterogeneity with I² statistic.

RESULTS

The final search yielded 12 eligible studies, which enrolled 3006 patients assessed with KG and 1315 patients assessed with modified KG. The results of the area under the receiver operating characteristic curve showed the good discriminative abilities of grades 2-4 (0.90), 3-4 (0.86) and 3B-4 (0.91) in predicting CSI. Grade 3A showed a remarkably lower CSI rate (44% versus 81%) and incomplete resection rate (26% versus 52%) than grade 3B. Grades 0 and 1 showed a low CSI rate. CSI and incomplete resection rates in grade 2 (30% and 21%, respectively) were close to those in grade 3A.

CONCLUSIONS

Modifying the KG improved its prognostic role in CSI and gross total resection. However, these grading systems cannot be used as the group standard for invasive and non-invasive pituitary adenomas (PAs) because of the weak reliability of the scale's middle grades (grades 2 and 3A). Authors of future PA studies should consider reporting KG as high (grades 3B and 4), medium (grades 2 and 3A) and low (grades 0 and 1) to optimise the application of the scale.

The outcome of TSHoma from a tertiary care institute in India

Background:

Thyroid-stimulating hormone (TSH)-secreting pituitary adenoma (TSHoma) is the rarest functioning pituitary adenoma.

Methods:

A retrospective analysis of eight patients of TSHomas to highlight the presentations, diagnostic challenges, and treatment outcomes.

Results:

Median age at diagnosis was 42 years, median latency to diagnosis was 2.5 years, and thyrotoxic and compressive symptoms were the most common presenting symptoms. At presentation, three cases were plurihormonal, six cases were on medical treatment including thyroxine, and two cases were incidentally discovered. Imaging revealed macroadenoma in all cases. Seven cases underwent pituitary surgery, after which three achieved remission. Another case entered remission after adjunctive radiotherapy. Thyrotropin (TSH) immunostaining was demonstrated in six out of seven adenomas.

Conclusion:

TSHoma is a rare functioning pituitary tumor with both silent and symptomatic presentations. Diagnosis can be established with biochemical and imaging features, even without dynamic tests.

Pituitary thyrotoxicosis presenting as abnormal thyroid function testing during pregnancy: a case report

BACKGROUND

Central hyperthyroidism is a rare form of hyperthyroidism caused by thyrotrope pituitary adenomas. It is characterized by elevated thyroid-stimulating hormone alongside high thyroxine and triiodothyronine. Goiter is the most common symptom of central hyperthyroidism. Surgical resection as well as somatostatin analog therapy typically achieve resolution of hyperthyroid symptoms and restoration of a euthyroid state.

CASE PRESENTATION

We report the case of a 30-year-old primigravida Caucasian/White female who presented with abnormal thyroid function testing results and multinodular goiter during pregnancy. Postpartum, she was found to have multinodular goiter on physical examination as well as persistent elevated thyroid-stimulating hormone with elevated free thyroxine and free triiodothyronine. Magnetic resonance imaging disclosed a large pituitary macroadenoma, and she subsequently underwent resection of the mass. She achieved a sustained euthyroid state postoperatively.

CONCLUSIONS

This case shows how central hyperthyroidism can present without the more apparent symptoms of thyrotoxicosis and that successful resolution of central hyperthyroidism may be achieved postoperatively.

Proton and Heavy Particle Intracranial Radiosurgery

Stereotactic radiosurgery (SRS) involves the delivery of a highly conformal ablative dose of radiation to both benign and malignant targets. This has traditionally been accomplished in a single fraction; however, fractionated approaches involving five or fewer treatments have been delivered for larger lesions, as well as lesions in close proximity to radiosensitive structures. The clinical utilization of SRS has overwhelmingly involved photon-based sources via dedicated radiosurgery platforms (e.g., Gamma Knife® and Cyberknife®) or specialized linear accelerators. While photon-based methods have been shown to be highly effective, advancements are sought for improved dose precision, treatment duration, and radiobiologic effect, among others, particularly in the setting of repeat irradiation. Particle-based techniques (e.g., protons and carbon ions) may improve many of these shortcomings. Specifically, the presence of a Bragg Peak with particle therapy at target depth allows for marked minimization of distal dose delivery, thus mitigating the risk of toxicity to organs at risk. Carbon ions also exhibit a higher linear energy transfer than photons and protons, allowing for greater relative biological effectiveness. While the data are limited, utilization of proton radiosurgery in the setting of brain metastases has been shown to demonstrate 1-year local control rates >90%, which are comparable to that of photon-based radiosurgery. Prospective studies are needed to further validate the safety and efficacy of this treatment modality. We aim to provide a comprehensive overview of clinical evidence in the use of particle therapy-based radiosurgery.

Clinical and Therapeutic Characteristics of Pituitary TSH-Secreting Adenoma in Adolescent-Onset Patients: Six Case Studies and Literature Review

BACKGROUND

Thyrotropin-secreting adenoma (TSH-oma) is a very rare kind of functional pituitary adenoma, especially that which occurs in adolescents. However, its potential clinical and therapeutic characteristics are still unknown.

OBJECTIVES

The study was aimed to summarize the clinical and therapeutic characteristics of patients with adolescent-onset TSH-oma.

METHODS

We retrospectively analyzed six (4.1%) adolescent-onset TSH-oma cases from 148 patients who were diagnosed with TSH-oma at our hospital between January 2012 and October 2020. A literature review was performed on the PubMed online database, and 14 adolescent-onset TSH-oma cases were retrieved. Then, the characteristics of clinical manifestations, treatment outcomes, and follow-ups were analyzed and compared to the adult TSH-oma patients.

RESULTS

Altogether, 20 adolescent-onset cases were included in this study having mean onset age of 13.4 ± 3.3 years. Males were found to be slightly predominant (M: F = 1.5:1) in our study. The median baseline levels of TSH, FT3, and FT4 in adolescent-onset cases were found to be 6.30 [interquartile range (IQR) 9.82] µIU/ml, 9.18 (IQR 11.61) pg/ml, and 3.22 (IQR 1.90) ng/dl, respectively, which were all significantly higher than the adult patients of our hospital. Also, the adolescent-onset cases showed more large tumor ratio (36.8% vs. 9.3%, p = 0.007) compared to the adult patients. Compared to the patients of all ages in the literature, the biochemical remission rate of SSAs (57.1%) and remission rate of TSS (38.9%) were found to be considerably lower in adolescent-onset patients, while the recurrence rate (44.4%) was found to be considerably higher.

CONCLUSIONS

Adolescent-onset TSH-oma patients showed higher TSH and thyroid hormone levels, more large tumors, and worse treatment outcomes than adult cases. Hence, early diagnosis, multidisciplinary therapy, and close follow-up should be highlighted to improve the prognosis.

Incidence and Factors Associated with Postoperative Delayed Hyponatremia after Transsphenoidal Pituitary Surgery: A Meta-Analysis and Systematic Review

INTRODUCTION

Postoperative delayed hyponatremia is a complication associated with transsphenoidal pituitary surgery. Due to a wide spectrum of symptoms, the reported incidence and predictors of postoperative delayed hyponatremia vary among studies, and this deserves to be reviewed systematically.

METHODS

PubMed, EMBASE, and CENTRAL databases were searched until September 1, 2020. Studies were included when (1) the event number of delayed hyponatremia after transsphenoidal pituitary surgery was reported, or (2) the associated factors of such complication were evaluated.

RESULTS

A total of 27 studies were included for meta-analysis. The pooled incidence of overall and symptomatic delayed hyponatremia was 10.5% (95% confidence interval (CI) = 7.4-14.7%) and 5.0% (95% CI = 3.6-6.9%), respectively. No overt variations of the pooled estimates were observed upon subgroups stratified by endoscopic and microscopic procedure, publication year, and patients' age. In addition, 44.3% (95% CI = 29.6-60.2%) of unplanned hospital readmissions within 30 days were caused by delayed hyponatremia. Among the predictors evaluated, older age was the only significant factor associated with increased delayed hyponatremia (odds ratio = 1.16, 95% CI = 1.04-1.29, P = 0.006).

CONCLUSION

This meta-analysis and systematic review evaluated the incidence of postoperative delayed hyponatremia and found it as a major cause of unplanned readmissions after transsphenoidal pituitary surgery. Older patients are more prone to such complications and should be carefully followed. The retrospective nature and heterogeneity among the included studies and the small number of studies used for risk factor evaluation might weaken the corresponding results. Future prospective clinical studies are required to compensate for these limitations.

Proposal of a clinically relevant working classification of pituitary neuroendocrine tumors based on pituitary transcription factors

The immunohistochemistry (IHC) characterization of pituitary transcription factors (PTFs) PIT1, TPIT, and SF1, which enable the identification of three different adenohypophyseal cell lines, has been incorporated into the latest classification system of the World Health Organization (WHO) for pituitary adenomas. This change overturns the concept of the adenoma as solely a hormone producer and classifies these tumors based on their cell lineage. The aim of the study was to provide a diagnostic algorithm, based on IHC expression of hypophyseal hormones with potential use in diagnostic practice, contributing to an improved classification of pituitary adenomas. Our sample included 146 pituitary adenomas previously classified based on hormonal subtypes by IHC (former 2004 WHO criteria) and re-evaluated after the IHC quantification of PIT1, TPIT, and SF1 expression, under WHO 2017 recommendations. We assessed the correlation between expression of PTFs and the classification as per hormonal IHC and correlated clinicopathological profiles based on PTFs. The IHC study of PTFs allowed reclassification of 82% of tumors that were negative for all pituitary hormones, with 21 positive cases for SF1 (reclassified as gonadotroph tumors), 1 positive case for TPIT (reclassified as a corticotroph tumor), and 4 positive cases for PIT1. Using SF1 enabled detection of a substantial portion of gonadotroph tumors, reducing the estimated prevalence of null cell tumors to less than 5%, and identification of plurihormonal pituitary neuroendocrine tumors with PIT1-SF1 coexpression and hormone-negative PIT1s, a group in which we did not observe differences in the clinical behavior compared with the rest of the tumors of the same cell lineage.Our results suggest that applying a diagnostic algorithm based on the study of PTFs could contribute to improving the classification of pituitary adenomas. By adding TPIT assessment, we propose a two-step algorithm, with hypophyseal hormones being used in a selective modality, depending on initial results.

Cosecreting TSH/GH pituitary adenomas-an 8-year experience in a single tertiary center

PURPOSE

Thyrotropin-secreting pituitary adenoma is a rare disorder and was recently classified as an aggressive tumor in the World Health Organization guidelines. The number of available studies on cosecreting thyrotropin/growth hormone pituitary adenoma is especially limited.

METHODS

A single-center retrospective analysis of patients with thyrotropin/growth hormone pituitary adenoma was performed at Peking Union Medical College Hospital, one of the largest pituitary care centers in China, from January 2012 to January 2020. Additionally, data about cosecreting thyrotropin/growth hormone pituitary adenoma were collected and analyzed. The diagnosis, therapy and follow-up were all compared to that of solo-secreting thyrotropin pituitary macroadenoma.

RESULTS

Twelve patients (10.81%) were identified with thyrotropin/growth hormone pituitary adenoma at Peking Union Medical College Hospital within 8 years, all of which were classified as macroadenoma. Compared with solo-secreting thyrotropin pituitary macroadenoma, thyrotropin/growth hormone pituitary adenoma presented with a higher proportion of cavernous sinus invasion (50%) and had a larger maximum tumor diameter. The patients had a lower surgical complete remission rate and a worse prognosis. Interestingly, they revealed a striking phenomenon of "solo part remission".

CONCLUSIONS

Thyrotropin/growth hormone pituitary adenoma is rare. Some patients do not present with the typical manifestations; however, the possibility of a cosecretion tumor should not be excluded. A preoperative comprehensive evaluation of anterior pituitary hormones is necessary. Thyrotropin/growth hormone pituitary adenoma revealed a high tendency of invasion, and the prognosis of patients with thyrotropin/growth hormone pituitary adenoma was poor. If necessary, timely postoperative drug administration or radiotherapy should be carried out.

Ki67 in endocrine neoplasms: to count or not to count, this is the question! A systematic review from the English language literature

BACKGROUND

Endocrine neoplasms are generally slow-growing tumors that can show hormonal activity and give metastases. In most cases they are benign and clearly malignant forms are easy to diagnose. However, borderline forms may occur and be, for the pathologists, very difficult to classify. In these cases, there is a strong need to identify factors that may aid. Official classification systems for endocrine neoplasms are based on the evaluation of proliferation and, in most cases, they rely on mitotic count. In support, the study of Ki67 is carried out which, however, has not yet been included in any official classification system, except for neuroendocrine neoplasms of the gastro-entero-pancreatic tract.

PURPOSE

The aim of the present study was to investigate the proven or unproven role of Ki67 in endocrine neoplasms, in different districts, in order to bring to light the substantial differences, in terms of proliferation, existing between neoplasms so similar, but at the same time, so different.

METHODS

A thorough search of English language literature was performed, looking for articles concerning Ki67 in five endocrine neoplasms (pituitary adenomas, thyroid neoplasms, adrenocortical neoplasms, pheochromocytomas and paragangliomas).

RESULTS

From 2170, 236 articles were selected and it was seen that the endocrine neoplasm in which Ki67 was most studied was the pituitary, where it still shows a controversial role. In other neoplasms different roles were identified.

CONCLUSION

The pathologist should be aware of the contribution that this proliferative marker can give to the diagnosis and, sometimes, to the therapy selection, for the clinician.

Autophagy and Pituitary Adenoma

Pituitary adenomas (PAs) are common, benign intracranial tumors that are usually effectively controlled with surgery, pharmacotherapy or radiotherapy. Some PAs against which conventional treatment is ineffective are great clinical challenges at present. Autophagy is a widespread physiological process in cells. Through autophagy, cells can degrade damaged or redundant proteins and organelles and achieve the recycling of intracellular substances to maintain the homeostasis of the intracellular environment. An increasing number of studies have demonstrated the importance of autophagy in tumor therapy. Both radiotherapy and chemotherapy can induce autophagy, which plays different roles in the course of therapy. In recent years, there has been growing interest in the role of autophagy during the treatment of PAs. This chapter reviews the recent progress of research on autophagy in PA and the autophagic mechanisms in the treatment of PA.

Pediatric pituitary adenoma with mixed FSH and TSH immunostaining and FSH hypersecretion in a 6 year-old girl with precocious puberty: case report and multidisciplinary management

OBJECTIVE

We describe a rare case of functioning gonadotropins-producing pediatric adenoma immunostaining positively for FSH and focally for TSH causing central precocious puberty associated to central hypothyroidism in a 6 year-old girl.

MATERIALS AND METHODS

Clinical evaluation revealed precocious puberty, as confirmed by hormonal determination with elevated FSH and estradiol, while central hypothyroidism was biochemically diagnosed by a low fT4 and normal TSH. Head MRI showed the presence of a hyperintense pituitary lesion. The patient successfully underwent transsphenoidal endoscopic resection of the pituitary macroadenoma.

RESULTS

Pathologic evaluation of the tissue resected at surgery confirmed the diagnosis of pituitary adenoma with positive immunohistochemistry for FSH and focally for TSH in a mixed pattern. Ten months after surgery, there were no neurological signs and symptoms. Postoperative head MRI showed no abnormalities and no evidence of tumor regrowth.

CONCLUSIONS

Early and accurate diagnosis, multidisciplinary approach and close follow up are crucial factors for the favorable outcome.

Epidemiology of Functioning Pituitary Adenomas

Pituitary adenomas (PAs) are defined as benign monoclonal tumors in the pituitary gland that cause symptoms due to either hormonal hypersecretion or a space-occupying effect, and are classified as functioning or non-functioning. Because of their rarity and slow-growing with symptomless nature in most cases, it has been challenging to investigate the epidemiology of PAs. Considering their public health impact and association with increased morbidity and mortality, however, it is essential to understand the prevalence and incidence of PAs in order to improve patient outcomes and to minimize the resultant burden on the health care system. Fortunately, developments in imaging modalities and easier access to large-scale population data have enabled investigators to analyze the epidemiology of PAs more accurately. This review summarizes previously reported epidemiologic data on functioning PAs in Korea and other countries.

Immediate postoperative measurement of thyroid-stimulating hormone as an early predictor of remission in thyroid-stimulating hormone-secreting pituitary adenomas

OBJECTIVE

Thyroid-stimulating hormone (TSH)-secreting pituitary adenoma (TSHoma) is a rare type of pituitary adenoma; thus, little is known about TSHomas. The purpose of this study was to analyze clinical characteristics and therapeutic outcomes of TSHomas based on a single-center experience. The authors also searched for reliable preoperative and early postoperative factors that could predict long-term endocrinological remission.

METHODS

The clinical, radiological, and pathological characteristics and surgical and endocrinological outcomes of 31 consecutive cases of TSHomas that were surgically treated between 2005 and 2017 were reviewed retrospectively. Preoperative factors were evaluated for their ability to predict long-term remission by comparing remission and nonremission groups. TSH and free thyroxine levels were measured at 2, 6, 12, 18, and 24 hours after surgery to determine whether they could predict long-term remission.

RESULTS

Gross-total removal of tumor was achieved in 28 patients (90.3%), and 26 patients (83.9%) achieved endocrinological remission by surgery alone based on long-term endocrinological follow-up (median 50 months, range 32-81 months). The majority of the tumors were solid (21/31, 67.7%), and en bloc resection was possible in 16 patients (51.6%). Larger tumor size and tumor invasion into cavernous sinus and sphenoid sinus were strong predictors of lower rates of endocrinological remission. Immediate postoperative TSH level at 12 hours after surgery was the strongest predictor, with a 0.62 μIU/mL cutoff. Postoperative complications included CSF rhinorrhea in one patient and epistaxis in another patient, who underwent additional surgical treatment for the complications.

CONCLUSIONS

Tumor size and extent are major prognostic factors for both extent of resection and endocrinological remission. The consistency of TSHomas was more likely to be solid, which makes extracapsular dissection more feasible. Long-term remission of TSHomas could be predicted even during the early postoperative period.

Thyroid-Stimulating Hormone-Secreting Pituitary Adenomas : Single Institutional Experience of 14 Consecutive Cases

OBJECTIVE

Thyroid-stimulating hormone (TSH)-secreting pituitary adenoma (PA) is an extremely rare functioning form of PA that accounts for 0.7-2% of all such cases. The previously reported outcomes of the surgical removal of TSH-PA are poor. Owing to its extremely low incidence, most available reports on TSH-PA are case reports or small case series. Thus, we investigated the clinical and endocrinological outcomes of surgically treated TSH-PA through our institutional series.

METHODS

We retrospectively reviewed 14 consecutive cases of surgically treated TSH-PA, focusing on the clinical, radiological, surgical, and endocrinological data.

RESULTS

There were seven male (50%) and seven female (50%) patients. The mean age was 42.5 years (range, 19-63). The mean tumor size was 16.6 mm (range, 4-30). Optic chiasm compression was noted in six patients (42.9%), and no patient showed cavernous sinus invasion. Thirteen of 14 patients (92.8%) underwent transnasal transsphenoidal approach (TSA), and one patient underwent TSA followed by transcranial approach for residual tumor removal. Thirteen of 14 patients (92.8%) showed endocrinological remission; all patients who experienced remission showed subnormal levels of TSH (<0.4 μU/mL) on postoperative day 2. Recurrence occurred in two patients (14.2%). One patient underwent subsequent revision transnasal TSA for recurrent tumor removal, and the other patient underwent gamma knife radiosurgery for recurrence.

CONCLUSION

Surgical treatment showed excellent surgical outcomes. The TSH level in the immediate postoperative period may be a predictor for endocrinological remission.

Clinicopathological analysis of 250 cases of pituitary adenoma under the new WHO classification

Pituitary adenomas (PAs) are a common subtype of intracranial tumors. The aim of the present study was to analyse the clinical and pathological features of different types of pituitary adenomas (PAs) according to the 2017 World Health Organisation Endocrine Organ Tumor Classification guidelines. The clinical data of 250 patients with PAs were collected and analysed. Differences in the incidence of invasion, recurrence and apoplexy in patients between high- and low-risk PAs were compared, as were differences in the Ki-67 index between invasive and non-invasive PAs and between recurrent PAs and non-recurrent PAs. Of the 250 cases, 45 cases were diagnosed as somatotroph adenomas, 26 cases as lactotroph adenomas, 1 case as thyrotroph adenoma, 61 cases as corticotroph adenomas, 93 cases as gonadotropin adenomas, 15 cases as null cell adenomas and 9 cases as plurihormonal adenomas. There were 5 types of high-risk pituitary adenoma identified: 17 cases of sparsely granulated somatotroph adenoma, 11 cases of lactotroph adenoma in men, 3 cases of plurihormonal PIT-1 positive adenoma and 42 cases of silent corticotroph adenoma. Crooke's cell adenoma was not identified. High-risk PAs had significantly higher rates of invasion, recurrence and apoplexy compared with that in low-risk types (P<0.001). Invasive PAs had a significantly higher Ki-67 index compared with that in non-invasive PAs (3.5±1.8 vs. 2.8±1.3; P<0.01). Recurrent PAs had a significantly higher Ki-67 index compared with that in non-recurrent PAs (3.9±1.9 vs. 2.8±1.3; P<0.001). According to the 2017 classification criteria, patients most frequently had gonadotrophin cell adenomas, followed by corticotroph adenomas and the proportion of null cell adenomas was reduced. Differences were noted in the proliferation, recurrence and apoplexy characteristics of high-risk PAs and low-risk PAs. The invasion and recurrence of PAs were found to be related to the Ki-67 index.

The Differential Diagnosis of Discrepant Thyroid Function Tests: Insistent Pitfalls and Updated Flow-Chart Based on a Long-Standing Experience

Background: Discrepant thyroid function tests (TFTs) are typical of inappropriate secretion of TSH (IST), a rare entity encompassing TSH-secreting adenomas (TSHoma) and Resistance to Thyroid Hormone (RTHβ) due to THRB mutations. The differential diagnosis remains a clinical challenge in most of the cases. The objective of this study was to share our experience with patients presenting with discrepant TFTs outlining the main pitfalls in the differential diagnosis. Methods: medical records of 100 subjects with discrepant TFTs referred to Thyroid Endocrine Centers at the University of Milan were analyzed, retrospectively. Patients were studied by dynamic testing (TRH test, T3-suppression test, or a short course of long-acting somatostatin analog, when appropriate), THRB sequencing, and pituitary imaging. Results: 88 patients were correctly diagnosed as RTHβ with (n = 59; 16 men, 43 women) or without THRB variants (n = 6; 2 men, 4 female) or TSHoma (n = 23; 9 men, 14 women). We identified 14 representative subjects with an atypical presentation or who were misdiagnosed. Seven patients, with spurious hyperthyroxinemia due to assays interference were erroneously classified as RTHβ (n = 4) or TSHoma (n = 3). Three patients with genuine TSHomas were classified as laboratory artifact (n = 2) or RTHβ (n = 1). Two TSHomas presented atypically due to coexistent primary thyroid diseases. In one RTHβ a drug-induced thyroid dysfunction was primarily assumed. These patients experienced a mean diagnostic delay of 26 ± 14 months. Analysis of the investigations which can differentiate between TSHoma and RTHβ showed highest accuracy for the T3-suppression test (100% specificity with a cut-off of TSH <0.11 μUI/ml). Pituitary MRI was negative in 6/26 TSHomas, while 11/45 RTHβ patients had small pituitary lesions, leading to unnecessary surgery in one case. Conclusions: Diagnostic delay and inappropriate treatments still occur in too many cases with discrepant TFTs suggestive of central hyperthyroidism. The insistent pitfalls lead to a significant waste of resources. We propose a revised flow-chart for the differential diagnosis.

Progress in the Pathogenesis, Diagnosis, and Treatment of TSH-Secreting Pituitary Neuroendocrine Tumor

TSH-secreting pituitary neuroendocrine tumor (PitNET) is one of the causes of central hyperthyroidism. The incidence of TSH PitNET is far lower than that of other PitNETs. The clinical manifestations of TSH PitNETs mainly include thyrotoxicosis or thyroid goiter, secretion disorders of other anterior pituitary hormones, and mass effect on the pituitary gland and its surrounding tissues. The application of high-sensitivity TSH detection methods contributes to the early diagnosis and timely treatment of TSH PitNETs. Improvements in magnetic resonance imaging (MRI) have advanced the noninvasive visualization of smaller PitNETs. Treatments for TSH PitNETs include surgery, drugs, and radiotherapy. This review focuses on the progress in pathogenesis, diagnosis, and treatment of TSH PitNETs to provide more information for the clinician.

A 2019 update on TSH-secreting pituitary adenomas

Thyrotropin-secreting pituitary adenomas (TSH-omas) present with signs and symptoms of hyperthyroidism and they are characterized by elevated serum levels of free thyroid hormones with measurable TSH levels. TSH-omas are very infrequent, accounting for less than 1% of all pituitary adenomas, thus representing a very rare cause of hyperthyroidism. For this reason, data collected on these rare disorders are relatively few, but some new researches shed new light on the etiopathogenesis, the diagnosis and the treatment of such a remarkable disease. Since the same biochemical picture is present in the syndromes of thyroid hormone resistance (RTH), in particular in the form of pituitary RTH, failure in distinguishing these clinical entities may lead to improper patient management. Conversely, early diagnosis and correct treatment of TSH-omas may prevent the occurrence of neurological and endocrinological complications, thus leading to a better rate of cure. In the present short review article, the most relevant recent advances in the pathophysiology of TSH-omas are described.

Multimodal therapy in aggressive pituitary tumors

The concept of aggressive pituitary tumor (APT) has been precisely defined in recent years. These tumors are characterized by morphological (radiological or histopathological) data of invasion, proliferative activity superior to that of typical adenomas and a clinical behavior characterized by resistance to standard therapies and frequent recurrences. The absence of cerebrospinal or distant metastases differentiates them from the pituitary carcinoma. APTs account for about 10% of all pituitary neoplasm. Proper diagnostic implies participation not only of radiological and hormonal investigation but also a thorough pathological assessment including proliferation markers and immunohistochemistry for hormones and transcription factors. Surgical resection, aiming gross total resection or tumor debulking, is the mainstay initial therapy in most patients. Most patients with APTs need more than one surgical intervention, pituitary radiation, sometimes on more than one occasion, and multiple sequential or combined medical treatments, to finally be doomed to unusual treatments, such as alkylating agents (temozolomide alone or in combination), molecular targeted therapies, or peptide receptor radionuclide therapy. Multimodal therapy, implemented by experts, preferably in specialized centers with high volume caseload, is the only way to improve the prognosis of patients with these uncommon tumors. The research needs in this area are multiple and include a greater knowledge of the molecular biology of these tumors, establishment of protocols for monitoring and sequencing of treatments, development of multicenter studies and international registries.

Surgical management of clinically silent thyrotropin pituitary adenomas: A single center series of 20 patients

Silent thyrotropin pituitary adenomas (TSHomas) are defined by absence of hyperthyroidism despite TSH immunopositivity. Data pertaining to clinical and surgical characteristics of silent TSHomas remains limited. We aim to describe the clinical presentation, pathological characteristics, and outcomes in silent TSHoma patients treated at a tertiary pituitary center. We retrospectively identified patients with histologically-proven silent TSHoma who underwent transsphenoidal resection at our center between 2000 and 2016 (n = 1244 total patients). Patients with preoperative hyperthyroidism or thyroidectomy were excluded. Twenty patients with silent TSHomas were included (1.6% of surgically treated PAs), of which 35% were reoperations. Presenting symptoms included vision loss (45%) and headache (40%). Preoperative pituitary dysfunction included hypothyroidism (40%), hypogonadotropic hypogonadism (30%), and panhypopituitarism (15%). Nineteen patients (95%) had macroadenomas (mean diameter 29.9 mm). Extrasellar growth was identified in 17 patients (85%) and 65% had cavernous sinus invasion. Immunostaining for alpha-subunit was positive in 19 patients (95%), and 75% of tumors expressed immunopositivity for hormones other than TSH. Gross total tumor resection was achieved in 9 patients (45%) on follow-up MRI. Major postoperative complications included hydrocephalus (1 patient) and cerebrospinal fluid leak with meningitis (1 patient). Tumor progression and recurrence occurred in 1 patient each (10% total) over the follow-up period (median 18.5 months). Silent TSHomas tend to be large, invasive tumors. In addition to TSH, a majority express immunopositivity for alpha-subunit and gonadotropins, thereby potentially supporting a primitive adenoma lineage and subtype. Despite reoperation in several patients, good overall outcomes with low complication rates were achieved.

Peel-off resection of the pituitary gland for functional pituitary adenomas: pathological significance and impact on pituitary function

PURPOSE

Functional pituitary adenomas (FPAs) lacking a well-defined pseudocapsule can invade the adjacent pituitary gland. In such situations, peel-off resection of the adjacent pituitary gland after selective adenomectomy might lead to complete tumor removal, resulting in optimal endocrinological outcomes. Here, we present the significance of peel-off resection of the pituitary gland in patients with FPA in whom complete extracapsular tumor removal cannot be achieved.

METHODS

We performed a retrospective review of 21 patients with FPA who underwent transsphenoidal surgery (TSS). After selective adenomectomy, peel-off resection of the adjacent pituitary gland was performed in 13 patients because complete extracapsular resection could not be achieved, while peel-off resection was not performed in the remaining 8 patients because complete extracapsular resection was accomplished. The clinical outcomes of these groups were compared. The pituitary tissues obtained by peel-off resection were pathologically examined for tumor cells.

RESULTS

Early postoperative biochemical remission was achieved in 20 patients (95.2%). Anterior pituitary functions were not aggravated postoperatively in any patient: however, transient diabetes insipidus (DI) occurred in 2 patients. There were no statistically significant differences in the clinical outcomes of the two groups. A pseudocapsule was pathologically detected in the adjacent anterior pituitary even in patients in whom no pseudocapsule was intraoperatively detected. Tumor cells were pathologically detected in 7 (58.3%) of 12 pituitary tissues examined.

CONCLUSIONS

Peel-off resection of the pituitary gland, which can remove a small tumor cell remnant in the adjacent pituitary, might maximize the effectiveness of TSS with minimal impact on postoperative pituitary function.