Clinical review: Pituitary carcinoma: difficult diagnosis and treatment

A case of aggressive pituitary neuroendocrine tumour with extremely rapid progression: possible diagnostic value of TERT promoter methylation

Most pituitary adenoma/neuroendocrine tumours (PitNET) are histologically benign and grow slowly; however, a subset of these tumours exhibit a more aggressive clinical course characterized by local invasiveness and early recurrence. These high-risk PitNETs often require multiple surgeries and radiation over several years and may eventually acquire carcinomatous characteristics, such as metastasis in some cases. Herein, we report a rare case of PitNET causing oculomotor paresis with extremely rapid recurrence only 3 months after initial surgery, followed by lethal liver metastasis. Preoperative magnetic resonance imaging and intraoperative findings were consistent with typical PitNETs, other than moderate invasion of the cavernous sinus. Pathological examination of the specimen obtained from the initial transsphenoidal surgery revealed increased mitosis and elevated rates of cells positive for Ki-67 and p53. Based on the immunohistochemical assessment for transcription factors and pituitary hormones, the diagnosis was determined to be a silent sparsely granulated corticotroph PitNET with focal malignant transformation. Aggressive features represented by Ki-67 and p53 positivity were more robust in recurrent and metastatic specimens, but hormone immunostaining was decreased. Epigenetic analysis revealed methylation of the telomerase reverse transcriptase (TERT) promoter in the tumour, resulting in TERT upregulation. Despite extensive research, markers for distinguishing extremely aggressive PitNETs have not been determined. Although further analysis is needed, our case demonstrates the possible usefulness of assessing TERT promoter methylation status in the stratification of recurrence risk in extremely high-risk variants of PitNET.

Spontaneous regression of paediatric pituitary lesions-report of 2 cases and literature review

OBJECTIVE

Pituitary lesions are rare in the pediatric population. They consist of a heterogenous group of neoplasms including pituitary adenomas (PA) and Rathke cleft cysts (RCC). Their natural history, management strategies, and long-term outcomes are mostly extrapolated from adult experience. Neurosurgical intervention may be necessary for large and/or symptomatic lesions. Of note, the likelihood of their spontaneous regression is uncommon. We report 2 interesting cases of such a phenomenon for these lesions and discuss our findings in corroboration with current literature.

METHODS AND RESULTS

Two cases of spontaneous regression of pituitary lesions observed on serial neuroimaging are described. Based on their clinical history and radiological characteristics, the working diagnoses were that of a non-functioning PA and RCC, respectively. A systematic search of relevant publications in the English language is performed in PubMed and Google Scholar. Our findings show that there are 14 reported cases (including 1 of our patients) of spontaneous regression of non-functioning PA with good outcomes. Pertaining to RCCs, the limited evidence suggests that the incidence of their spontaneous regression is approximately 30%, similar to what is reported in the adult population. A separate discussion on the possible differential diagnosis of lymphocytic hypophysitis is also highlighted.

CONCLUSION

Pediatric pituitary lesions may present with unpredictable natural histories, as highlighted in our case examples. We advocate an extended period of follow-up by a cohesive multidisciplinary team. In meantime, collaborative efforts should focus on the establishing clinical practice guidelines to optimize the management of pituitary lesions in children.

Clinical features of pituitary carcinoma: analysis based on a case report and literature review

Introduction

Pituitary carcinoma (PC) is an extremely rare tumor of the adenohypophysis, which manifests as craniospinal dissemination and/or systemic metastasis. The diagnosis of PC is particularly difficult, as the clinical diagnosis only can be made after the metastasis is found. Owing to the complex diagnostic process and less effective treatments, the clinical prognosis of PC is usually very poor. Hence, it is of great significance to illustrate the diagnosis and treatment course of PC.

Methods

In this case report, we described a 48-year-old male patient who was diagnosed with pituitary adenoma (PA) initially and then was diagnosed with PC eventually after spinal cord metastasis was found, and we illustrated the treatment course as well. Furthermore, we summarized all the published case reports until now and provided a comprehensive review of the diagnosis, treatment, prediction, and clinical outcome of PC.

Results and Conclusions

We found that most PC patients had adrenocorticotropic hormone/prolactin (ACTH/PRL)-secreting tumors, Ki-67 ≥ 10%, and P53 positivity, which may have the potential to predict the transformation from PA to PC; surgery excision combined with temozolomide (TMZ) and radiotherapy is helpful to prolong the survival of PC patients.

From Nelson's Syndrome to Corticotroph Tumor Progression Speed: An Update

Since the first description of Nelson syndrome 60 years ago, the way to consider corticotroph pituitary neuroendocrine tumors (PitNETs) after bilateral adrenalectomy has evolved. Today, it is globally acknowledged that only a subset of corticotroph PitNETs is aggressive.After adrenalectomy, corticotroph tumor progression (CTP) occurs in about 30 to 40% of patients during a median follow-up of 10 years. When CTP occurs, various CTP speeds (CTPS) can be observed. Using simple metrics in patients with CTP, CTPS was reported to vary from a few millimeters to up to 40 mm per year. Rapid CTPS/ Nelson's syndrome was associated with more severe Cushing's disease, higher adrenocorticotropic hormone (ACTH) in the year following adrenalectomy, and higher Ki67 on pituitary pathology. Complications such as apoplexy, cavernous syndrome, and visual defects were associated with higher CTPS. During follow-up, early morning ACTH, absolute variations properly reflected CTPS. Finally, CTPS was not higher after than before adrenalectomy, suggesting that cortisol deprivation after adrenalectomy does not impact CTPS in a majority of patients.Taken together, rapid CTPS/ Nelson's syndrome probably reflects the intrinsic aggressiveness of some corticotroph PitNETs. The precise molecular mechanisms related to corticotroph PitNET aggressiveness remain to be deciphered. Regular MRIs combined with intermediate morning ACTH measurements probably provide a reliable way to detect early and manage fast-growing tumors and, therefore, limit the complications.

Adrenocorticotropic Hormone Producing Pituitary Carcinoma in the Falx Cerebri, Retroclival Region, Ethmoidal Cells, and Other Locations

Pituitary carcinoma is a condition defined by metastasis of a pituitary tumor to a distant location, and it is a very rare type of adenohypophyseal tumor. We present a case of a 29-year-old female who was followed up in our Endocrinology Department. Past medical history included the diagnosis of Cushing disease and transsphenoidal tumor resection at 12 years of age, followed by transcranial resection two years later because of persistently elevated adrenocorticotropic hormone (ACTH). Despite the surgical management, the patient persisted with increased ACTH and hypercortisolism, and, thus, bilateral adrenalectomy was performed a year later. Two years after the procedure, the patient presented with a newly diagnosed pituitary macroadenoma, and the diagnosis of Nelson syndrome was made. Linear accelerator radiotherapy was given, which reduced the size of the tumor. Later, several imaging studies showed multiple lesions on the falx cerebri, posterior clinoid process, retroclival region, cerebellopontine angle, pterygopalatine fossa, infratentorial region, and posterior ethmoidal cells. Biopsy and immunohistochemistry of the falx cerebri lesions described ACTH-producing pituitary adenocarcinoma. Treatment was given with intramuscular octreotide, dabrafenib, and trametinib. Despite persistently elevated ACTH levels, the patient has since remained clinically stable, without new development or worsening of symptoms. There are three unique aspects of our case. First, we reported an unusual presentation of this disease, since the patient in our case was a female with an early age of onset. Second, this is the first reported case demonstrating pituitary carcinoma in the falx cerebri. Third, the prognosis of pituitary carcinoma is usually very poor, and mortality is extremely high; however, the patient in our case has been followed up for seven years since the diagnosis of the metastatic lesions and has remained clinically stable.

Aggressive and Metastatic Pituitary Neuroendocrine Tumors: Therapeutic Management and Off-Label Drug Use

Pituitary neuroendocrine tumors (PitNETs) are the most common pituitary tumors and the second most common brain tumors. Although the vast majority (>90%) are benign, a small percentage (<2%) are aggressive. These aggressive PitNETs (AgPitNETs) are defined by the presence of radiological invasion, a high rate of cell proliferation, resistance to conventional treatments, and/or a high propensity for recurrence. Lastly, there are the rare pituitary carcinomas, also known as metastatic PitNETs (MetPitNETs), which account for only 0.2% of cases and are defined by the presence of craniospinal or distant metastases. At present, there are no definitive factors that allow us to predict with certainty the aggressive behavior of PitNETs, making the therapeutic management of AgPitNETs a real challenge. Surgery is considered the first-line treatment for AgPitNETs and MetPitNETs. Radiation therapy can be effective in controlling tumor growth and regulating hormone hypersecretion. Currently, there are no approved non-endocrine medical therapies for the management of AgPitNETs/MetPitNETs, mainly due to the lack of randomized controlled clinical trials. As a result, many of the medical therapies used are off-label drugs, and several are under investigation. Temozolomide (TMZ) is now recognized as the primary medical treatment following the failure of standard therapy (medical treatment, surgery, and radiotherapy) in AgPitNETs/MetPitNETs due to its ability to improve overall and progression-free survival rates in responding patients over 5 years. Other therapeutic options include pituitary-targeted therapies (dopamine agonists and somatostatin analogs), hormonal antisecretory drugs, non-hormonal targeted therapies, radionuclide treatments, and immunotherapy. However, the number of patients who have undergone these treatments is limited, and the results obtained to date have been inconsistent. As a result, it is imperative to expand the cohort of patients undergoing treatment to better determine the therapeutic efficacy and safety of these drugs for individuals with AgPitNETs/MetPitNETs.

Case report: Identification of potential prognosis-related LAG3 overexpression and DICER1 mutation in pituitary carcinoma: two cases

Metastatic PitNETs are a rare life-threatening condition with poor prognosis and documentation. Due to the scarce literature and lack of precise treatment, we hope to better characterise PitNET using the next-generation whole exon sequencing (WES) and RNA sequencing. This case study outlines a 54 years-old man and a 52 years-old woman who were both diagnosed with PitNET and analysis of peripheral blood and tumours were performed by WES and RNA sequencing. Analysis showed that DICER1 mutations in precancerous lesions and LAG3 overexpression were significant in aiding the prognosis and diagnosis of PitNETs. The first case with overexpressed LAG3 and DICER1 mutation died 26 months later, and the second case with LAG3 overexpression achieved partial remission. This study revealed that heightened expression of LAG3 offered promising targets for ICI and mutations in DICER1 could provide markers for effective diagnosis and prognosis.

Non-functioning pituitary carcinoma: Case report and literature review

INTRODUCTION AND IMPORTANCE

Non-functional pituitary carcinoma is a rare neuroendocrine tumor. It is characterized by the presence of cerebrospinal or distant metastasis of an adenohypophysis tumor without any hypersecretion. Only a few cases of non-functional pituitary carcinomas have been reported in the literature.

CASE PRESENTATION

In this paper, we report the case of a 48-year-old female patient who presented with spinal pain and a mass facing the second thoracic vertebrae. Spinal magnetic resonance imaging (MRI) revealed the presence of pituitary and bilateral adrenal incidentalomas. The patient was operated and the histopathological examination of the specimen revealed a non-functional pituitary carcinoma variety "Null Cell".

DISCUSSION AND CONCLUSION

There are no clinical, biological, or radiological characteristics that reliably differentiate between non-functional pituitary adenoma and non-functional pituitary carcinoma. Management remains a challenge for clinicians and neurosurgeons. A combination of surgery, chemotherapy, and radiotherapy seems necessary to achieve tumor control.

Recent Therapeutic Advances in Pituitary Carcinoma

Pituitary carcinoma (PC) is a rare, aggressive malignancy that comprises 0.1-0.2% of all pituitary tumors. PC is defined anatomically as a pituitary tumor that metastasizes outside the primary intrasellar location as noncontiguous lesions in the central nervous system or as metastases to other organs. Similar to pituitary adenoma, PC originates from various cell types of the pituitary gland and can be functioning or nonfunctioning, with the former constituting the majority of the cases. Compression of intricate skull-based structures, excessive hormonal secretion, impaired pituitary function from therapy, and systemic metastases lead to debilitating symptoms and a poor survival outcome in most cases. PC frequently recurs despite multimodality treatments, including surgical resection, radiotherapy, and biochemical and cytotoxic treatments. There is an unmet need to better understand the pathogenesis and molecular characterization of PC to improve therapeutic strategies. As our understanding of the role of signaling pathways in the tumorigenesis of and malignant transformation of PC evolves, efforts have focused on targeted therapy. In addition, recent advances in the use of immune checkpoint inhibitors to treat various solid cancers have led to an interest in exploring the role of immunotherapy for the treatment of aggressive refractory pituitary tumors. Here, we review our current understanding of the pathogenesis, molecular characterization, and treatment of PC. Particular attention is given to emerging treatment options, including targeted therapy, immunotherapy, and peptide receptor radionuclide therapy.

Natural history of pituitary carcinoma with metastasis to the cervical spine: illustrative case

BACKGROUND

Pituitary carcinoma is a rare tumor of the adenohypophysis with noncontiguous craniospinal dissemination and/or systemic metastases. Given the rarity of this malignancy, there is limited knowledge and consensus regarding its natural history, prognosis, and optimal treatment.

OBSERVATIONS

The authors present the case of a 46-year-old woman initially treated with invasive prolactin-secreting pituitary macroadenoma who developed metastatic disease of the cervical spine 6 years later. The patient presented with acutely worsening compressive cervical myelopathy and required posterior cervical decompression, tumor resection, and instrumented arthrodesis for posterolateral fusion.

LESSONS

This case underscores the importance of long-term monitoring of hormone levels and having a high clinical suspicion for metastatic disease to the spine in patients presenting with acute myelopathy or radiculopathy in the setting of previously treated invasive secreting pituitary adenoma.

The evolution in pituitary tumour classification: a clinical perspective

Objective

Pituitary tumours comprise a pathologically and clinically diverse group of neoplasms. Classification frameworks have changed dramatically in the past two decades, reflecting improving understanding of tumour biology. This narrative review examines the evolution of pituitary tumour classification, from a clinical perspective.

Results

In 2004, pituitary tumours were classified as 'typical' or 'atypical', based on the presence of markers of proliferation, Ki67, mitotic count and p53. In 2017, the new WHO marked a major paradigm shift, with a new focus on lineage-based classification, determined by transcription factor and hormonal immunohistochemistry. The terms 'typical' and 'atypical' were omitted, though the importance of proliferative markers Ki67 and mitotic count was acknowledged. The recent WHO 2022 classification incorporates further refinements, specifically recognising some less common types that may represent less well-differentiated tumours. Whilst 'high risk' tumour types have been identified, further work is still required to improve prognostication.

Conclusions

Recent WHO classifications have marked significant progress in the diagnostic evaluation of pituitary tumours, though shortcomings and challenges remain for both clinicians and pathologists in managing these tumours.

Clinical Biology of the Pituitary Adenoma

All endocrine glands are susceptible to neoplastic growth, yet the health consequences of these neoplasms differ between endocrine tissues. Pituitary neoplasms are highly prevalent and overwhelmingly benign, exhibiting a spectrum of diverse behaviors and impact on health. To understand the clinical biology of these common yet often innocuous neoplasms, we review pituitary physiology and adenoma epidemiology, pathophysiology, behavior, and clinical consequences. The anterior pituitary develops in response to a range of complex brain signals integrating with intrinsic ectodermal cell transcriptional events that together determine gland growth, cell type differentiation, and hormonal production, in turn maintaining optimal endocrine health. Pituitary adenomas occur in 10% of the population; however, the overwhelming majority remain harmless during life. Triggered by somatic or germline mutations, disease-causing adenomas manifest pathogenic mechanisms that disrupt intrapituitary signaling to promote benign cell proliferation associated with chromosomal instability. Cellular senescence acts as a mechanistic buffer protecting against malignant transformation, an extremely rare event. It is estimated that fewer than one-thousandth of all pituitary adenomas cause clinically significant disease. Adenomas variably and adversely affect morbidity and mortality depending on cell type, hormone secretory activity, and growth behavior. For most clinically apparent adenomas, multimodal therapy controlling hormone secretion and adenoma growth lead to improved quality of life and normalized mortality. The clinical biology of pituitary adenomas, and particularly their benign nature, stands in marked contrast to other tumors of the endocrine system, such as thyroid and neuroendocrine tumors.

Delayed Craniospinal Metastasis of Aggressive Nonfunctioning Pituitary Adenomas as Pituitary Carcinomas

Background Clinical behavior of pituitary neoplasms is peculiar and notoriously difficult to predict. While aggressive tumors are common, metastasis is very rare, can be highly delayed, and there are no histological or clinical features to meaningfully predict this happening. Endocrinologically silent tumors are particularly difficult, as there is less opportunity to detect early metastasis. Together, this amounts to a situation of uncertainty over the appropriate management of such tumors before and after metastasis.

Case Description The authors report two cases of nonfunctioning aggressive pituitary adenoma (APA) each requiring two transsphenoidal surgeries, a transcranial resection and radiotherapy. Both these tumors subsequently metastasized caudally along the neuraxis, years later, as a null cell carcinoma associated with a germline CHEK2 mutation and a silent Crooke's cell carcinoma. The former represents a novel oncogenetic association.

Conclusion Delayed drop dural metastasis of pituitary carcinoma is becoming increasingly recognized. Surgical resection of the distant disease to confirm the diagnosis and relieve the mass effect, followed by temozolomide chemotherapy, is the current treatment of choice. The need for both long-term follow-up in patients with APA, and a high degree of suspicion toward dural-based radiographic findings is emphasized.

Pituitary Carcinoma Diagnosis and Survival Improvement, with Affordable Care Act Correlation: A SEER Database Study

Introduction Pituitary carcinomas are challenging tumors to diagnose and treat due to their rarity and limited data surrounding their etiology. Traditionally, these patients have exhibited poor survival. Over the last several decades, our understanding of pituitary carcinomas has dramatically increased, and there have been recent initiatives to improve patient access to health care, including the Affordable Care Act (ACA). This study investigates whether there were any changes in incidence and treatment outcomes of pituitary carcinoma that correlated with these advances.

Methods A retrospective case review was conducted utilizing the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute. Those with primary site pituitary tumors with noncontiguous metastases were identified from 1975 to 2016. Demographic data, overall, and cause-specific outcomes were obtained. The data were analyzed using SPSS to generate 5-year Kaplan–Meier curves.

Results The incidence of pituitary carcinoma pre- and post-ACA was 0.31 and 2.14 diagnoses/year, respectively. This represents a significant increase (Chi-square, p < 0.00002). In addition, 1-, 2-, and 5-year overall survival of these patients was determined to be 88.2, 74.0, and 66.6% which was significantly improved compared with prior studies. Cause-specific survival of these patients follow similar trends exhibiting 94.1, 79.0, 71.1% after 1, 2, and 5 years, respectively.

Conclusion The survival for pituitary carcinoma has improved significantly which signals a change in how practitioners should counsel their patients. There is a significant surge in the number of cases in the post-ACA timeline, which suggests that improving patient access has played a part in wider recognition and treatment initiation for this disease.

The Genomic Landscape of Corticotroph Tumors: From Silent Adenomas to ACTH-Secreting Carcinomas

Corticotroph cells give rise to aggressive and rare pituitary neoplasms comprising ACTH-producing adenomas resulting in Cushing disease (CD), clinically silent ACTH adenomas (SCA), Crooke cell adenomas (CCA) and ACTH-producing carcinomas (CA). The molecular pathogenesis of these tumors is still poorly understood. To better understand the genomic landscape of all the lesions of the corticotroph lineage, we sequenced the whole exome of three SCA, one CCA, four ACTH-secreting PA causing CD, one corticotrophinoma occurring in a CD patient who developed Nelson syndrome after adrenalectomy and one patient with an ACTH-producing CA. The ACTH-producing CA was the lesion with the highest number of single nucleotide variants (SNV) in genes such as USP8, TP53, AURKA, EGFR, HSD3B1 and CDKN1A. The USP8 variant was found only in the ACTH-CA and in the corticotrophinoma occurring in a patient with Nelson syndrome. In CCA, SNV in TP53, EGFR, HSD3B1 and CDKN1A SNV were present. HSD3B1 and CDKN1A SNVs were present in all three SCA, whereas in two of these tumors SNV in TP53, AURKA and EGFR were found. None of the analyzed tumors showed SNV in USP48, BRAF, BRG1 or CABLES1. The amplification of 17q12 was found in all tumors, except for the ACTH-producing carcinoma. The four clinically functioning ACTH adenomas and the ACTH-CA shared the amplification of 10q11.22 and showed more copy-number variation (CNV) gains and single-nucleotide variations than the nonfunctioning tumors.

Prognostic Factors for Recurrence in Pituitary Adenomas: Recent Progress and Future Directions

Pituitary adenomas (PAs) are benign lesions; nonetheless, some PAs exhibit aggressive behaviors, which lead to recurrence. The impact of pituitary dysfunction, invasion-related risks, and other complications considerably affect the quality of life of patients with recurrent PAs. Reliable prognostic factors are needed for recurrent PAs but require confirmation. This review summarizes research progress on two aspects—namely, the clinical and biological factors (biomarkers) for recurrent PAs. Postoperative residue, age, immunohistological subtypes, invasion, tumor size, hormone levels, and postoperative radiotherapy can predict the risk of recurrence in patients with PAs. Additionally, biomarkers such as Ki-67, p53, cadherin, pituitary tumor transforming gene, matrix metalloproteinase-9, epidermal growth factor receptor, fascin actin-bundling protein 1, cyclooxygenase-2, and some miRNAs and lncRNAs may be utilized as valuable tools for predicting PA recurrence. As no single marker can independently predict PA recurrence, we introduce an array of comprehensive models and grading methods, including multiple prognostic factors, to predict the prognosis of PAs, which have shown good effectiveness and would be beneficial for predicting PA recurrence.

Cervical Lymph Node Metastases from Central Nervous System Tumors: A Systematic Review

Introduction

Lymph node metastasis (LNM) from primary tumors of the central nervous system (CNS) is an infrequent condition, and classically it was thought that CNS tumors could not spread via the lymphatic route. Recent discoveries about this route of dissemination make its knowledge necessary for surgeons and pathologists to avoid delays in diagnosis and unnecessary treatments. The aim of this paper is to review the literature and to discuss the relevant pathogenetic mechanism and the cytologic features along with recommendations for surgical treatment of these cervical LNM.

Materials and Methods

Using PRISMA guidelines, we conducted a systematic review of the literature published from 1944 to 2021, updating the comprehensive review published in 2010 by our group.

Results

Our review includes data of 143 articles obtaining 174 patients with LNM from a primary CNS tumor. The mean age of the patients was 31.9 years (range, 0.1–87) and there were 61 females (35.1%) and 103 males (59.2%), and in 10 cases (5.7%) the gender was not specified. The more frequent sites of distant metastasis were bones (23%), lungs (11.5%) and non-cervical lymph nodes (11%).

Conclusion

Cervical LNM from CNS tumors is infrequent. Pathologic diagnosis can be obtained by fine-needle aspiration cytology in most cases, giving surgeons the option to plan the appropriate surgical treatment. Given the poor prognosis of these cases, the most conservative possible cervical dissection is usually the treatment of choice.

Corticotroph pituitary carcinoma with skeletal metastases masquerading as ectopic ACTH syndrome: a long and winding road to diagnosis

Summary

Pituitary carcinoma is a rare type of malignancy and only accounts for 0.1-0.2% of all pituitary tumours. Most pituitary carcinomas are hormonally active and they are mostly represented by corticotroph and lactotroph carcinomas. Corticotroph carcinoma can present as symptomatic Cushing's disease or can evolve from silent corticotroph adenoma which is not associated with clinical or biochemical evidence of hypercortisolism. We hereby present a case of a bone-metastasized corticotroph pituitary carcinoma masquerading as an ectopic adrenocorticotropic hormone (ACTH) syndrome in a patient with a history of a non-functioning pituitary macro-adenoma. Our patient underwent two transsphenoidal resections of the primary pituitary tumour followed by external beam radiation therapy. Under hydrocortisone substitution therapy she developed ACTH-dependent hypercortisolism without arguments for recurrence on pituitary MRI and without central-to-peripheral ACTH-gradient on inferior petrosal sinus sampling, both suggesting ectopic production. Ultimately, she was diagnosed with an ACTH-secreting vertebral metastasis originating from the primary pituitary tumour. This case report demonstrates the complex pathophysiology of pituitary carcinoma and the long diagnostic work-up. Certain features in pituitary adenoma should raise the suspicion of malignancy.

Learning points

The diagnosis of pituitary carcinoma can only be made based on documented metastasis, therefore, due to the often long latency period between the detection of the primary tumour and the occurrence of metastasis, the diagnostic work-up most often spans over multiple years. Pituitary carcinoma including corticotroph carcinoma is very rare in contrast to pituitary adenoma and only accounts for 0.1-0.2% of all pituitary tumours. Histopathology in pituitary adenoma should certainly accomplish the following goals: accurate tumour subtyping and assessment of tumoural proliferative potential. Repeated recurrence of pituitary adenoma after surgical resection, a discrepancy between biochemical and radiological findings, resistance to medical and radiation therapy, and silent tumours becoming functional are all hallmarks of pituitary carcinoma. Silent corticotroph adenomas are non-functioning pituitary adenomas that arise from T-PIT lineage adenohypophyseal cells and that can express adrenocorticotropic hormone on immunohistochemistry, but are not associated with biochemical or clinical evidence of hypercortisolism. Silent corticotroph adenomas exhibit a more aggressive clinical behaviour than other non-functioning adenomas. Treatment options for corticotroph carcinoma include primary tumour resection, radiation therapy, medical therapy, and chemotherapy. Sometimes bilateral adrenalectomy is necessary to achieve sufficient control of the cortisol excess.

High-risk pituitary adenomas and strategies for predicting response to treatment

High-risk pituitary adenomas are aggressive. They show clinical and imaging features similar to those of carcinomas, including infiltration of the surrounding brain structures, but lack cerebrospinal or systemic metastases. In addition, they display distinct behavior, including tendency for fast growth and frequent recurrences, which are difficult to control. The term "high-risk" adenoma was first introduced in the 4th edition of the World Health Organization Classification of Endocrine Tumors in 2017. Five defined adenoma types belong to this category, including sparsely granulated somatotroph, lactotroph in men, Crooke cell, silent corticotroph, and plurihormonal PIT-1 positive adenomas. The morphological and immunohistochemical characteristics of high-risk adenomas are herein described in detail. In addition, the clinical features and the treatment options are presented. This review focuses on predictive markers assessed by immunohistochemistry, which help clinicians to design the appropriate treatment strategies for high-risk adenomas. Somatostatin receptor status predicts effectiveness of postsurgical treatment with somatostatin analogs, and MGMT expression predicts response to treatment with temozolomide. This comprehensive review presents the clinical and pathological features of high-risk pituitary adenomas, underlines the contribution of immunohistochemistry, and emphasizes the leading role of pathology in the design of optimal clinical management.

Demographic and socioeconomic disparities of pituitary adenomas and carcinomas in the United States

INTRODUCTION

Growth of some pituitary tumors is driven by hormones which vary in concentration along the lines of patient socioeconomic status. Thus, pituitary tumors may exhibit disparities in incidence upon stratification by socioeconomic variables. Exploring for these disparities could provide direction in tumor etiology elucidation and identification of healthcare inequalities.

METHODS

To investigate pituitary adenoma and carcinoma incidence (per 100,000) with respect to sex, age, income, residence, and race/ethnicity, we searched the largest American administrative dataset (1997-2016), the National (Nationwide) Inpatient Sample (NIS), which surveys 20% of United States (US) discharges.

RESULTS

Annual national incidence was 2.80 for adenomas and 0.046 for carcinomas. For adenomas, males had an incidence of 2.63, similar (p = 0.17) to females at 2.78; likewise, for carcinomas, males had a statistically equivalent (p = 0.24) incidence at 0.051 to females at 0.041. Amongst age groups, for adenomas incidence progressively rose, peaking 65-84 years old (6.12), before declining. For adenomas and carcinomas respectively, patients with low income had an incidence of 2.66 and 0.044, similar (p = 0.11; p = 0.72) to the 3.01 and 0.041 of middle/high income patients. Incidence was greatest for adenomas amongst urban centers (3.47), followed by rural (3.16) and suburban (3.01) communities. Examining race/ethnicity (p = 0.0000016), for adenomas, incidences amongst Blacks, Asian/Pacific Islanders, Hispanics, and Whites were as follows, respectively: 3.64, 2.57, 2.54, 2.44. Annually, incidence for adenomas was increasing (τ = 0.63, p = 0.00021), but decreasing (τ = -0.60, p = 0.00085) for carcinomas. Specifically, for carcinomas incidence was only decreasing for females and the middle/high income.

CONCLUSION

In the US, time-enduring healthcare disparities were identified for pituitary adenomas and carcinomas, against the background of sociodemographic strata. For carcinomas, annual incidence was declining only for middle/high income patients and females, which supporting prior investigations that low income patients and males are experiencing barriers to definitive treatment for pituitary adenomas. Incidence was also found to be greatest Blacks and urban residents.

Recurrent Macroprolactinoma with Malignant Conversion to Carcinoma with Spinal Metastasis

In contrast to pituitary adenomas, pituitary carcinomas represent a rare malignant neoplasm with a remarkable high mortality. Pituitary carcinomas can arise from any pituitary tumor cell line and are determined to be carcinomas when there is distant metastasis or central nervous system dissemination. In this case vignette, we describe a rare case of malignant prolactinoma with intraspinal metastasis, and we also provide a review of relevant literature and treatment.

What to Do with Incidentally Discovered Pituitary Abnormalities?

Pituitary incidentalomas are discovered in approximately 10% to 40% of brain images. A complete patient history, physical examination, and dedicated pituitary function testing are needed, and subsequent results should lead to appropriate patient management. However, most lesions are asymptomatic pituitary adenomas or Rathke cleft cysts with a benign course. Many lesions can be clinically significant, including prolactinomas or other pituitary adenomas that warrant specific pituitary disease treatment. In other cases, mass effect causing visual compromise or refractory headache indicates a need for surgery. Here, various facets of a complex evaluation and treatment algorithm for pituitary incidentalomas are reviewed.

Evolution of a refractory prolactin-secreting pituitary adenoma into a pituitary carcinoma: report of a challenging case and literature review

BACKGROUND

Pituitary carcinomas (PCs), defined as distant metastases of pituitary neoplasms, are very rare malignancies. Because the clinical presentation of PCs is variable, early diagnosis and management remain challenging. PCs are always refractory to comprehensive treatments, and patients with PCs have extremely poor prognoses.

CASE PRESENTATION

We describe one case of a prolactin-secreting pituitary adenoma (PA) refractory to conventional therapy that evolved into a PC with intraspinal metastasis. A 34-year-old female was diagnosed with an invasive prolactin-secreting PA in 2009 and was unresponsive to medical treatment with bromocriptine. The tumor was gross totally removed via transsphenoidal surgery (TSS). However, the patient experienced multiple tumor recurrences or regrowth despite comprehensive treatments, including medical therapy, two gamma knife radiosurgeries (GKSs), and four frontal craniotomies. In 2016, she was found to have an intradural extramedullary mass at the level of the fourth lumbar vertebra. The intraspinal lesion was completely resected and was confirmed as a metastatic PC based on histomorphology and immunohistochemical staining. The literature on the diagnosis, molecular pathogenesis, treatment, and prognosis of patients with prolactin-secreting PCs was reviewed.

CONCLUSION

PCs are very rare neoplasms with variable clinical features and poor prognosis. Most PCs usually arise from aggressive PAs refractory to conventional therapy. There is no reliable marker to identify aggressive PAs with a risk for progression to PCs; thus, it is difficult to diagnose these PCs early until the presence of metastatic lesions. It is still very challenging to manage patients with PCs due to a lack of standardized protocols for diagnosis and treatment. Establishing molecular biomarkers and the pathobiology of PCs could help in the early identification of aggressive PAs most likely to evolve into PCs.

Growth hormone secreting pituitary carcinomas: Case report and review of literature

OBJECTIVE

Pituitary carcinoma is a rare tumor, defined as a tumor of adenohypophyseal cells with systemic or craniospinal metastasis. We present a case of a growth hormone (GH)-secreting pituitary carcinoma with a review of literature to better characterize this disease.

DESIGN

Case report and literature review of 25 cases of GH-secreting pituitary carcinomas RESULTS: The age of diagnosis of GH-secreting carcinomas ranged 24-69 years old with a mean age of 44.4 with 52% of cases present in females. Mean latency period between diagnosis of acromegaly and transition to pituitary carcinoma was 11.4 years with mean survival being 3.4 years.

CONCLUSION

Growth hormone (GH)-secreting pituitary carcinomas are rare and hard to distinguish from aggressive pituitary adenomas. From review of literature, treatment options include debulking surgery, radiotherapy, or chemotherapy with dismal outcomes. There are no diagnostic markers or features which can predict metastatic progression of these tumors. Future studies with genomic landscapes and relevant tumor markers are needed to identify pituitary tumors most likely to metastasize.

Incidence, demographics, and survival of patients with primary pituitary tumors: a SEER database study in 2004-2016

Comprehensive investigations on the incidence and prognosis of pituitary tumors are still lacking. The present study aims to summarize the incidence, demographics, and survival outcome of pituitary adenoma on a population-based level. This study includes all pituitary adenomas reported in the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2016 in the United States. Extensive clinical and demographic characteristics were extracted and submitted to group comparisons. The standardized incidence rate was calculated and stratified by year at diagnosis, age/sex and age/treatment groups. The Kaplan–Meier analysis and multivariable regressions were performed to identify the factors associated with overall survival. A total of 47,180 pituitary tumors were identified, including 47,030 typical adenomas, 111 uncertain behavior pituitary adenomas, and 39 pituitary carcinomas. The overall standardized incidence rate was 4.8 cases per 100,000 person-years and the annual incidence rate continually trended upwards, with a peak seen in 2015. We noticed a bimodal age-related distribution in females and a unimodal distribution in males. In the multivariate regression analysis, the factors associated with prolonged survival included typical adenoma, younger age, and smaller tumor size. Whereas, black and male patients had worse overall survival. Our study provides a reliable estimate on the incidence of pituitary adenoma and confirms that the annual standardized incidence rate is increasing. Pituitary adenomas have a satisfactory long-term prognosis and age, tumor size, and tumor subtypes are related to overall survival. Though statistically significant, our inferential findings should be constrained within the limitations of SEER database.

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.

Research advances on the immune research and prospect of immunotherapy in pituitary adenomas

Background

Pituitary adenomas are one type of intracranial tumor, which can be divided into microadenoma (≤ 1 cm), macroadenoma (> 1 cm), and giant adenoma (≥ 4 cm) according to their diametral sizes. They are benign, typically slow-progressing, whereas the biological behavior of some of them is invasive, which presents a major clinical challenge. Treatment of some pituitary adenomas is still difficult due to drug resistance or multiple relapses, usually after surgery, medication, and radiation. At present, no clear prediction and treatment biomarkers have been found in pituitary adenomas and some of them do not cause clinical symptoms, so patients are often found to be ill through physical examination, and some are even found through autopsy. With the development of research on pituitary adenomas, the immune response has become a hot spot and may serve as a novel disease marker and therapeutic target.

The distribution and function of immune cells and their secreted molecules in pituitary adenomas are extremely complex. Researchers found that infiltration of immune cells may have a positive effect on the treatment and prognosis of pituitary adenomas. In this review, we summarized the advance of tumor immunity in pituitary adenomas, revealing the immunity molecules as potential biomarkers as well as therapeutic agents for pituitary adenomas.

Conclusion

The immune studies related to pituitary adenomas may help us find relevant immune markers. At the same time, the exploration of immunotherapy also provides new options for the treatment of pituitary adenomas.

Medical Therapy of Aggressive Pituitary Tumors

The rare aggressive pituitary adenoma presents a special challenge, due to the heterogenous presentation of the disease. The prognosis of aggressive pituitary adenomas has been improved due to recent studies demonstrating clinically-relevant efficacy of temozolomide, which is now considered first-line chemotherapy. However, there is limited data on second-line therapies in patients with treatment failure. This review presents a summary on the potential of medical therapies in aggressive pituitary tumors.

Pituitary Neoplasm Nomenclature Workshop: Does Adenoma Stand the Test of Time?

The WHO Classification of Endocrine Tumours designates pituitary neoplasms as adenomas. A proposed nomenclature change to pituitary neuroendocrine tumors (PitNETs) has been met with concern by some stakeholder groups. The Pituitary Society coordinated the Pituitary Neoplasm Nomenclature (PANOMEN) workshop to address the topic. Experts in pituitary developmental biology, pathology, neurosurgery, endocrinology, and oncology, including representatives nominated by the Endocrine Society, European Society of Endocrinology, European Neuroendocrine Association, Growth Hormone Research Society, and International Society of Pituitary Surgeons. Clinical epidemiology, disease phenotype, management, and prognosis of pituitary adenomas differ from that of most NETs. The vast majority of pituitary adenomas are benign and do not adversely impact life expectancy. A nomenclature change to PitNET does not address the main challenge of prognostic prediction, assigns an uncertain malignancy designation to benign pituitary adenomas, and may adversely affect patients. Due to pandemic restrictions, the workshop was conducted virtually, with audiovisual lectures and written précis on each topic provided to all participants. Feedback was collated and summarized by Content Chairs and discussed during a virtual writing meeting moderated by Session Chairs, which yielded an evidence-based draft document sent to all participants for review and approval. There is not yet a case for adopting the PitNET nomenclature. The PANOMEN Workshop recommends that the term adenoma be retained and that the topic be revisited as new evidence on pituitary neoplasm biology emerges.

A Silent Corticotroph Pituitary Carcinoma: Lessons From an Exceptional Case Report

Nowadays, neither imaging nor pathology evaluation can accurately predict the aggressiveness or treatment resistance of pituitary tumors at diagnosis. However, histological examination can provide useful information that might alert clinicians about the nature of pituitary tumors. Here, we describe our experience with a silent corticothoph tumor with unusual pathology, aggressive local invasion and metastatic dissemination during follow-up. We present a 61-year-old man with third cranial nerve palsy at presentation due to invasive pituitary tumor. Subtotal surgical approach was performed with a diagnosis of silent corticotroph tumor but with unusual histological features (nuclear atypia, frequent multinucleation and mitotic figures, and Ki-67 labeling index up to 70%). After a rapid regrowth, a second surgical intervention achieved successful debulking. Temozolomide treatment followed by stereotactic fractionated radiotherapy associated with temozolomide successfully managed the primary tumor. However, sacral metastasis showed up 6 months after radiotherapy treatment. Due to aggressive distant behavior, a carboplatine-etoposide scheme was decided but the patient died of urinary sepsis 31 months after the first symptoms. Our case report shows how the presentation of a pituitary tumor with aggressive features should raise a suspicion of malignancy and the need of follow up by multidisciplinary team with experience in its management. Metastases may occur even if the primary tumor is well controlled.

Aggressive Cushing's Disease: Molecular Pathology and Its Therapeutic Approach

Cushing's disease is a syndromic pathological condition caused by adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas (ACTHomas) mediated by hypercortisolemia. It may have a severe clinical course, including infection, psychiatric disorders, hypercoagulability, and metabolic abnormalities, despite the generally small, nonaggressive nature of the tumors. Up to 20% of ACTHomas show aggressive behavior, which is related to poor surgical outcomes, postsurgical recurrence, serious clinical course, and high mortality. Although several gene variants have been identified in both germline and somatic changes in Cushing's disease, the pathophysiology of aggressive ACTHomas is poorly understood. In this review, we focused on the aggressiveness of ACTHomas, its pathology, the current status of medical therapy, and future prospects. Crooke's cell adenoma (CCA), Nelson syndrome, and corticotroph pituitary carcinoma are representative refractory pituitary tumors that secrete superphysiological ACTH. Although clinically asymptomatic, silent corticotroph adenoma is an aggressive ACTH-producing pituitary adenoma. In this review, we summarize the current understanding of the pathophysiology of aggressive ACTHomas, including these tumors, from a molecular point of view based on genetic, pathological, and experimental evidence. The treatment of aggressive ACTHomas is clinically challenging and usually resistant to standard treatment, including surgery, radiotherapy, and established medical therapy (e.g., pasireotide and cabergoline). Temozolomide is the most prescribed pharmaceutical treatment for these tumors. Reports have shown that several treatments for patients with refractory ACTHomas include chemotherapy, such as cyclohexyl-chloroethyl-nitrosourea combined with 5-fluorouracil, or targeted therapies against several molecules including vascular endothelial growth factor receptor, cytotoxic T lymphocyte antigen 4, programmed cell death protein 1 (PD-1), and ligand for PD-1. Genetic and experimental evidence indicates that some possible therapeutic candidates are expected, such as epidermal growth factor receptor tyrosine kinase inhibitor, cyclin-dependent kinase inhibitor, and BRAF inhibitor. The development of novel treatment options for aggressive ACTHomas is an emerging task.

How to Classify and Define Pituitary Tumors: Recent Advances and Current Controversies

Pituitary tumors are very complex and heterogeneous and have a very wide range of proliferative and aggressive behaviors, and how to define and classify these tumors remains controversial. This review summarizes the epidemiology and progress in the classification and definition of pituitary tumors, as well as controversial issues. Based on the results of radiologic and autopsy studies, the prevalence of pituitary tumors has recently increased significantly. However, the majority of pituitary tumors are incidentally discovered and asymptomatic, and such tumors are called pituitary incidentalomas. Most of these incidentalomas do not induce symptoms, remain stable in size, and do not need treatment. The recent revised classification strategies mainly depend on immunohistochemistry (IHC) to detect pituitary hormones and pituitary transcription factors; therefore, the accuracy of diagnosing pituitary tumors has improved. Although new classification strategies and definitions for pituitary tumors have been presented, there are still some controversies. The term pituitary neuroendocrine tumor (PitNET) was proposed by the International Pituitary Pathology Club, and this terminology can encompass the unpredictable malignant behavior seen in the subset of aggressive pituitary adenomas (PAs). However, some endocrinologists who oppose this change in terminology have argued that the use of tumor in the terminology is misleading, as it gives PAs a harmful connotation when the majority are not aggressive. Such terminology may add new ambiguity to the origin of PAs and unnecessary anxiety and frustration for the majority of patients with benign PAs. The classification of aggressive PAs mainly relies on subjective judgment of clinical behavior and lacks objective biomarkers and unified diagnostic criteria. However, the term "refractory" could more accurately represent the characteristics of these tumors, including their clinical behaviors, radiological features, and pathologic characteristics. Moreover, the diagnostic criteria for refractory PAs are stricter, more objective, and more accurate than those for aggressive PAs. Early identification of patients with these tumors through recognition and increased awareness of the definition of refractory PAs will encourage the early use of aggressive therapeutic strategies.

Comprehensive analysis of the immunological landscape of pituitary adenomas: implications of immunotherapy for pituitary adenomas

PURPOSES

Immunotherapies for solid tumor are gaining traction in the clinic, however, the immunological landscape of pituitary adenomas (PAs) is not well defined. In the present study, we used the RNA-seq data of PAs to investigate the impact of immunological landscape on clinical features of pituitary adenomas and aim to evaluate the potential immunotherapy for PAs.

METHODS

We analyzed tumor-infiltrating immune cells in 115 PA samples using RNA-seq. Main immune cell types (B cells, CD8⁺ T cells, CD4⁺ T cells, macrophages and NK cells) were detected from the expression of genes. The association between immune cells abundance and immune checkpoint, as well as inflammatory factors were analyzed. 10 additional patients were enrolled for validation.

RESULTS

In RNA sequencing data, landscape of PAs were identified. Our computationally inferred immune infiltrates significantly associate with patient clinical features. Growth hormone-secreting adenomas (GHomas) were found with higher B cells and CD8⁺ T cells infiltration. Moreover, GHomas showed relative different genetic background, significant invasive behavior and independently correlated with reduced progress-free time. Tumor progression was related to increased expression of PD-1/PD-L1 and was associated with higher immune infiltration. Analysis of cancer-testis antigen expression and CD8⁺ T-cell abundance suggested CTAG2 and TSPYL6 were potential immunotherapeutic targets in GHomas and non-functioning adenomas, respectively.

CONCLUSIONS

Tumor-infiltrating immune cells confer important clinical and biological implications. Our results of immune-infiltrate levels in PAs may inform effective cancer vaccine and checkpoint blockade therapies and make it possible to take immunotherapy into invasive PAs.

Clinical features and their course of pituitary carcinoma with distant metastasis in a dog

An 11-year-old male toy poodle with neurological symptoms was diagnosed with a macroscopic pituitary tumor, which produced adrenocorticotropic hormone. Radiation therapy with a linear accelerator was performed for the pituitary tumor, and resulted in good local tumor control. However, serum endogenous adrenocorticotropic hormone concentrations were uncontrollable even after the tumor disappeared. Abdominal computed tomography revealed splenic masses, and splenectomy was performed. Histopathological examination of the surgical specimen showed tumor cells with eosinophilic and finely granular cytoplasm suggestive of endocrine origin. Since these cells were positive for adrenocorticotropic hormone, the case was diagnosed as a pituitary carcinoma with distant metastasis. Necropsy revealed multiple metastases to the abdominal organs. This is the first case report describing canine pituitary carcinoma with distant metastasis.

Cervical Nodal Metastatic Pituitary Carcinoma: A Case Report

Pituitary carcinomas are rare tumors with only 170 cases reported in the literature.¹ They form a very small proportion of pituitary tumors, which are commonly benign adenomas. Metastatic disease diagnosed by fine needle aspiration cytology is extremely rare and has only been reported in 6 patients,^2-5 3 of whom had cervical nodal metastases, with other sites of metastases being the liver and cervical vertebra. We report a case of cervical metastatic pituitary carcinoma diagnosed by core needle biopsy.

Malignancy course of pituitary adenoma in MEN1 syndrome: Clinical-Neuroradiological signs

Pituitary carcinomas (PCa) are extremely rare, indistinguishable from pituitary adenomas on histopathological grounds and have a poor prognosis. Most PCa start as PRL or ACTH secreting tumors in males, with relapsing invasive behaviour, refractoriness to medical and radiotherapy and increasing hormonal levels. The presence of distant metastases is still required for the diagnosis of PCa. The association with genetic endocrine diseases must be taken into account, since it adds further risk of evolution towards malignancy. Intradural spinal metastases have also been reported, so a complete craniospinal MR evaluation is recommended, when clinically indicated. We report a case of PCa, associated with MEN1 syndrome, with evidence of meningeal spread to the tentorium cerebelli, clival dura and spinal drop metastases mimicking spinal nerves schwannomas.

Targeted systemic and peptide radio-ligand therapy for aggressive pituitary tumors and carcinomas

Aggressive pituitary tumors comprise a rare but challenging subset of pituitary tumors. A major issue currently is the absence of a holistic definition that reliably identifies these tumors in a prospective manner. Although comprehensive evaluation of patient gender, age, local invasiveness, treatment responses, radiological and histopathological features may be informative to assess the potential for aggressiveness, a definitive diagnosis of this entity cannot be confidently made until disease progression is actually observed despite standard medical and surgical therapy. Failure to diagnose these aggressive pituitary tumors early may impede initiation of suitable intensive stepwise multimodal treatments, and lessen their ultimate therapeutic success. Even though current therapeutic options for aggressive pituitary tumors are suboptimal in many cases, large-scale randomized prospective clinic trials are impractical and will likely never be conducted due to the rarity of this disease entity. Therefore, the majority of novel therapies in this subset of tumors derive from case reports or small case series, which greatly reduces their validity to make strong recommendations. This chapter, as part of this series on aggressive pituitary tumors, focuses on the role of systemic targeted medical and peptide radio-receptor therapy in treatment of aggressive pituitary tumors and carcinomas, and discusses future directions in these fields.

Metastatic Pituitary Carcinoma Causing Cord Compression

A 39-year-old man with a history of recurrent pituitary tumor, Cushing disease, and Nelson syndrome presented with neck stiffness. He previously had bilateral adrenalectomy and hypophysectomy 27 years ago. He subsequently had repeat pituitary surgery, stereotactic radiosurgery, and chemotherapy for recurrent pituitary tumor. During follow-up, he was noted to have rising basal adrenocorticotrophin (ACTH) level. On examination, he was neurologically intact with no signs of myelopathy. Magnetic resonance imaging of the spine showed a large intradural extramedullary lesion causing cord compression at the C2-3 level. He underwent a cervical laminectomy and debulking of the lesion under continuous monitoring of motor-evoked and somatosensory-evoked potentials. He remained neurologically intact postoperatively. Histologic analysis revealed a tumor of pituitary origin with synaptophysin and ACTH expression. Pituitary drop metastasis is a rare entity and should raise a high index of suspicion given this clinical presentation. The radiologic appearance can mimic benign lesions such as meningioma or schwannoma.

Pituitary carcinoma: Two case reports and review of literature

BACKGROUND

Pituitary carcinoma is a rare type of malignancy that can be very difficult to diagnose and treat. Many cases were diagnosed at autopsy. Delays in diagnosis often adversely impact patients' outcomes. Even with prompt diagnosis, treatment decisions remain challenging in the absence of randomized controlled trials.

CASE SUMMARY

We report two cases of pituitary carcinoma in men with a history of pituitary adenoma. In the first case, a 55-year-old man was initially diagnosed with pituitary macroadenoma. He underwent subtotal debulking of the tumor followed by adjuvant radiotherapy. Subsequently, he developed relapsed disease and multifocal intracranial metastases and a diagnosis of pituitary carcinoma was rendered. He passed away despite several lines of systemic therapies including temozolomide, lomustine and bevacizumab. Another 52-year-old man was diagnosed with atypical pituitary adenoma with presentation of sudden onset of vision loss in the right eye. He had recurrent pituitary carcinoma with spinal metastases, treated with surgery, radiation and temozolomide.

CONCLUSION

Pituitary carcinoma is a rare neoplasm with poor prognosis that is difficult to diagnose and treat. The small number of cases restricts our ability to design randomized clinical trials. Management is largely driven by retrospective studies and case series. Establishing molecular biomarkers and comprehensive genomic profiling could help in decisions about diagnosis and management of pituitary carcinoma.

The Progress of Immunotherapy in Refractory Pituitary Adenomas and Pituitary Carcinomas

Most pituitary adenomas (PAs) are considered benign tumors, but approximately 0.2% can present metastasis and are classified as pituitary carcinomas (PCs). Refractory PAs lie between benign adenomas and true malignant PC and are defined as aggressive-invasive PAs characterized by a high Ki-67 index, rapid growth, frequent recurrence, and resistance to conventional treatments, including temozolomide. It is notoriously difficult to manage refractory PAs and PC because of the limited therapeutic options. As a promising therapeutic approach, cancer immunotherapy has been experimentally used for the treatment of many tumors, including pituitary tumors. The purpose of this review is to report the progress of immunotherapy in pituitary tumors, including refractory PAs and PCs. The tumor immune microenvironment has been recognized as a key contributor to tumorigenesis, progression, and prognosis. One study indicated that the number of CD68+ macrophages was positively correlated with tumor size and Knosp classification grade for tumor invasiveness. The infiltration of CD4+ and CD8+ T cells was relatively scant in these adenomas, but pituitary growth hormone (GH) adenomas exhibited significantly more CD4+ and CD8+ T cells than non-GH adenomas. These results suggest an association of CD68+ macrophage infiltration with an increase in pituitary tumor size and invasiveness. Another study suggested that a lower number of CD8+ lymphocytes is associated with cavernous sinus invasion and resistance to treatment with first-generation somatostatin analogs in acromegaly patients, highlighting a potential role of the tumor immune microenvironment in determining the prognosis of somatotroph pituitary tumors. Preclinical studies have indicated that widely varying degrees of programmed death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocytes (TILs) are found among different subtypes. Functional PAs and aggressive PAs express significantly higher levels of PD-L1 and TILs than other subtypes, indicating that PD-1 blockade might be a promising alternative therapy for patients with aggressive PAs. PD-L1 transcript and protein levels were found to be significantly increased in functioning (GH and prolactin-expressing) pituitary tumors compared to nonfunctioning (null cell and silent gonadotroph) adenomas. Moreover, primary pituitary tumors harbored higher levels of PD-L1 mRNA than recurrent tumors. These findings suggest the possibility of considering checkpoint blockade immunotherapy for functioning pituitary tumors refractory to conventional management. Animal models of Cushing's disease also demonstrated PD-L1 and TIL expression in cultured tumors and murine models, as well as the effectiveness of checkpoint blockade therapy in reducing the tumor mass, decreasing hormone secretion, and increasing the survival rate. Clinical studies show that immunotherapy may be an effective treatment in patients with pituitary tumors. One corticotroph carcinoma patient showed a significant reduction in hormone levels and shrinkage of the tumor size of primary and metastatic lesions immediately after investigational treatment with ipilimumab and nivolumab. However, another patient with corticotroph adenoma progressed rapidly after four cycles of anti-PD-1 (pembrolizumab) treatment. To date, there are two registered clinical trials of immunotherapy for pituitary tumors. One of them is the phase II clinical trial of nivolumab combined with ipilimumab for patients with aggressive pituitary tumors (NCT04042753). The other one is also a phase II clinical trial of the combination of nivolumab and ipilimumab for rare tumors, including pituitary tumors (NCT02834013). Both clinical trials are in the stage of recruiting patients and have not been completed. In summary, the results from preclinical research and clinical studies indicated that immunotherapy might be a promising alternative therapy for PCs and refractory PAs resistant to conventional treatments. The combination of immunotherapy and radiotherapy or temozolomide may have synergistic effects compared to a single treatment. More preclinical and clinical studies are needed to further indicate the exact efficacy of immunotherapy in pituitary tumors.

Spontaneous Pituitary Adenomas in Squirrel Monkeys (Saimiri sciureus)

On postmortem examination, 2 geriatric captive male squirrel monkeys (Saimiri sciureus) were found to have pituitary masses that were unassociated with previous experimental manipulation. Both animals were euthanized due to apparently unrelated clinical reasons. Histopathology and immunohistochemical staining classified these tumors as thyrotrophic and corticotrophic pituitary adenomas. These cases represent the first reports of this tumor type in squirrel monkeys.

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.

Nelson-Salassa Syndrome Progressing to Pituitary Carcinoma: A Case Report and Review of the Literature

Nelson-Salassa Syndrome (NSS) is a rare sequela of bilateral adrenalectomy as a treatment for persistent hypercortisolism in refractory Cushing disease (CD). Radiographic NSS has been observed in half of CD patients after adrenalectomy, yet often follows a mild course and rarely requires treatment. We present the case of a 44-year-old male with a history of CD who underwent primary treatments including transsphenoidal resection, radiotherapy, and bilateral adrenalectomy. He subsequently presented with acute vision loss and progressive somnolence. MRI revealed marked enlargement of an invasive sellar and suprasellar lesion exerting significant mass effect on the chiasm, and multiple new enhancing bony lesions. The patient was taken for emergent transsphenoidal resection and calvarial biopsy; visual function was restored postoperatively, and pathologic analysis confirmed pituitary carcinoma. While NSS typically follows an indolent course, pituitary carcinoma is a highly morbid metastatic disease, and has been theorized to occur at a higher frequency in the NSS population. We review all published cases of NSS to pituitary carcinoma progression, which further underscores the highly aggressive nature and considerable mortality of this patient cohort. Although mild, asymptomatic NSS is more commonly observed, symptomatic patients or those with rapid growth after adrenalectomy, should be targeted for routine close clinical follow-up and serial radiographic surveillance.

Virulence and antifungal susceptibility of microsatellite genotypes of Candida albicans from superficial and deep locations

A set of 185 strains of Candida albicans from patients with vulvovaginal candidiasis (VVC) and from non‐VVC clinical sources in southwest China was analysed. Strains were subjected to genotyping using CAI microsatellite typing and amplification of an intron‐containing region of the 25S rRNA gene. Microsatellite genotypes of strains from non‐VVC sources showed high polymorphism, whereas those of VVC were dominated by few, closely similar genotypes. However, among non‐VVC strains, two genotypes were particularly prevalent in patients with lung cancer. 25S rDNA genotype A was dominant in VVC sources (86.7%), whereas genotypes A, B, and C were rather evenly distributed among non‐VVC sources; known genotypes D and E were not found. In an experimental mouse model, isolates from lung cancer and AIDS patients proved to have higher virulence than VVC strains. Among 156 mice infected with C. albicans, 19 developed non‐invasive urothelial carcinoma. No correlation could be established between parameters of virulence, source of infection, and incidence of carcinoma. C. albicans strains from VVC were less susceptible to itraconazole than the strains from non‐VVC sources, whereas there was small difference in antifungal susceptibility between different 25S rDNA genotypes of C. albicans tested against amphotericin B, itraconazole, fluconazole, and flucytosine.

Lower all-cause mortality rates in patients harboring pituitary carcinoma following the introduction of temozolomide

OBJECTIVE

To evaluate the impact of temozolomide (TMZ) introduction on the survival of patients with pituitary carcinoma (PC) compared to aggressive pituitary adenoma (APA).

METHODS

Retrospective analysis of the Surveillance Epidemiology and End-Results database (SEER), including patients diagnosed with PC or APA between 1973 and 2015. Age-adjusted Kaplan-Meier analyses were performed, comparing all-cause mortality (ACM) rates before the year 2006, the time of TMZ introduction ("period 1"), and afterwards ("period 2"), in patients harboring PC and APA.

RESULTS

Among 107 patients, 18 (16.8%) harbored PC. The prevalence of PC and APA was comparable between genders, ethnicities and age strata. Patients harboring any pituitary tumor (PC or APA) had comparable risk for ACM and disease-specific mortality between the two time periods. However, among patients harboring PC, the risk for ACM was significantly lower in period 2 vs. period 1 (p = 0.021), becoming comparable to the risk of ACM in patients diagnosed with APA (p = 0.48).

CONCLUSIONS

In this large cancer-database-based analysis we observed improved overall survival in patients harboring PC in the years following the introduction of TMZ.

Unusual Course of an Aggressive Pituitary Prolactinoma: Case Report and Review of the Literature

Pituitary carcinomas are rare tumors with heterogeneous behaviors. Their carcinogenesis is still unknown. Consequently, treatment is multimodal and not standardized. Dopamine (DA) agonists are used as first-line treatments, while radiotherapy and surgery may be used for local control of invasive tumors. We describe the case of a 35-year-old male who presented with an invasive prolactinoma, managed initially with a transsphenoidal resection, postsurgical radiotherapy and DA agonists. The patient posteriorly presented a sole metastatic lesion to the lumbar spine that was later managed with local radiotherapy. Due to pituitary recurrence of the lesion, multiple surgical resections were needed until further treatment was declined. The clinical course in this patient was unusual. He lived for 13 years after initial diagnosis, with a very invasive tumor without systemic chemotherapy. Radiotherapy is used in pituitary tumors in which surgery fails; we hypothesize that it contributed to the malignant transformation and the late resistance to DA agonists in our patient. Several biomarkers in tumoral tissue have been evaluated regarding their association with malignancy and aggressive behaviors, although more studies are still needed. Therapeutic strategies are limited, without evidence on the impact on overall survival and prognosis. Risk factors associated with early malignancy in pituitary prolactinomas include recurrent behavior, increase in prolactin levels with a stable sellar mass, and secondary development of DA agonist resistance. However, there are still no conclusive answers as to whether physicians should rigorously follow up these patients or provide direct therapy with aggressive approaches.