Anatomic and pathologic spectrum of pituitary infundibulum lesions

Cerebrospinal Fluid Metabolomic Pattern of Different Pituitary Stalk Lesions

OBJECTIVE

To describe the cerebrospinal fluid (CSF) metabolomic pattern of pituitary stalk lesions.

METHODS

CSF was collected from patients with different pituitary stalk lesions treated at Peking Union Medical College Hospital: germ cell tumor (GCT, n = 27); hypophysitis (n = 10); and Langerhans cell histiocytosis (LCH) or Erdheim-Chester disease (ECD) (LCH + ECD, n = 10). The CSF metabolome profiles were characterized by liquid chromatography-mass spectrometry (LC-MS).

RESULTS

There were 44 metabolites that significantly differed between patients with GCT and those with hypophysitis (P < .05). Between patients with GCT with CSF level of beta subunit of human chorionic gonadotrophin (β-hCG) < 5 mIU/mL and those with hypophysitis, there were 15 differential metabolites (P < .05, fold change > 1.5 or < 1/1.5). All of the metabolites had an area under the curve (AUC) above 0.7. There were 9 metabolites that significantly differed between patients with GCT and those with LCH + ECD (P < .05) and 7 metabolites had significant differences between GCT (CSF β-hCG < 5 mIU/mL) and LCH + ECD (P < .05, fold change > 1.5 or < 1/1.5). We found 6 metabolites that were significantly different between patients with hypophysitis and those with LCH + ECD (P < .05) and 5 of these had fold change more than 1.5 or less than 1/1.5. Three metabolites, 5-deoxydiplosporin, cloversaponin I, and phytosphingosine, showed excellent capabilities to differentiate the 3 disease categories. Furthermore, we identified 67 metabolites associated with clinical test results (ρ > 0.2, P < .05) and 29 metabolites showed strong correlation (ρ > 0.4, P < .05).

CONCLUSION

Our study is the first to systematically investigate the metabolomics of CSF in different pituitary stalk lesions. CSF metabolomics is a useful strategy for biomarker discovery.

A case of pituitary metastasis discovered when diabetes insipidus developed in a patient 20 years after breast cancer treatment

The patient was a 52-year-old woman. She had a history of left breast cancer at age 32 years, with no recurrences. She was examined for a feeling of oral dryness and nocturia, and central diabetes insipidus was diagnosed. A mass was seen in the posterior pituitary on magnetic resonance imaging, and multiple pulmonary nodules were seen on computed tomography. Breast cancer metastases were diagnosed in both tissues. Since this patient had no cancer other than the breast cancer treated 20 years earlier, it was difficult to reach a diagnosis of pituitary metastasis with pituitary gland imaging alone. In estrogen receptor-positive breast cancer, there may be recurrences after a long period of time. It may be that recommending a full body examination could be useful in the differential diagnosis of metastasis even in patients who have had a long disease-free period, if they had undergone surgery for breast cancer.

Is Gadolinium Contrast Necessary for Pituitary MRI in the Evaluation of Pediatric Short Stature and Growth Hormone Deficiency?

INTRODUCTION

Short stature is a common concern that necessitates pediatric endocrinology evaluation. Growth hormone deficiency (GHD) is a commonly considered etiology. Brain and pituitary magnetic resonance imaging (MRI) with gadolinium-based contrast agents (GBCAs) is the most widely used imaging in assessing patients with GHD. Given the significant strides made in MRI technology, the need for contrast material should be reassessed.

METHOD

We performed a retrospective review of healthy patients with short stature and/or GHD who underwent brain and pituitary MRI with and without contrast to assess the added value of contrast administration.

RESULTS

227/318 identified patients underwent growth hormone (GH) stimulation testing; 28 (12.3%) with normal GH response and 62 (27.3%) with severe GHD. We found a low incidence of sellar and suprasellar pathologies. When comparing noncontrast and contrast MRI, we found perfect agreement in detecting abnormal posterior pituitary bright spots (kappa:1.0) and substantial agreement in detecting pars intermedia cysts and posterior superior sellar cysts (kappa: 0.74 and 0.71, respectively). Initially, only moderate agreement was found in detecting infundibular abnormalities (kappa: 0.51), although a revised noncontrast MRI protocol with high-resolution 3D images enabled visualization of the infundibulum.

CONCLUSION

The MRI evaluation of healthy patients with short stature and/or isolated GHD may be completed without the use of GBCAs. The slight overestimation of pituitary stalk interruption by noncontrast images can be overcome by adding newer high-resolution sequences.

Safety of endoscopic endonasal biopsy for the pituitary stalk-hypothalamic lesions

PURPOSE

The indications for and the optimal biopsy approach in pituitary stalk-hypothalamic (PsH) lesions are controversial. Biopsies through an endoscopic endonasal approach (EEA) for PsH lesions have often been considered to cause the infundibulo-tuberal syndrome. The purpose of this study was to analyze the surgical and endocrinological safety of EEA biopsies for PsH lesions.

METHODS

A total of 39 consecutive patients who underwent an EEA biopsy between June 2011 and August 2020 in a single institute were retrospectively analyzed. The ophthalmological and endocrinological outcomes were assessed before and after surgery.

RESULTS

PsH lesions were confirmed to be diverse pathological diagnoses, ranging from lymphocytic hypophysitis to diffuse midline glioma, and the most common pathologic diagnosis was a germinoma (18 patients, 46.2%). No patients developed visual deterioration after the biopsy. In patients without preoperative panhypopituitarism, 13 out of 28 patients (46.4%) developed new anterior pituitary hormonal deficiencies after the biopsy. When the tissue was collected from the stalk, the endocrinological deterioration rate was 100% (6 of 6 patients), while the rate was 31.8% (7 of 22 patients) when tissue could be harvested from an extra-stalk lesion. The rate of newly developed permanent diabetes insipidus after surgery was 40.9% (9 of 22 patients). The median surgery time was 125 min, and there was no postoperative CSF leakage or infections noted.

CONCLUSIONS

An EEA biopsy for PsH lesions is a safe and efficient surgical method unless the tissue is collected from the stalk.

Pituitary Stalk Thickening: Causes and Consequences. The Children's Memorial Health Institute Experience and Literature Review

BACKGROUND

Pituitary stalk thickening (PST) is a rare abnormality in the pediatric population. Its etiology is heterogeneous. The aim of the study was to identify important clinical, radiological and endocrinological manifestations of patients with PST and follow the course of the disease.

MATERIALS AND METHODS

It is a study conducted in 23 patients (13 boys) with PST with/without central diabetes insipidus (CDI) diagnosed between 1990 and 2020 at Children's Memorial Health Institute (CMHI) in Warsaw, Poland. We analyzed demographic data, clinical signs and symptoms, radiological findings, tumor markers, hormonal results, treatment protocols and outcomes.

RESULTS

The median age at the diagnosis of PST was 9.68 years (IQR: 7.21-12.33). The median time from the onset of the symptoms to the diagnosis was 2.17 years (IQR: 1.12-3.54). The most common initially reported manifestations were polydipsia, polyuria and nocturia (82.6%); most of the patients (56.5%) also presented decreased growth velocity. Hormonal evaluation at the onset of PST revealed: CDI (91.3%), growth hormone deficiency (GHD) (56.5%), hyperprolactinemia (39%), central hypothyroidism (34.8%), adrenal insufficiency (9%), precocious puberty (8.7%). The majority of the patients were diagnosed with germinoma (seventeen patients - 73.9%, one of them with teratoma and germinoma). Langerhans cell histiocytosis (LCH) was identified in three patients (multisystem LCH in two patients, and unifocal LCH in one patient). A single case of atypical teratoid rhabdoid tumor, suspected low-grade glioma (LGG) and lymphocytic infundibuloneurohypophysitis (LINH). The overall survival rate during the observational period was 87.0%.

CONCLUSIONS

The pituitary infundibulum presents a diagnostic imaging challenge because of its small size and protean spectrum of disease processes. Germinoma should be suspected in all children with PST, especially with CDI, even when neurological and ophthalmological symptoms are absent.

Outcome of endoscopic transcortical intraventricular biopsy of isolated thickened pituitary stalk lesions in children

OBJECTIVE

The purpose of this study was to investigate the efficacy and safety of endoscopic transcortical intraventricular biopsy in pediatric patients with isolated thickened pituitary stalk lesions.

METHODS

From 1994 to 2018, 16 pediatric patients (8 males and 8 females) underwent endoscopic transcortical intraventricular biopsy at a single institution to establish an accurate pathological diagnosis for appropriate treatment strategies.

RESULTS

Preoperatively, the median diameter of the pituitary stalks was 5.31 ± 1.67 mm (range 3.86-9.17 mm). Overall, the diagnostic yield at endoscopic intraventricular biopsy was 93.8%. Histopathological diagnosis included germinoma (n = 10, 62.5%), Langerhans cell histiocytosis (n = 4, 25%), pilocytic astrocytoma (n = 1, 6.3%), and pituicytoma (n = 1, 6.3%). Two patients developed new diabetes insipidus after the procedure, and 3 patients had new postoperative hypothyroidism. There were no postoperative neurological deficits in this series.

CONCLUSIONS

Neuroendoscopic biopsy via the transcortical intraventricular corridor was shown to be safe and to aid in a reliable histopathological diagnosis in the management of isolated pituitary stalk lesions in pediatric patients. It can be considered a minimally invasive alternative to open biopsy via transcranial or endonasal corridors.

An Infundibular Unidentified Object (IUO): a new pituitary stalk marker?

PURPOSE

Measurement of the pituitary stalk (PS) diameter does not always solve the issue of minimal PS thickening. A previously undescribed image is found at the infundibular level on high resolution thin section T2W MRI in a large number of normal individuals. We speculate that this image-whose exact origin is still unknown-may serve as a marker of the normal infundibulum.

METHODS

In the last 6 months, 350 consecutive adult patients suspected of sellar pathology or controlled after medical or surgical treatment prospectively underwent a pituitary MRI including a sagittal T2W high resolution sequence. One hundred twelwe patients presenting a pituitary mass with suprasellar extension or those whose PS was not entirely visible were excluded.

RESULTS

A short focal annular T2 hypointense thickening of the wall of the infundibular recess of the third ventricle, more pronounced anteriorly was found in 151/238 patients. Additionally, a more or less tiny ventral extension was demonstrated on sagittal T2W sequence in 105/151 patients. These images were not identified on T1W or on T1W gadolinium enhanced sequences. The ring-like infundibular thickening and/or its ventral extension were not identified in 87/238 patients; in 43/87 of these patients the PS was found severely stretched mainly in case of primary or secondary empty sella. If patients with empty sella were excluded, our finding was observed in 194/238 cases, i.e. in 82%.

CONCLUSIONS

A detailed appearance of the PS on T2W MRI is described for the first time. A previously unreported T2W hypointense annular focal image prolonged by a tiny spicular or nodular ventral bud is found at the lower part of the infundibulum in a majority of normal patients, but not if the PS is stretched such as in empty sella. This image has to be recognized as a normal anatomical landmark. The possible origin of this image is discussed but not totally elucidated. An ongoing research will demonstrate or not if this image may serve as a marker to improve the early diagnosis of PS lesions.

Management of children and young people with idiopathic pituitary stalk thickening, central diabetes insipidus, or both: a national clinical practice consensus guideline

Unexplained or idiopathic pituitary stalk thickening or central diabetes insipidus not only harbours rare occult malignancies in 40% of cases but can also reflect benign congenital defects. Between 2014 and 2019, a multidisciplinary, expert national guideline development group in the UK systematically developed a management flowchart and clinical practice guideline to inform specialist care and improve outcomes in children and young people (aged <19 years) with idiopathic pituitary stalk thickening, central diabetes insipidus, or both. All such cases of idiopathic pituitary stalk thickening and central diabetes insipidus require dynamic pituitary function testing, specialist pituitary imaging, measurement of serum β-human chorionic gonadotropin and alpha-fetoprotein concentrations, chest x-ray, abdominal ultrasonography, optometry, and skeletal survey for occult disease. Stalk thickening of 4 mm or more at the optic chiasm, 3 mm or more at pituitary insertion, or both, is potentially pathological, particularly if an endocrinopathy or visual impairment coexists. In this guideline, we define the role of surveillance, cerebrospinal fluid tumour markers, whole-body imaging, indications, timing and risks of stalk biopsy, and criteria for discharge. We encourage a registry of outcomes to validate the systematic approach described in this guideline and research to establish typical paediatric stalk sizes and the possible role of novel biomarkers, imaging techniques, or both, in diagnosis.

Cryptorchidism is a Useful Clue for Idiopathic Hypogonadotropic Hypogonadism in Pituitary Stalk Thickening

Pituitary stalk lesions can represent a wide range of pathologies. The exact cause is often unknown due to hesitancy to proceed with biopsy. We present a 16-year-old adolescent who presented with delayed puberty, short stature and bilateral cryptorchidism. He was found to have a thickened pituitary stalk of uncertain etiology with partial hypopituitarism (gonadotrophin and growth hormone deficiency) on further assessment. The presence of bilateral cryptorchidism and micropenis represents lack of “mini puberty,” a phenomenon of activation of the hypothalamic-pituitary-gonadal (HPG) axis in-utero or within the first few months of life.¹ These key clinical features have been useful to establish an early temporal relationship and suggest a congenital origin of disease. This enabled a more conservative approach of surveillance to be employed as opposed to invasive pathological examination with pituitary stalk biopsy.

Diversity of Pathological Conditions Affecting Pituitary Stalk

Pituitary stalk lesions (PSL) are a very rare pathology. The majority of conditions affecting the infundibulum do not present with clinically apparent symptoms, what makes the diagnosis difficult. The recognition might be also complicated by the non-specific and transient characteristics of hormonal insufficiencies. In our study, we retrospectively analysed demographic, biochemical, and clinical long-term data of 60 consecutive, unselected adult patients (34 women and 26 men) with PSL diagnosed in the Department of Endocrinology, Jagiellonian University in Krakow. The diagnosis of PSL were categorized as confirmed, probable, or undetermined in 26, 26 and 8 patients, accordingly. Given the possible aetiology congenital, inflammatory, and neoplastic stalk lesions were diagnosed in 17, 15 and 20 patients, accordingly. In eight cases the underlying pathology remained undetermined. The most common pituitary abnormality was gonadal insufficiency diagnosed in 50.8% of cases. Diabetes insipidus was detected in 23.3% of cases. In 5% of patients the pituitary function recovered partially over time. Stalk lesions were extensively discussed in the context of the current literature. Based on the published data and our own experience a diagnostic algorithm has been proposed to help physicians with the management of patients with this challenging condition.

A Case of Burnt-Out Langerhans Cell Histiocytosis Presenting as Postpartum Hypopituitarism

Objective

To evaluate the case of a woman who presented with central hypogonadism and diabetes insipidus and further developed a persistent cough leading to an unexpected diagnosis of burnt-out Langerhans cell histiocytosis (LCH).

Methods

Clinical and laboratory endocrine evaluation, magnetic resonance imaging, high-resolution computed tomography, and open-lung biopsy results are discussed.

Results

A 28-year-old woman presented at 10 months postpartum with polydipsia, polyuria, and amenorrhea for 3 months. Her results showed a prolactin level of 25 μg/L (reference,<23.5 μg/L), estrogen level of 91 pmol/L (reference, 110-180 pmol/L), follicle-stimulating hormone level of 6 IU/L (reference, 2-20 IU/L), and luteinizing hormone level of 6 IU/L (reference, 2-70 IU/L). A water-deprivation test found a sodium concentration of 148 mmol/L (reference, 135-145 mmol/L), serum osmolality of 310 mmol/kg (reference, 275-295 mmol/kg), and urine osmolality of 107 mmol/kg (reference, 50-1450 mmol/kg) that improved to 142 mEq/L, 295 mmol/kg, and 535 mmol/kg, respectively, after desmopressin administration. Gadolinium-enhanced pituitary magnetic resonance imaging demonstrated a markedly thickened stalk with uniform enhancement. Chest high-resolution computed tomography confirmed bilateral upper-zone cystic lung disease suggestive of either pulmonary lymphangioleiomyomatosis or LCH. Eventual histology showed CD1a-positive burnt-out LCH. This differentiation was crucial as pulmonary lymphangioleiomyomatosis exacerbates with estrogen therapy and pregnancy, which the patient was able to successfully pursue without disease exacerbation.

Conclusion

The patient's initial presentation was considered as lymphocytic hypophysitis, but subsequent cystic changes on high-resolution computed tomography led to a unifying definitive diagnosis of burnt-out LCH. This case highlights the importance of investigating for uncommon secondary causes of hypophysitis.

Symptomatic Pituitary Metastasis as Initial Manifestation of Renal Cell Carcinoma: Case Report and Review of Literature

Metastasis to the pituitary gland is extremely rare (∼2% of sellar masses). Clinical, biochemical, and radiologic characteristics of pituitary metastasis are poorly defined and can be difficult to diagnose before surgery. We present an unusual case with pituitary metastasis as the first manifestation of renal cell carcinoma (RCC). A 70-year-old male presented with acute onset of weakness, dizziness, diplopia, and progressively worsening headache. The initial CT head revealed a heterogeneous sellar mass measuring 2.8 × 1.9 × 1.7 cm. A follow-up MRI showed the sellar mass invading the right cavernous sinus. The presumptive diagnosis was a pituitary macroadenoma. Physical examination revealed bilateral 6th cranial nerve palsy and episodes of intermittent binocular horizontal diplopia. Hormonal testing noted possible secondary adrenal insufficiency (AM serum cortisol: 3.3 mcg/dL, ACTH: 8 pg/mL), secondary hypothyroidism (TSH: <0.01 mIU/L, FT4: 0.7 ng/dL), secondary hypogonadism (testosterone: 47 ng/dL, LH: 1.3 mIU/mL, and FSH: 2.3 mIU/mL), and elevated serum prolactin (prolactin: 56.8 ng/ml, normal: 4.0-15.2 ng/ml). IGF-1 level was normal at 110 ng/mL (47-192 ng/mL). The patient was discharged on levothyroxine and hydrocortisone therapy with plans for close surveillance. However, his condition worsened over the next three months, and he was subsequently readmitted with nausea, vomiting, and hypernatremia secondary to diabetes insipidus. Repeat MRI pituitary showed an interval increase in the size of the sellar mass with suprasellar extension and a new mass effect on the optic chiasm. The sellar mass was urgently resected via a trans-sphenoidal approach. The tumor was negative for neuroendocrine markers and pituitary hormone panel, ruling out the diagnosis of pituitary adenoma and triggered workup for metastatic renal cell carcinoma, clear cell type. The diagnosis of renal cell carcinoma was confirmed by the diffuse and strong staining for renal cell carcinoma markers (Pax-8, RCC-1, and CD10). A follow-up CT scan noted large right renal mass measuring 11 × 10 × 11 cm. The patient underwent a cytoreductive robotic right radical nephrectomy for WHO/ISUP histologic grade II clear cell RCC, stage pT2b pNX pM1. He subsequently received fractionated stereotactic radiotherapy to the pituitary gland. He is presently stable with no radiological evidence of progression or new intracranial disease on subsequent imaging. Pituitary metastasis most commonly occurs from breast, lung, or gastrointestinal tumors but also rarely from renal cell carcinoma. Biochemical findings such as panhypopituitarism, acute clinical signs such as headache, visual symptoms, and diabetes insipidus and interval increase in sellar mass in a short time interval should raise suspicion for sellar metastasis.

Diagnosis and Management of pituitary disease with focus on the role of Magnetic Resonance Imaging

Magnetic resonance (MR) imaging is an essential tool in the diagnosis and management of pituitary diseases, indispensable for making correct treatment decisions. Successful management and follow-up of pituitary pathology requires an understanding of the MR appearance of normal and abnormal structures in the sellar region. This review will describe the MR appearance of the normal and abnormal pituitary gland and proposes an algorithm for the management strategy of some of the most common abnormalities in or around the sella.

Pituitary Stalk Enlargement in Adults

Pathologies involving the pituitary stalk (PS) are generally revealed by the presence of diabetes insipidus. The availability of MRI provides a major diagnostic contribution by enabling the visualization of the site of the culprit lesion, especially when it is small. However, when only an enlarged PS is found, the etiological workup may be difficult, particularly because the biopsy of the stalk is difficult, harmful and often not contributive. The pathological proof of the etiology thus needs to be obtained indirectly. The aim of this article was to provide an accurate review of the literature about PS enlargement in adults describing the differences between the numerous etiologies involved and consequent different diagnostic approaches. The etiological diagnostic procedure begins with the search for possible other lesions suggestive of histiocytosis, sarcoidosis, tuberculosis or other etiologies elsewhere in the body that could be more easily biopsied. We usually perform neck, thorax, abdomen, and pelvis CT scan; positron emission tomography scan; bone scan; or other imaging methods when we suspect generalized lesions. Measurement of serum markers such as human chorionic gonadotropin, alpha-fetoprotein, angiotensin converting enzyme, and IgG4 may also be helpful. Obviously, in the presence of an underlying carcinoma (particularly breast or bronchopulmonary), one must first consider a metastasis located in the PS. In the case of an isolated PS enlargement, simple monitoring, without histological proof, can be proposed (by repeating MRI at 3-6 months) with the hypothesis of a germinoma (particularly in a teenager or a young adult) that, by increasing in size, necessitates a biopsy. In contrast, a spontaneous diminution of the lesion is suggestive of infundibulo-neurohypophysitis. We prefer not to initiate steroid therapy to monitor the spontaneous course when a watch-and-see attitude is preferred. However, in many cases, the etiological diagnosis remains uncertain, requiring either close monitoring of the lesion or, in exceptional situations, trying to obtain definitive pathological evidence by a biopsy, which, unfortunately, is in most cases performed by the transcranial route. If a simple surveillance is chosen, it has to be very prolonged (annual surveillance). Indeed, progression of histiocytosis or germinoma may be delayed.

Imaging in Short Stature and Bone Age Estimation

Short stature in children is a diagnostic challenge to the physician. Bone age assessment can be done using various methods. The causes of short stature are variable; often leading to a series of investigations. The endocrine conditions have typical imaging features. This chapter provides a short overview of the methods of bone age estimation, and imaging findings and algorithmic approach towards a child with short stature.

Etiological Spectrum and Pattern of Change in Pituitary Stalk Thickening: Experience in 321 Patients

OBJECTIVE

To summarize the etiologies of pituitary stalk thickening (PST) and the natural course of indistinguishable PST.

METHODS

Clinical information, including the symptoms at onset and laboratory, imaging, operative, pathological, and follow-up data, of patients with MRI-confirmed PST at Peking Union Medical College Hospital from January 2014 to May 2017 was collected and reviewed.

RESULTS

Of 321 eligible patients with PST, 28.3% were ≤18 years old. Central diabetes insipidus was the initial symptom in 68.8% of patients. At least one anterior pituitary hormone deficit was found in 57.6% of patients. The adjusted OR of panhypopituitarism associated with hypothalamus involvement was 7.3 (95% CI, 3.0 to 17.8; P < 0.001). Confirmed diagnoses were established in 137 patients (42.7%), including neoplasms (75.2%), inflammation (13.1%), and congenital anomalies (11.7%). Intracranial germ cell tumors (66.7%) were the leading cause among children, whereas histiocytoses (20.0%) and malignant metastases (14.7%) were the most common causes in adults. Thirty-eight patients with indistinguishable PST underwent a second MRI at a median time of 4.4 months. Spontaneous remission was observed in 17 of these patients (44.7%) after a median 8.5 months, with complete remission in 14 (36.8%) and partial remission in three (7.0%); five (13.2%) patients exhibited progression, and the remaining 16 (42.1%) stabilized.

CONCLUSION

PST is highly heterogeneous, and most confirmed cases are attributed to neoplasms. The etiological spectrum varies with age. Physicians must be familiar with the major differential diagnoses, necessary investigations, and follow-up. Biopsy is indicated when radiological progression and/or worsening of pituitary function is detected.

Age related signal changes of the pituitary stalk on thin-slice magnetic resonance imaging in infants

PURPOSE

Signals of some brain regions change along with development in T1-weighted imaging (T1WI) in infants. This study aimed to assess the association of the signal intensity of the pituitary stalk on thin-slice T1WI with infant age.

METHODS

This retrospective study was performed in 89 infants (gestational age [GA], 25-41 weeks; postmenstrual age [PMA], 36-46 weeks; chronological age [CA], 4-141 days) without intracranial abnormalities. The signal ratio of the pituitary stalk/pons on thin-slice T1WI was calculated, and its correlations with GA, PMA, and CA were assessed. Additionally, the signal ratio of the anterior pituitary gland/pons was calculated, and its correlation with that of the pituitary stalk was assessed. The signal intensity and distribution of the pituitary stalk were visually rated, and their correlations with GA, PMA, and CA were assessed.

RESULTS

The signal ratio of the pituitary stalk was significantly positively correlated with GA (P < 0.001) and negatively correlated with CA (P < 0.001), but was not correlated with PMA. Stepwise multiple regression revealed that CA was independently associated with the signal ratio of the pituitary stalk (P < 0.001). GA was significantly higher (P < 0.05) and CA was significantly lower (P < 0.05) in infants with a high signal intensity and wide distribution of high signal intensity of the pituitary stalk.

CONCLUSIONS

The signal intensity of the pituitary stalk on T1WI was negatively correlated with CA in infants, which might be related to postnatal changes in the pars tuberalis of the pituitary stalk after birth in infants.

PITUITARY STALK THICKENING IN A LARGE COHORT: TOWARD MORE ACCURATE PREDICTORS OF PITUITARY DYSFUNCTION AND ETIOLOGY

Objective: To summarize the characteristics of patients with pituitary stalk thickening, analyze the association between pituitary stalk width and hypopituitarism, and develop a diagnostic model to differentiate neoplastic and inflammatory origins. Methods: A total of 325 patients with pituitary stalk thickening in a tertiary teaching hospital between January 2012 and February 2018 were enrolled. Basic characteristics and hormonal status were evaluated. Indicators to predict etiology in patients with histologic diagnoses were analyzed. Results: Of the 325 patients, 62.5% were female. Deficiency in gonadotropin was most common, followed by corticotropin, growth hormone, and thyrotropin. The increase in pituitary stalk width was associated with a risk of central diabetes insipidus (odds ratio [OR], 3.57; P<.001) and with a combination of central diabetes insipidus and anterior pituitary deficiency (OR, 2.28; P = .029). The cut-off pituitary stalk width of 4.75 mm had a sensitivity of 69.2% and a specificity of 71.4% for the presence of central diabetes insipidus together with anterior pituitary deficiency. Six indicators (central diabetes insipidus, pattern of pituitary stalk thickening, pituitary stalk width, neutrophilic granulocyte percentage, serum sodium level, and gender) were used to develop a model having an accuracy of 95.7% to differentiate neoplastic from inflammatory causes. Conclusion: Pituitary stalk width could indicate the presence of anterior pituitary dysfunction, especially in central diabetes insipidus patients. With the use of a diagnostic model, the neoplastic and inflammatory causes of pituitary stalk thickening could be preliminarily differentiated. Abbreviations: APD = anterior pituitary dysfunction; AUC = area under the curve; CDI = central diabetes insipidus; GH = growth hormone; MRI = magnetic resonance imaging; OR = odd ratio; PHBS = posterior hypophyseal bright spots; PST = pituitary stalk thickening; PSW = pituitary stalk width.

A UNIQUE CASE OF CENTRAL HYPOPITUITARISM AND CENTRAL DIABETES INSIPIDUS CAUSED BY DIFFUSE LARGE B-CELL LYMPHOMA

OBJECTIVE

To present the case of a 39-year-old male admitted to the hospital with diabetes insipidus as a sequela of a previously undiagnosed diffuse large B-cell lymphoma. This case is unique, as the patient's disease was determined to be an infiltrative malignancy affecting the pituitary infundibular stalk, resulting in multifocal pituitary dysfunction.

METHODS

Case report.

RESULTS

Initially presenting with gastrointestinal bleed, later discovered to be from tumor infiltration of gastric vessels, diagnosis of lymphoma was made when gastrectomy became necessary for hemostasis. Subsequent hypernatremia on basic laboratory studies led to further investigation and revealed central diabetes insipidus. Magnetic resonance imaging of the pituitary was performed, showing thickening of the infundibular stalk. Additional endocrine evaluation revealed central hypothyroidism and central adrenal insufficiency.

CONCLUSION

Radiologic findings of thickened pituitary infundibulum can support the diagnosis of central diabetes insipidus when additional symptoms are present. Central diabetes insipidus due to lymphomatous infundibular stalk infiltration is an uncommon presentation of endocrine deficiency as well as malignancy; this case demonstrates the management of a critically ill patient with central hypopituitarism due to diffuse B-cell lymphoma.

Single center study of 53 consecutive patients with pituitary stalk lesions

BACKGROUND

The etiological spectrum of pituitary stalk lesions (PSL) is wide and yet specific compared to the other diseases of the sellar and suprasellar region. Because of the pituitary stalk's (PS) critical location and role, biopsies of these lesions are rarely performed, and their underlying pathology is often a conundrum for clinicians. A pituitary MRI in association with a clinical context can facilitate their diagnosis.

AIM

To present the various causes of PSL-their clinical, hormonal, histopathological, and MRI characteristics in order to gain better insight into this pathology.

METHOD

A retrospective observational study consisting of 53 consecutive patients with PSL of the mean age 32 ± 4.2 years (range 6-67), conducted at the Department for Neuroendocrinology, Clinical Center of Serbia 2010-2018.

RESULTS

Congenital malformations were the most common cause of PSL in 25 of 53 patients (47.1%), followed by inflammatory (9/53; 16.9%) and neoplastic lesions (9/53; 16.9%). The exact cause of PSL was established in 31 (58.4%) patients, of whom 23 were with congenital PS abnormalities and 8 with histopathology of PSL (7 neoplastic and 1 Langerhans Cell Hystiocytosis). A probable diagnosis of PSL was stated in 12 patients (22.6%): 6 with lymphocytic panhypophysitis, while Rathke cleft cyst, tuberculosis, dissemination of malignancy in PS were each diagnosed in 2 patients. In 10 patients (18.8%), the etiology of PSL remained unknown.

CONCLUSION

Due to the inability of establishing an exact diagnosis, the management and prognosis of PSL are difficult in many patients. By presenting a wide array of causes implicated in this condition, we believe that our study can aid clinicians in the challenging cases of this pathology.

Cancer immunotherapy-associated hypophysitis

Side effects of immune checkpoint blockade are often said to be infrequent and usually mild. The uniqueness of endocrine immune-related adverse events is their non-reversibility, with incidence and prevalence destined to increase in the coming years, particularly if immunotherapy is used at earlier stages of neoplastic disease. Immune-related hypophysitis is one of these observed endocrine adverse events. It is often difficult to diagnose, sometimes occurring without specific symptoms. It can lead to irreversibly altered functioning of diverse endocrine glands. Radiographically, the differential diagnosis of hypophysitis includes pituitary apoplexy and primary and secondary neoplastic lesions. Immune-related hypophysitis is most common with single-agent anti-CTLA-4, followed by the combination of anti-CTLA-4 and anti-PD-1, while occurs infrequently when anti-PD-1 or anti-PD-L1 agents are administered alone. Hypophysitis with immune checkpoint blockade requires early recognition, diagnosis, and treatment. Patients can present with headache, visual disturbances or other endocrine-related syndromes or they can be asymptomatic. The manifestation of symptoms should prompt blood analysis and magnetic resonance imaging of the brain. Imaging is important to exclude secondary meningeal or parenchymal lesions. Management should include discontinuation of the immune checkpoint blockade, initiation of corticosteroid therapy and eventually hormone replacement therapy. Hypophysitis impacts treatment of the disease and usually requires long-term management of this irreversible side effect. A multidisciplinary team approach is merited to insure the correct diagnosis and management of immune-related hypophysitis.

Neuro-radiological features can predict hypopituitarism in primary autoimmune hypophysitis

Primary autoimmune hypophysitis (PAH) is considered an underdiagnosed disease, due to the difficulty in reaching a definitive diagnosis. PAH clinical diagnosis remains an exclusion diagnosis. We aimed to correlate PAH neuro-radiological signs to endocrine features and evaluate their prognostic role. 24 PAH cases were enrolled and classified according to neuro-radiological signs: in 12 adeno-hypophysitis (AHs), 8 infundibulo-neuro-hypophysitis (INHs) and 4 pan-hypophysitis (PHs). Secondary hypogonadism developed more frequently in INHs as compared to AHs (54.5% vs. 27.3%, p = 0.05), without no difference with PHs (p = 0.6). Diabetes insipidus occurred more frequently in INHs cases (72.7%, p < 0.001) and in PHs cases (27.3%, p = 0.007), as compared to AHs cases (0%). Similarly, all cases of GHD occurred in INHs (100%) as compared to AHs (0%, p < 0.001) and PHs (0%, p < 0.001). The pituitary stalk (PS) showed a pseudo-triangular shape (larger at the optical chiasma) in INHs and a pseudo-cylindrical shape (larger both at the optical chiasma and at the pituitary insertion) in PHs. The PS pseudo-triangular shape correlated to the occurrence of GHD and diabetes insipidus (p < 0.001/p = 0.03). At the 1-year follow-up, improvement of baseline radiological features positively correlated with the loss of the neuro-pituitary "bright spot" on T1-weighted images (OR 0.16; 95% CI 0.03-0.9 p = 0.02) and with a PS diameter at the optical chiasma level larger than 4.1 mm (AUC 0.97, sensibility 80%, specificity 100%, OR 6; 95% CI1.1-28.8, p = 0.01) Our data suggest that neuro-radiological PAH classification in PH, AH and INH can predict pituitary dysfunction and that some neuro-radiological features, such as the pituitary stalk diameter and the loss of the neuro-pituitary bright spot on T1w images can play a role as a positive prognostic marker of the radiological hypophysitis outcome.

Twenty-Five Diagnoses on Midline Images of the Brain: From Fetus to Child to Adult

Midsagittal images of the brain provide a wealth of anatomic information and may show abnormalities that are pathognomonic for particular diagnoses. Using an anatomy-based approach, the authors identify pertinent anatomic structures to serve as a checklist when evaluating these structures. Subregions evaluated include the corpus callosum, pituitary gland and sellar region, pineal gland and pineal region, brainstem, and cerebellum. The authors present 25 conditions with characteristic identifiable abnormalities at midsagittal imaging. Midsagittal views from multiple imaging modalities are shown, including computed tomography, ultrasonography, and magnetic resonance (MR) imaging. Standard MR imaging sequences are shown, as well as fetal MR and sagittal diffusion-weighted images. To demonstrate these conditions, fetal, neonatal, childhood, adolescent, and young adulthood images are reviewed. The differentiation of normal variants is guided by the understanding of anatomy and pathology. When a specific diagnosis is not possible, the authors present information to evaluate differential considerations and discuss when follow-up imaging may be indicated. The authors hope each case will clarify a pertinent differential diagnosis, appropriately guide patient management, and improve understanding of normal anatomy and identification of pathologic entities. It is in these hopes that the authors have presented a checklist of pertinent anatomy and pathologic entities that can build on existing search patterns. Improved confidence and accuracy in the evaluation of midsagittal images will benefit physicians and patients. ^©RSNA, 2018.

Joint approach based on clinical and imaging features to distinguish non-neoplastic from neoplastic pituitary stalk lesions

Purpose

Distinguishing non-neoplastic pituitary stalk lesions (non-NPSLs) from neoplastic pituitary stalk lesions (NPSLs) is a major concern in guiding treatment for a thickened pituitary stalk. Our study aimed to aid provide preoperative diagnostic assistance by combining clinical and magnetic resonance imaging (MRI) findings to distinguish non-NPSLs from NPSLs.

Materials and methods

We recruited 158 patients with thickened pituitary stalk lesions visible on MRI. Laboratory findings included hypopituitarism, diabetes insipidus (DI), and hyperprolactinemia. MR images were assessed for anterior–posterior thickness (mm), diffuse pituitary stalk thickening, cystic changes, a high T1 signal, and glandular or extrasellar involvement. A diagnostic model was developed using a recursive partitioning logistic regression analysis. The model was validated in an independent dataset comprising 63 patients, and its diagnostic performance was compared with that of the original radiological reports.

Results

A univariate analysis found significant associations of DI (P = 0.006), absence of extrasellar involvement (P = 0.002), and lower stalk thickness (P = 0.031) with non-NPSLs. A diagnostic model was created using the following parameters (in order of priority): 1) lack of extrasellar involvement, 2) stalk thickness < 5.3 mm, and 3) presence of DI. The diagnostic performance (area under the curve; AUC) of this model in the independent set was 0.813, representing a significant improvement over the original radiological reports (AUC: 0.713, P = 0.029).

Conclusion

The joint diagnostic approach based on clinical and imaging-based factors robustly distinguished non-NPSLs from NPSLs. This approach could guide treatment strategies and prevent unnecessary surgery in patients with non-NPSL.

Looking beyond the Sella: Suprasellar Infundibular Prolactinoma

This is a case report of a 24-year-old female who presented with galactorrhoea and elevated serum prolactin levels of 150 ng/mL. The intrasellar pituitary gland demonstrated normal morphology and characteristic enhancement. The pituitary stalk was thickened and revealed a non-enhancing lesion on dynamic contrast imaging, which was interpreted as a functioning microadenoma. The patient exhibited significant clinical improvement after initiation of therapy with a dopamine agonist, Cabergoline.

Pituitary stalk thickening: the role of an innovative MRI imaging analysis which may assist in determining clinical management

CONTEXT

Disease processes that affect the pituitary stalk are broad; the diagnosis and management of these lesions remains unclear.

OBJECTIVE

The aim was to assess the clinical, biochemical and histopathological characteristics of pituitary stalk lesions and their association with specific MRI features in order to provide diagnostic and prognostic guidance.

DESIGN AND METHODS

Retrospective observational study of 36 patients (mean age 37years, range: 4-83) with pituitary stalk thickening evaluated at a university hospital in Oxford, UK, 2007-2015. We reviewed morphology, signal intensity, enhancement and texture appearance at MRI (evaluated with the ImageJ programme), along with clinical, biochemical, histopathological and long-term follow-up data.

RESULTS

Diagnosis was considered certain for 22 patients: 46% neoplastic, 32% inflammatory and 22% congenital lesions. In the remaining 14 patients, a diagnosis of a non-neoplastic disorder was assumed on the basis of long-term follow-up (mean 41.3months, range: 12-84). Diabetes insipidus and headache were common features in 47 and 42% at presentation, with secondary hypogonadism the most frequent anterior pituitary defect. Neoplasia was suggested on size criteria or progression with 30% sensitivity. However, textural analysis of MRI scans revealed a significant correlation between the tumour pathology and pituitary stalk heterogeneity in pre- and post-gadolinium T1-weighted images (sensitivity: 88.9%, specificity: 91.7%).

CONCLUSIONS

New techniques of MRI imaging analysis may identify clinically significant neoplastic lesions, thus directing future therapy. We propose possible textural heterogeneity criteria of the pituitary stalk on pre- and post-gadolinium T1 images with the aim of differentiating between neoplastic and non-neoplastic lesions with a high degree of accuracy.

Pituitary stalk lesions: systematic review and clinical guidance

The spectrum of pituitary stalk (PS) pathology is vast, presenting a diagnostic challenge. Published large series of PS lesions demonstrate neoplastic conditions are most frequent, followed by inflammatory, infectious and congenital diseases. Inflammatory pathologies however, account for the majority of PS lesions in published small case series and case reports. Physicians must be familiar with the major differential diagnoses and necessary investigations. A comprehensive history and thorough clinical examination is critical. Although magnetic resonance imaging of the PS in disease is nonspecific, associated intracranial features may narrow the differential diagnosis. Initial investigations include basic pathology and computer tomography imaging of the neck, chest, abdomen and pelvis. Further investigations should be guided by the clinical context. PS biopsy should be considered when a diagnosis is regarded essential in centres where an experienced neurosurgeon is available. Treatment is dependent on the underlying disease process and may necessitate pituitary hormone replacement.

Magnetic resonance imaging of sellar and juxtasellar abnormalities in the paediatric population: an imaging review

The sellar and juxtasellar regions in the paediatric population are complex both anatomically and pathologically, with magnetic resonance imaging (MRI) being the "gold standard" imaging modality due to the high contrast of detail. Assessment requires a detailed understanding of the anatomy, embryology, pathophysiology and normal signal characteristics of the pituitary gland and surrounding structures in order to appropriately characterise abnormalities. This article aims to provide an overview of the imaging characteristics of developmental/congenital and acquired disease processes which affect the sellar and juxtasellar region in the paediatric population. Main Messages • The sellar region is anatomically complex and covers a wide pathology spectrum. • MRI is the key imaging modality to assess sellar and juxtasellar pathology. • Numerous developmental anomalies may not be discovered until adulthood. • Knowledge of pathology alerts and guides the clinician towards appropriate management.

Hypothalamic type of hypopituitarism and central diabetes insipidus probably linked to Rathke's cleft cyst

A 73-year-old woman was admitted due to weight loss and generalized malaise. The basal levels of all the anterior pituitary hormones, except for prolactin, were reduced. However, they were all elevated in response to exogenous hypothalamic hormones. After starting hydrocortisone replacement, the patient had polyuria of >5,000 mL/day. T1-weighted MRI depicted a low signal of an oval mass in the sella turcica and an iso-intense signal of another mass at the pituitary stalk. These findings indicate a hypothalamic type of hypopituitarism and masked central diabetes insipidus which possibly derived from the atypical occupation of Rathke's cleft cyst at the pituitary stalk.

Clinical and radiological features of pituitary stalk lesions in children and adolescents

PURPOSE

The diagnosis of pituitary stalk lesion has been based on clinical feature, radiologic assessment for its critical location and role. This study aimed to investigate clinical symptoms, endocrine disturbance, magnetic resonance imaging (MRI) findings of pituitary stalk lesions in children and adolescents and to evaluate differences between neoplastic lesions with the others.

METHODS

We performed a retrospective review of patients under 18 years old with pituitary stalk lesions diagnosed at the Seoul National University Children's Hospital between 2000 and 2013, by a text search for head MRI reports by using 'pituitary stalk', 'infundibulum', and 'infundibular stalk', as keywords.

RESULTS

For the 76 patients, sixteen patients (21.1%) had congenital lesions, and 52 (68.4%) had neoplasms. No inflammatory lesions were found. Diabetes insipidus (DI) was the most common endocrine defect, diagnosed in 38 patients (50%). There was male predominance especially in neoplastic group. Thickened pituitary stalk was, but enhancement of lesion was not, associated with neoplasm. DI was more prevalent in neoplastic stalk lesions. Anterior pituitary dysfunction such as growth hormone and adrenocorticotropic hormone deficiencies were less prevalent in neoplastic lesions of pituitary stalk.

CONCLUSION

In conclusion, the etiology of pituitary stalk lesions in children and adolescents is diverse and different from that in adults. Neoplastic pituitary stalk lesions can be differentiated from nonneoplastic lesions by systemic evaluation of clinical, hormonal, radiological findings.

Pretreatment diagnosis of suprasellar papillary craniopharyngioma and germ cell tumors of adult patients

BACKGROUND AND PURPOSE

Suprasellar papillary craniopharyngiomas and germ cell tumors in adults share some clinical and imaging similarities but have different therapeutic strategies and outcomes. This study aimed to evaluate the pretreatment diagnosis of these 2 tumors to improve the therapeutic outcome.

MATERIALS AND METHODS

We retrospectively enrolled 18 adults with papillary craniopharyngiomas and 17 with germ cell tumors. The MR imaging findings were evaluated, including signal change and anatomic extension. The medical records were reviewed to collect clinical findings, management, and outcomes.

RESULTS

The clinical findings of papillary craniopharyngiomas versus germ cell tumors were as follows: age: 46 ± 13.9 years versus 23 ± 7.1 years (P < .0001); diabetes insipidus: 2/18 (11%) versus 11/17 (65%) (P = .001); recurrence 13/16 (81%) versus 4/17 (24%) (P = .0031). The MR imaging findings of papillary craniopharyngiomas versus germ cell tumors were as follows—pituitary stalk thickening: 1.6 ± 0.4 mm versus 5.4 ± 4.2 mm (P < .0001); vertical infundibular extension: 1/18 (6%) versus 16/17 (94%) (P < .0001); sagittal spheric shape: 17/18 (94%) versus 1/17 (6%) (P < .0001); diffusion restriction: 1/17 (6%) versus 8/12 (67%) (P = .0009).

CONCLUSIONS

Younger age, diabetes insipidus, MR imaging characteristics of restricted diffusion, and vertical infundibular extension favor the diagnosis of germ cell tumors. Spheric shape without infundibular infiltration provides clues to papillary craniopharyngiomas, which originate from the pars tuberalis and are located outside the third ventricle. We suggest that suprasellar germ cell tumor is possibly an intraventricular lesion. Appropriate treatment planning can be initiated according to the diagnosis and anatomic location.

A 23-year-old female with a mixed germ cell tumor of the pituitary infundibulum: the challenge of differentiating neoplasm from lymphocytic infundibuloneurohypophysitis-a case report and literature review

The pathologic spectrum of diseases that infiltrate the pituitary infundibulum includes a broad variety of clinical entities. There are significant differences in the prevalence of these etiologies depending on the age of presentation. Lymphocytic infundibuloneurohypophysitis (LINH) predominates over other causes of infundibular disease in adults over age 21. Differentiating LINH from other causes of infundibular disease can be difficult because the various etiologies often have similar clinical presentations and radiologic imaging characteristics. We report the first case in an adult of a mixed germ cell tumor comprised of germinoma and embryonal cell carcinoma infiltrating the pituitary infundibulum. In our case, a 23-year-old female was initially misdiagnosed as having LINH. She presented with panhypopituitarism and diabetes insipidus, which is the most common initial presentation in both entities. The two diagnoses are difficult to distinguish based on MRI imaging, CSF findings, and histopathological examination. Our case demonstrates the need for close follow-up of patients with isolated lesions of the pituitary infundibulum and reinforces the need for biopsy of an infundibular lesion when progression of disease is demonstrated. In our case, biopsy with comprehensive immunohistochemical staining was the sole means of making a definitive diagnosis.

Predictors of neoplastic disease in children with isolated pituitary stalk thickening

BACKGROUND

The significance of pituitary stalk thickening (PST) on magnetic resonance imaging (MRI) is often unclear. We evaluated presenting symptoms, MRI findings, clinical course, and outcome predictors of patients with PST.

PROCEDURE

We used a computerized search of the medical record from 1995 to 2008 to identify patients with PST without pituitary mass on MRI. Baseline and follow-up MRIs were reviewed in a blinded fashion. Relevant clinical data were abstracted.

RESULTS

69 patients with reported PST and adequate imaging for review were identified; 42 met study criteria. Median age at first abnormal MRI was 13.6 years (range: 0.8-19.7); 43% were male. Median follow-up was 3.4 years (range 0-12.8). Patients with diabetes insipidus (DI) were significantly more likely to have a neoplastic process than those without (P = 0.0008). Of 16 patients with DI, 8 (50%) had a neoplastic process, including germ cell tumor (n = 4), Langerhans cell histiocytosis (n = 3), and lymphoma (n = 1). Among patients with DI, 7 (44%) also developed anterior pituitary hormone dysfunction (APD), either at presentation or on pre-biopsy follow-up, including 6/8 patients with stalk neoplasm and only 1/8 patients with non-neoplastic PST (P = 0.04). Twenty-six patients presented without DI; none was found to have neoplasm of the stalk except one patient with craniopharyngioma. Progression of PST on follow-up imaging was significantly associated with a subsequent neoplastic diagnosis (P = 0.04).

CONCLUSION

Patients with PST without DI are unlikely to have a neoplastic process. Among patients with DI, APD or progressive stalk increase over time are predictive of neoplasia.

Latency of intracranial germ cell tumors and diagnosis delay

BACKGROUND

Intracranial germ cell tumors (GCTs) frequently take an insidious clinical course before diagnosis. To date, clinical latency has been discussed in the context of germinoma in the suprasellar area and basal ganglia.

OBJECTIVE

In this study, we classified the clinical latency of intracranial GCTs into three categories and described their characteristics in order to understand the full spectrum of the phenomenon.

METHODS

In a cohort of 181 patients with intracranial GCTs, 17 patients had a delayed diagnosis of more than 3 months (90 days) from the initial brain magnetic resonance imaging to the definitive GCT diagnosis. Clinical records and radiological data of the patients were reviewed.

RESULTS

The patients with a delayed diagnosis were categorized into three groups according to their tumor location: suprasellar (nine patients), basal ganglia (six patients), and pineal (two patients). Initial symptomatology corresponded with the tumor location: central diabetes insipidus for the suprasellar group, hemiparesis for the basal ganglia group, and precocious puberty for the pineal group. The overall survival of patients with germinoma and delayed diagnosis was significantly shorter than that of patients who were diagnosed within 3 months (P = 0.002).

CONCLUSIONS

Clinical latency and delayed diagnosis are not restricted to germinomas in the suprasellar area and basal ganglia; they are canonical features of intracranial GCTs including pineal non-germinomatous GCTs. Early detection and proactive diagnosis of these tumors are required because diagnosis delay may negatively influence patient survival.

Septo-optic dysplasia: fitting the pieces together

A 7-year-old boy was admitted for a general tonic-clonic seizure with severe hypoglycaemia (1.39 mmol/l). His medical history was remarkable for a congenital left eye strabismus, unilateral cryptorchidism and three previous episodes of hypoglycaemic seizures with inconclusive metabolical and neurological investigations. Physical examination revealed a hoarse tone voice, dry skin, cold extremities and height in the third percentile (target height between 50th and 85th percentile). Left wrist radiography revealed a bone age of 4.5 years ±6 months Laboratory studies confirmed growth hormone deficiency and central hypothyroidism. The brain MRI showed an ectopic neurohypophysis. Neuroophthalmology investigation revealed left optic nerve hypoplasia and septo-optic dysplasia was then diagnosed. Thyroid and recombinant growth hormone replacement were started showing clinical improvement. A detailed clinical history and a careful physical examination in children presenting with multiple clinical signs of hypopituitarism may lead to a timely diagnosis, avoiding clinical morbidity associated to untreated hormonal abnormalities.

Pituitary stalk lesions: the Mayo Clinic experience

CONTEXT

Pituitary stalk lesions have various etiologies, often not clinically apparent. Pathological samples from these lesions are rarely obtained, because of the critical location and function of the hypophyseal stalk.

OBJECTIVES

The purpose of this study was to characterize the etiological spectrum of pituitary stalk lesions seen at Mayo Clinic Rochester over 20 years and to determine whether specific magnetic resonance imaging (MRI) characteristics could provide clinician guidance with regard to the etiology of infundibular lesions.

DESIGN

A retrospective review of patients with pituitary stalk lesions seen at Mayo Clinic Rochester between 1987 and 2006 was conducted. Demographic, clinical presentation, imaging, laboratory, operative, and pathology data were reviewed and are reported using descriptive statistics.

RESULTS

Of the 152 pituitary stalk lesions included, 49 (32%) were neoplastic, 30 (20%) were inflammatory, 13 (9%) were congenital anomalies, and 60 (39%) were of unclear etiology. Diabetes insipidus was diagnosed in 43 (28%) of the 152 patients, and 49 (32%) patients had at least one anterior pituitary hormone deficit. Secondary hypogonadism was the most common endocrine deficiency. Eleven of 13 congenital lesions were round in appearance and 5 of 7 patients with neurosarcoidosis confirmed by pathology had a uniformly thickened pituitary stalk on MRI. There were no statistically significant correlations between hypopituitarism and the pattern of enhancement or size of the lesion.

CONCLUSIONS

Findings on MRI remain key in guiding the diagnosis of pituitary stalk lesions, particularly when used in conjunction with other clinical clues. There are no good imaging predictors for hypopituitarism, making clinical evaluation of all patients with pituitary stalk lesions crucial.

Endoscopic biopsies of lesions associated with a thickened pituitary stalk

BACKGROUND

Lesions associated with a thickened pituitary stalk (TPS lesions) revealed by magnetic resonance imaging have a diverse pathology. Accordingly, for clinical decision-making, it is necessary to make a diagnosis based on histopathological examination of the TPS lesions. The objectives of this study were to review endoscopic biopsies of TPS lesions and to assess the surgical strategy for treating these lesions.

METHODS

Eleven patients (four males and seven females) aged from 6 to 75 years underwent endoscopic biopsy of a TPS lesion between 2006 and 2011 at University of Niigata. The relationships of the extent of lesions with surgical approaches were retrospectively examined.

RESULTS

Among the 11 patients, a biopsy was performed via an endoscopic transsphenoidal approach for five with intrasellar lesions; via an endoscopic extended transsphenoidal approach for two with localized TPS lesions; and via an endoscopic intraventricular approach for four with the lesion protruding from the infundibulum. Histopathological examinations of all the lesions confirmed diagnoses of germinoma in four patients, hypophysitis in three, Langerhans cell histiocytosis in two, craniopharyngioma in one, and cancer metastasis in one. None of the 11 patients had further deterioration of pituitary function postoperatively.

CONCLUSIONS

Endoscopic biopsy of TPS lesions is a less invasive alternative to open biopsy requiring transcranial surgery. The endoscopic transsphenoidal approach is most suitable for biopsies of TPS lesions associated with intrasellar lesions. Otherwise, the endoscopic intraventricular approach seems reasonable for intraventricular lesions protruding from the infundibulum, and the endoscopic extended transsphenoidal approach appears appropriate for localized TPS lesions.

Imaging of the pituitary

In the appropriate clinical setting of pituitary hyperfunction or hypofunction, visual field deficit, or cranial nerve palsy, imaging of the pituitary is necessary. This article reviews the normal appearance of the pituitary and its surroundings, emphasizing magnetic resonance imaging. Typical and variant appearances of pituitary pathology are discussed. Because growth of adenoma into surrounding structures is important to surgical management, cavernous sinus invasion and suprasellar spread as well as adenoma mimics are illustrated. Typical examples of pituitary dysfunction from other entities that secondarily affect the gland, hypophysis, or third ventricle are discussed. Some common errors of interpretation are listed.

Pituitary stalk craniopharyngioma

Craniopharyngiomas are benign but aggressive neoplasms arising along the craniopharyngeal duct. It is frequently located in the suprasellar region. Primarily pituitary stalk craniopharyngioma is unusual and uncommonly early diagnosed, before it enlarges and extends to supra or parasselar region. This unusual location and the small size pose therapeutic dilemmas, since it has the ability to grow larger. Currently, no consensus exists regarding the optimal management. The authors have recommended complete resection.

A patient with diabetes insipidus, anterior hypopituitarism and pituitary stalk thickening

BACKGROUND

A 42-year-old woman presented to the neuroendocrine unit of a hospital with recent-onset polydipsia, polyuria and oligomenorrhea. She had no visual symptoms, head injury or history of malignancy.

INVESTIGATIONS

Measurement of serum sodium and osmolality (as well as urine osmolality) after water deprivation, both before and after desmopressin administration. Measurement of basal serum concentrations of pituitary hormones, insulin-like growth factor 1 and thyroid hormone, cosyntropin stimulation testing of adrenal function, and growth-hormone-releasing hormone-arginine stimulation testing. MRI of the pituitary, CT of the chest and abdomen, skeletal surveys, analyses of cerebrospinal fluid, serology and histologic examination of an excised, painful submandibular salivary gland.

DIAGNOSIS

Central diabetes insipidus and anterior hypopituitarism secondary to Langerhans cell histiocytosis.

MANAGEMENT

Replacement therapies, including desmopressin, levothyroxine, cyclic estrogen with medroxyprogesterone, and growth hormone. The stalk lesion remained stable after 7 years without specific therapy.

Normal pituitary stalk: high-resolution MR imaging at 3T

BACKGROUND AND PURPOSE

Knowing the normal imaging appearance of the pituitary stalk is important for the diagnosis of pituitary infundibular lesions, and more accurate assessment of the stalk may be possible at 3T than at 1.5T. Our purpose was to evaluate the normal pituitary stalk by use of high-resolution MR imaging at 3T.

MATERIALS AND METHODS

Sagittal MPRAGE images and high-resolution oblique-axial T2-weighted images of the pituitary stalk were acquired in 29 healthy volunteers (16 men and 13 women; mean age, 28 years; age range, 21-43 years) at 3T. The diameter and length of the pituitary stalk and the depth of the infundibular recess were measured. Signal intensity of the stalk was visually evaluated on T2-weighted images.

RESULTS

The AP and transverse diameters of the pituitary stalk were 2.32 +/- 0.39 mm and 2.16 +/- 0.37 mm at the pituitary insertion, respectively, and 3.25 +/- 0.43 mm and 3.35 +/- 0.44 mm at the level of the optic chiasm. No significant differences were observed between the AP and transverse diameters at each level. The length of the stalk was 5.91 +/- 1.24 mm, and the depth of the infundibular recess was 4.69 +/- 0.87 mm. The stalk showed central hyperintensity with a peripheral rim of isointensity in 20 subjects (69%) and homogeneous isointensity in 9 subjects (31%).

CONCLUSIONS

The data of the current study can serve as standard measurements of the normal pituitary stalk. The central hyperintensity and peripheral rim may represent the infundibular stem and pars tuberalis, respectively.

ENDOSCOPIC INTRAVENTRICULAR BIOPSY OF INFUNDIBULAR LANGERHANS CELL HISTIOCYTOSIS

OBJECTIVE

Surgical biopsy of isolated infundibular lesions is indicated in patients who are symptomatic or whose imaging suggests a treatable lesion. Early therapy can prevent irreversible neurological or endocrinological damage and, potentially, metastasis. These considerations justify the small risk associated with surgery.

CLINICAL PRESENTATION

A 5-year-old boy presented with diabetes insipidus and an enhancing lesion of the pituitary stalk without evidence of extracranial disease.

INTERVENTION

The lesion was biopsied via an endoscopic intraventricular approach without complications. Pathological examination revealed Langerhans cell histiocytosis.

CONCLUSION

Endoscopic intraventricular biopsy can be considered as a less invasive alternative to craniotomy in patients with infundibular lesions protruding superiorly into the third ventricle.

Pituitary stalk lesions

PURPOSE OF REVIEW

To describe the diverse causes of pituitary stalk lesions, their diagnosis, and treatment.

RECENT FINDINGS

Pathology of the pituitary stalk is often distinct from disease processes that affect the hypothalamus and/or pituitary. Pituitary stalk lesions fall into one of three categories: congenital, inflammatory/infectious, and neoplastic lesions.

SUMMARY

Stalk thickening may be found incidentally or when evaluating pituitary functional abnormalities. The precise cause must be looked for to enable the proper form of therapy of the underlying process. Hormone replacement is often also necessary.