Protocol for the examination of specimens from patients with pheochromocytomas and extra-adrenal paragangliomas

von Hippel-Lindau disease-related neoplasia with an emphasis on renal manifestations

von Hippel-Lindau (VHL) disease is characterized by biallelic inactivation of the VHL gene leading to abnormal or absent VHL protein function, and constitutive activation of hypoxia-inducible factors (HIF) that leads to pro-tumorigenic signaling. Individuals with VHL disease develop numerous cysts and tumors involving multiple organs including the kidneys, central nervous system, endolymphatic sac, lungs, pancreatobiliary system, adrenal glands, epididymis, and/or broad ligament. On histologic examination, these lesions show morphologic overlap as they are frequently characterized by cells with clear cytoplasm and prominent vascularity. In addition to distinguishing non-renal tumors from metastatic clear cell renal cell carcinoma, understanding site-specific histopathologic and immunophenotypic features of these tumors has several applications. This includes distinguishing VHL-related tumors from those that arise sporadically and lack VHL gene alterations, guiding further genetic workup, and helping distinguish between different genetic predisposition syndromes. In this context, immunohistochemical studies for markers such as paired box 8 (PAX-8), carbonic anhydrase 9 (CA9), and glucose transporter 1 (GLUT-1) have an important role in routine clinical practice and represent cost-effective diagnostic tools. The recent development of targeted therapeutics directed against HIF-mediated signaling represents a significant milestone in the management of VHL disease and highlights the importance of accurately diagnosing and characterizing the wide spectrum of VHL disease-associated lesions.

The Driver Role of Pathologists in Endocrine Oncology: What Clinicians Seek in Pathology Reports

Endocrine neoplasia represents an increasingly broad spectrum of disorders. Endocrine neoplasms range from incidental findings to potentially lethal malignancies. In this paper, we cover the impact of pathology in the interpretation of the clinic-pathological, genetic, and radiographic features underpinning these neoplasms. We highlight the critical role of multidisciplinary interactions in structuring a rational diagnostic and efficient therapeutic plan and emphasize the role of histopathological input in decision-making. In this context, standardized pathology reporting and second opinion endocrine pathology review represent relevant tools to improve the overall diagnostic workup of patients affected by endocrine tumors in every specific scenario. In fact, although a relevant proportion of cases may be correctly identified based on clinical presentation and biochemical/imaging investigations, a subset of cases presents with atypical findings that may lead to an inappropriate diagnosis and treatment plan based on a wrong pathological diagnosis if all pieces of the puzzle are not correctly considered. Pathologists have a responsibility to actively guide clinicians before and during surgical procedures to prevent unnecessary interventions. In all areas of endocrine pathology, pathologists must understand the complexity of tissue preservation and assay sensitivities and specificities to ensure the optimal quality and interpretation of diagnostic material. Finally, pathologists are central actors in tumor tissue biobanking, which is an expanding field in oncology that should be promoted while adhering to strict ethical and methodological standards.

Advances in Adrenal and Extra-adrenal Paraganglioma: Practical Synopsis for Pathologists

Adrenal paraganglioma (or "pheochromocytoma") and extra-adrenal paraganglioma, collectively abbreviated PPGL, are rare but spectacular nonepithelial neuroendocrine neoplasms. These are the most inheritable neoplasia of all, with a metastatic potential in a varying degree. As of such, these lesions demand careful histologic, immunohistochemical, and genetic characterization to provide the clinical team with a detailed report taking into account the anticipated prognosis and risk of syndromic/inherited disease. While no histologic algorithm, immunohistochemical biomarker, or molecular aberration single-handedly can identify potentially lethal cases upfront, the combined analysis of various risk parameters may stratify PPGL patients more stringently than previously. Moreover, the novel 2022 WHO Classification of Endocrine and Neuroendocrine Tumors also brings some new concepts into play, not least the reclassification of special neuroendocrine neoplasms (cauda equina neuroendocrine tumor and composite gangliocytoma/neuroma-neuroendocrine tumor) previously thought to belong to the spectrum of PPGL. This review focuses on updated key diagnostic and prognostic concepts that will aid when facing this rather enigmatic tumor entity in clinical practice.

Overview of the 2022 WHO Classification of Paragangliomas and Pheochromocytomas

This review summarizes the classification of tumors of the adrenal medulla and extra-adrenal paraganglia as outlined in the 5th series of the WHO Classification of Endocrine and Neuroendocrine Tumors. The non-epithelial neuroendocrine neoplasms (NENs) known as paragangliomas produce predominantly catecholamines and secrete them into the bloodstream like hormones, and they represent a group of NENs that have exceptionally high genetic predisposition. This classification discusses the embryologic derivation of the cells that give rise to these lesions and the historical evolution of the terminology used to classify their tumors; paragangliomas can be sympathetic or parasympathetic and the term pheochromocytoma is used specifically for intra-adrenal paragangliomas that represent the classical sympathetic form. In addition to the general neuroendocrine cell biomarkers INSM1, synaptophysin, and chromogranins, these tumors are typically negative for keratins and instead have highly specific biomarkers, including the GATA3 transcription factor and enzymes involved in catecholamine biosynthesis: tyrosine hydroxylase that converts L-tyrosine to L-DOPA as the rate-limiting step in catecholamine biosynthesis, dopamine beta-hydroxylase that is present in cells expressing norepinephrine, and phenylethanolamine N-methyltransferase, which converts norepinephrine to epinephrine and therefore can be used to distinguish tumors that make epinephrine. In addition to these important tools that can be used to confirm the diagnosis of a paraganglioma, new tools are recommended to determine genetic predisposition syndromes; in addition to the identification of precursor lesions, molecular immunohistochemistry can serve to identify associations with SDHx, VHL, FH, MAX, and MEN1 mutations, as well as pseudohypoxia-related pathogenesis. Paragangliomas have a well-formed network of sustentacular cells that express SOX10 and S100, but this is not a distinctive feature, as other epithelial NENs also have sustentacular cells. Indeed, it is the presence of such cells and the association with ganglion cells that led to a misinterpretation of several unusual lesions as paragangliomas; in the 2022 WHO classification, the tumor formerly known as cauda equina paraganglioma is now classified as cauda equina neuroendocrine tumor and the lesion known as gangliocytic paraganglioma has been renamed composite gangliocytoma/neuroma and neuroendocrine tumor (CoGNET). Since the 4th edition of the WHO, paragangliomas have no longer been classified as benign and malignant, as any lesion can have metastatic potential and there are no clear-cut features that can predict metastatic behavior. Moreover, some tumors are lethal without metastatic spread, by nature of local invasion involving critical structures. Nevertheless, there are features that can be used to identify more aggressive lesions; the WHO does not endorse the various scoring systems that are reviewed but also does not discourage their use. The identification of metastases is also complex, particularly in patients with germline predisposition syndromes, since multiple lesions may represent multifocal primary tumors rather than metastatic spread; the identification of paragangliomas in unusual locations such as lung or liver is not diagnostic of metastasis, since these may be primary sites. The value of sustentacular cells and Ki67 labeling as prognostic features is also discussed in this new classification. A staging system for pheochromocytoma and extra-adrenal sympathetic PGLs, introduced in the 8th Edition AJCC Cancer Staging Manual, is now included. This paper also provides a summary of the criteria for the diagnosis of a composite paragangliomas and summarizes the classification of neuroblastic tumors. This review adopts a practical question-answer framework to provide members of the multidisciplinary endocrine oncology team with a most up-to-date approach to tumors of the adrenal medulla and extra-adrenal paraganglia.

Significance of Alpha-inhibin Expression in Pheochromocytomas and Paragangliomas

Alpha-inhibin expression has been reported in pheochromocytomas and paragangliomas (PPGLs). We analyzed alpha-inhibin immunohistochemistry in 77 PPGLs (37 pheochromocytomas [PCCs] and 40 paragangliomas) and correlated the results with catecholamine profile, tumor size, Ki-67 labeling index, succinate dehydrogenase B subunit and carbonic anhydrase IX (CAIX) staining, and genetic pathogenesis. PPGLs were classified as pseudohypoxic cluster 1 disease with documented VHL mutation or SDHx mutation or biochemical phenotype, whereas NF1-driven and RET-driven PPGLs and those with a mature secretory (adrenergic or mixed adrenergic and noradrenergic) phenotype were classified as cluster 2 disease. The Cancer Genome Atlas data on INHA expression in PPGLs was examined. Alpha-inhibin was positive in 43 PPGLs (56%). Ki-67 labeling indices were 8.07% and 4.43% in inhibin-positive and inhibin-negative PPGLs, respectively (P<0.05). Alpha-inhibin expression did not correlate with tumor size. Alpha-inhibin was expressed in 92% of SDHx-related and 86% of VHL-related PPGLs. CAIX membranous staining was found in 8 of 51 (16%) tumors, including 1 SDHx-related PCC and all 5 VHL-related PCCs. NF1-driven and RET-driven PPGLs were negative for alpha-inhibin and CAIX. Alpha-inhibin was expressed in 77% of PPGLs with a pseudohypoxia signature, and 20% of PPGLs without a pseudohypoxia signature (P<0.05). PPGLs with a mature secretory phenotype were negative for CAIX. The Cancer Genome Atlas data confirmed higher expression of INHA in cluster 1 than in cluster 2 PPGLs. This study identifies alpha-inhibin as a highly sensitive (90.3%) marker for SDHx/VHL-driven pseudohypoxic PPGLs. Although CAIX has low sensitivity, it is the most specific biomarker of VHL-related pathogenesis. While alpha-inhibin cannot replace succinate dehydrogenase B subunit immunohistochemistry for detection of SDHx-related disease, it adds value in prediction of cluster 1 disease. Importantly, these data emphasize that alpha-inhibin is not a specific marker of adrenal cortical differentiation, as it is also expressed in PCCs.

A patient with paraganglioma undergoing laparoscopic resection: A case report

Paraganglioma is a very rare extraadrenal nonepithelial tumor. The number of cases of laparoscopic surgery in Paraganglioma is small and controversial. This study encountered a case of successful transperitoneal laparoscopic surgery for a 56-mm paraganglioma in a 53-year-old female. Moreover, previous reports on laparoscopic surgery for paraganglioma are reviewed.

Recurrence of a neuroendocrine tumor of adrenal origin: a case report with more than a decade follow-up

BACKGROUND

Neuroendocrine tumor (NET) with adrenocorticotropic hormone (ACTH) secretion are very rare. To our knowledge, no follow-up study is published for ACTH-secreting NET, regardless of the primary site, to show second occurrence of tumor after a long follow-up, following resection of primary tumor.

CASE PRESENTATION

Here, we describe a 49-year-old-man with cushingoid feature, drowsiness and quadriparesis came to emergency department at December 2005. Laboratory tests revealed hyperglycemia, metabolic alkalosis, severe hypokalemia, and chemical evidence of an ACTH-dependent hypercortisolism as morning serum cortisol of 57 μg /dL without suppression after 8 mg dexamethasone suppression test, serum ACTH level of 256 pg/mL, and urine free cortisol of > 1000 μg /24 h. Imaging showed only bilateral adrenal hyperplasia, without evidence of pituitary adenoma or ectopic ACTH producing tumors. Importantly, other diagnostic tests for differentiating Cushing disease (CD) from ectopic ACTH producing tumor, such as inferior petrosal sinus sampling (IPSS), corticotropin releasing hormone (CRH) stimulation test, octreotide scan or fluorodeoxyglucose (FDG)-positron emission tomography (PET) scan were not available in our country at that time. Therefore, bilateral adrenalectomy was performed that led to clinical and biochemical remission of hypercortisolism and decreased ACTH level to < 50 pg/mL, findings suggestive of a primary focus of NET in adrenal glands. After 11 years uncomplicated follow up, the ACTH level elevated up to 341 pg/mL and re-evaluation showed a 2 cm nodule in the middle lobe of the right lung. Surgical excision of the pulmonary nodule yielded a carcinoid tumor with positive immunostaining for ACTH; leading to decrease in serum ACTH level to 98 pg/mL. Subsequently after 7 months, serum ACHT levels rose again. More investigation showed multiple lung nodules with metastatic bone lesions accompanied by high serum chromogranin level (2062 ng/mL), and the patient managed as a metastatic NET, with bisphosphonate and somatostatin receptor analogues.

CONCLUSION

This case of surgically-treated NET showing a secondary focus of carcinoid tumor after one decade of disease-free follow-up emphasizes on the importance of long-term follow-up of ACTH-secreting adrenal NET.

Haemorrhagic retroperitoneal paraganglioma initially manifesting as acute abdomen: a rare case report and literature review

Background

Paragangliomas (PGLs) are extremely rare neuroendocrine tumours arising from extra-adrenal chromaffin cells. PGLs are clinically rare, difficult to diagnose and usually require surgical intervention. PGLs mostly present catecholamine-related symptoms. We report a case of Acute abdomen as the initial manifestation of haemorrhagic retroperitoneal PGL. There has been only one similar case reported in literature.

Case presentation

We present a unique case of a 52-year-old female with acute abdomen induced by haemorrhagic retroperitoneal PGL. The patient had a 5-h history of sudden onset of serve right lower quadrant abdominal pain radiating to the right flank and right lumbar region. Patient had classic symptoms of acute abdomen. Abdominal ultrasound revealed a large abdominal mass with a clear boundary. A Computed Tomography Angiography (CTA) of superior mesenteric artery was also performed to in the emergency department. The CTA demonstrated a large retroperitoneal mass measured 9.0 × 7.3 cm with higher density inside. A provisional diagnosis of retroperitoneal tumour with haemorrhage was made. The patient received intravenous fluids, broad-spectrum antibiotics and somatostatin. On the 3^rd day of admission, her abdominal pain was slightly relieved, but haemoglobin decreased from 10.9 to 9.4 g/dL in 12 h suggesting that there might be active bleeding in the abdominal cavity. Thus, we performed a midline laparotomy for the patient. Haemorrhage was successfully stopped during operation. The retroperitoneal tumour with haemorrhage was completely removed. The abdominal pain was significantly relieved after surgery. The patient initially presented with acute abdomen instead of catecholamine-related symptoms. The diagnosis of retroperitoneal PGL with haemorrhage was finally confirmed by postoperative pathological and immunohistochemical results. The postoperative course was uneventful. At the 1-year follow-up visit, no tumour recurrence was observed by Single Photon Emission Computed Tomography. A literature review was performed to further understand and analyse the aforementioned disease.

Conclusion

Acute abdomen as the initial manifestation of haemorrhagic retroperitoneal paraganglioma is extremely rare. Abdominal Computed Tomography is essential to locate the lesion and differentiate between other causes of acute abdomen. PGLs are hypervascular tumours. We should be aware that ruptured retroperitoneal PGL with massive bleeding could be life threatening and require emergency laparotomy.

Primary gallbladder paraganglioma: A case report and review of literature

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Incidental finding of primary gallbladder paraganglioma on routine laparoscopic cholecystectomy.

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Finding of gallbladder paraganglioma in setting of biliary colic.

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Rarity of gallbladder paraganglioma.

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Sufficient treatment of gallbladder paraganglioma with cholecystectomy.

Introduction

Paragangliomas are tumors arising from paraganglia of the autonomic nervous system. They are rare tumors and occurrence inside the gallbladder is exceptionally rare. Biliary paragangliomas are thought to be associated with the parasymphathetic fibers and are therefore non-functioning and benign. There are less than 10 cases reported in literature and majority are found incidentally upon cholecystectomy. There is no specific treatment for these tumors and resection is considered sufficient.

Case presentation

63 year old female presented with recurrent bliary colic exacerbated by fatty food. She underwent imaging work up that was consistent with biliary dyskinesia. She underwent uneventful elective laparoscopic cholecystectomy and was doing well post-operatively. Pathology report was significant for chronic cholecystitis, no calculi, and a small focus of paraganglioma.

Discussion

Little is known about primary gallbladder paragangliomas. Due to the non-functioning nature of these tumors there are felt to be benign. We know the paraganglia of the gallbladder consists of both parasymphathetic and sympathetic fibers. The sympathetic paragangliomas tend to act similar to pheochromocytomas and thus have malignant potential.

Conclusion

We presented a case in which a primary gallbladder paraganglioma was identified incidentally in a patient who presented with symptomatic biliary dyskinesia. Due to the rarity of primary gallbladder paraganglioma and limited reported cases, optimal follow up remains unknown.

A Case of Von Hippel-Lindau Disease with Bilateral Pheochromocytoma and Ectopic Hypersecretion of Intact Parathyroid Hormone in an Adolescent Girl

Von Hippel-Lindau disease is an autosomal dominant inherited syndrome predisposing to a variety of highly vascularised tumors in different organs. Although bilateral pheochromocytoma was reported in patients with von Hippel-Lindau disease, the coexistence of primary hyperparathyroidism is not a common condition. We report an observation of a primary hyperparathyroidism secondary to an ectopic secretion of intact parathyroid hormone in a 17-year-old girl with von Hippel-Lindau disease and bilateral pheochromocytoma. She presented with a newly diagnosed diabetes mellitus and a severe arterial hypertension. Blood tests disclosed hypercalcemia with increased intact PTH level. Cervical ultrasound and sestamibi scintigraphy were normal. Twenty-four-hour urinary normetanephrine level was highly elevated pointing to a catecholamine-secreting tumor. The abdominal computed tomography showed bilateral adrenal masses. MIBG scintigraphy exhibited a high accumulation of the tracer in both adrenal tumors. Genetic testing revealed a mutation of the VHL gene. The patient underwent a bilateral adrenalectomy. The postoperative outcome was marked by normalization of blood pressure, blood glucose, calcium, and PTH levels. In our case, the elevation of intact PTH and its spontaneous normalization after surgical treatment of pheochromocytomas confirms its ectopic secretion.

Data set for the reporting of pheochromocytoma and paraganglioma: explanations and recommendations of the guidelines from the International Collaboration on Cancer Reporting

BACKGROUND AND OBJECTIVES

The International Collaboration on Cancer Reporting (ICCR) is a not-for-profit to develop evidence-based, internationally agreed-upon standardized data sets for each anatomic site, to be used throughout the world. Providing global standardization of pathology tumor classification, staging, and other reporting elements will lead to improved patient management and enhanced epidemiological research.

METHODS

Pheochromocytoma and paraganglioma are uncommon and are frequently overlooked in registry data sets. Malignant criteria have previously been defined only when there was metastatic disease.

RESULTS

With recent recognition of a significant inheritance association and the development of risk stratification tools, this data set was created in order to obtain more meaningful outcomes and management data, using similar criteria across the global pathology community. Issues related to key core and non-core elements, especially clinical hormonal status, familial history, tumor focality, proliferative fraction, adverse or risk stratification features, and ancillary techniques, are discussed in the context of daily application to these types of specimens.

CONCLUSIONS

The ICCR data set, developed by an international panel of endocrine organ specialists, establishes a pathology-standardized reporting guide for pheochromocytoma and paraganglioma.

Endocrine Manifestations of Von Hippel-Landau Disease

Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder characterized by various endocrine, nonendocrine, benign, and malignant tumors in various organs. VHL tumor suppressor gene, located on short arm of chromosome 3 is responsible for this. Pheochromocytoma (PCC) is one of the important endocrine manifestations that needs to be ruled out in case of VHL suspicion. In this review, we summarize the endocrine manifestations of VHL disease and their management while giving case history of five such cases.

The Diagnosis and Clinical Significance of Paragangliomas in Unusual Locations

Paragangliomas are neuroendocrine neoplasms, derived from paraganglia of the sympathetic and parasympathetic nervous systems. They are most commonly identified in the head and neck, being most frequent in the carotid body, followed by jugulotympanic paraganglia, vagal nerve and ganglion nodosum, as well as laryngeal paraganglia. Abdominal sites include the well-known urinary bladder tumors that originate in the Organ of Zuckerkandl. However, other unusual sites of origin include peri-adrenal, para-aortic, inter-aortocaval, and paracaval retroperitoneal sites, as well as tumors in organs where they may not be expected in the differential diagnosis of neuroendocrine neoplasms, such as thyroid, parathyroid, pituitary, gut, pancreas, liver, mesentery, lung, heart and mediastinum. The distinction of these lesions from epithelial neuroendocrine neoplasms is critical for several reasons. Firstly, the determination of clinical and biochemical features is different from that used for epithelial neuroendocrine tumors. Secondly, the genetic implications are different, since paragangliomas/pheochromocytomas have the highest rate of germline susceptibility at almost 40%. Finally, the characterization of metastatic disease is unique in these highly syndromic lesions. In this review, we summarize updated concepts by outlining the spectrum of anatomic locations of paragangliomas, the importance of morphology in establishing the correct diagnosis, the clinical implications for management, and the impact of genetics on the distinction between multifocal primary tumors compared with malignant disease.

Immunohistochemical Biomarkers in Thyroid Pathology

The application of immunohistochemistry to the diagnosis of thyroid lesions has increased as new biomarkers have emerged. In this review, we discuss the biomarkers that are critical for accurate diagnosis, prognosis, and management. Immunohistochemical markers are used to confirm that an unusual tumor in the thyroid is indeed of thyroid origin, either of follicular epithelial or C-cell differentiation; the various mimics include nonthyroidal lesions such as parathyroid tumors, paragangliomas, thymic neoplasms, and metastatic malignancies. Tumors of thyroid follicular epithelial cells can be further subclassified using a number of immunohistochemical biomarkers that can distinguish follicular-derived from C-cell lesions and others that support malignancy in borderline cases. The use of mutation-specific antibodies can distinguish papillary carcinomas harboring a BRAF^V600E mutation from RAS-like neoplasms. Immunostains have been developed to further identify molecular alterations underlying tumor development, including some rearrangements. Altered expression of several biomarkers that are known to be epigenetically modified in thyroid cancer can be used to assist in predicting more aggressive behavior such as a propensity to develop locoregional lymphatic spread. Immunohistochemistry can assist in identifying lymphatic and vascular invasion. Biomarkers can be applied to determine dedifferentiation and to further classify poorly differentiated and anaplastic carcinomas. The rare tumors associated with genetic predisposition to endocrine neoplasia can also be identified using some immunohistochemical stains. The application of these ancillary tools allows more accurate diagnosis and better understanding of pathogenesis while improving prediction and prognosis for patients with thyroid neoplasms.

Challenging differential diagnosis of an extra-adrenal paraganglioma; the role of fine needle aspiration cytology

Paragangliomas are rare neoplasms that arise from neural crest cells of the autonomous system. Herein, we present a case of a 37-year-old patient with a history of retroperitoneal paraganglioma and tuberculous infection presenting with a paraganglioma of the neck that was initially misdiagnosed as metastatic tumor originating from the lungs. Cytological features from fine needle aspiration and immunocytochemistry pointed to the right diagnosis. However, distinguishing between primary and metastatic site of a paraganglioma can be very challenging due to the overlapping features of these entities. Furthermore, this case underlines the value of a detailed medical history in the era of modern diagnostic modalities. Diagn. Cytopathol. 2017;45:565-568. © 2017 Wiley Periodicals, Inc.

Frequency of Cushing's syndrome due to ACTH-secreting adrenal medullary lesions: a retrospective study over 10 years from a single center

Cushing's syndrome due to ectopic adrenocorticotropic hormone production from adrenal medullary lesions has occasionally been described. We retrospectively reviewed all 164 cases of Cushing's syndrome and 77 cases of pheochromocytomas during 10 years. Of all cases with Cushing's syndrome, only two cases (1.2 %) were due to ectopic adrenocorticotropic hormone production from adrenal medullary lesions (one case of pheochromocytoma and one case of adrenal medullary hyperplasia). Of all pheochromocytomas only the above-mentioned case (1.3 %) also gave rise to an ectopic adrenocorticotropic hormone syndrome. The clinical presentation of adrenocorticotropic hormone-secreting pheochromocytoma and adrenal medullary hyperplasia can be anything from mild to dramatic. These are rare conditions important to bear in mind in the workup of a patient with Cushing's syndrome or with pheochromocytoma. The identification of ectopic adrenocorticotropic hormone secretion from adrenal medullary lesions can be life-saving.

Current Diagnostic Status of Pheochromocytomaand Future Perspective: A Mini Review

Pheochromocytomas (PCCs) are rare neuroendocrine tumors. The current diagnostic tools are based on biochemistry and histopathology results, but heterogeneity of diagnostic markers, signs and symptoms of PCCs bring a lot of difficulties for these two current methods. Unfortunately, microscopic understanding of PCCs is not adequate for its confident prognosis and management. There are data linking specific genotypes of PCCs tumors to specific locations, typical biochemical phenotypes or future clinical behaviors. The detection of a germ-line mutation possibly can guide us to an early diagnosis, appropriate treatment, and regular surveillance with better prognosis for patients but also and their family members. Moreover, the latest discoveries in gene sequencing, circulating DNA (ctDNA) and circulating tumor cells (CTCs) will support the exact molecular pathogenesis of PCCs to provide an important basis for future PCCs managements.

Malignant pheochromocytoma secreting vasoactive intestinal peptide and response to sunitinib: a case report and literature review

OBJECTIVE

Malignant pheochromocytoma is rare and may be sporadic or have a genetic basis. Vasoactive intestinal peptide (VIP)-secreting pheochromocytoma has rarely been described in the literature, and treatment remains challenging in the absence of well-controlled randomized trials. The hypoxia-inducible factor-vascular endothelial growth factor axis has been implicated in pheochromocytoma when associated with germline Von-Hippel-Lindau (VHL) or succinate dehydrogenase (SDH) mutations, suggesting potential clinical activity of sunitinib in this setting.

METHODS

We present a case report of a patient with a VIP-secreting malignant pheochromocytoma manifested as severe watery diarrhea, with an exquisite clinical response to sunitinib. We review this rare clinical entity and the potential role of sunitinib in this context.

RESULTS

A 51-year-old male initially presented with a pheochromocytoma causing symptoms related to norepinephrine excess. He underwent adrenalectomy, which resulted in complete resolution of his symptoms. Three years later, he developed multifocal metastatic disease from his primary tumor, showing immunohistochemical evidence of VIP production accompanied by severe watery diarrhea and hypokalemia. The patient had a rapid, complete, and durable clinical response to sunitinib, but with only a minor radiological response and without significant toxicity. Genetic testing was negative for germline mutations in VHL, SDHB, SDHC, SDHD, transmembrane protein 127 (TMEM127) and for neurofibromatosis type 1 (NF-1).

CONCLUSION

To the best of our knowledge, this is the first report of a case of malignant VIP-producing pheochromocytoma that was responsive to sunitinib.

Urinary Bladder Paragangliomas: How Immunohistochemistry Can Assist to Identify Patients With SDHB Germline and Somatic Mutations

Urinary bladder paraganglioma (paraganglioma) is a rare tumor of chromaffin cells of the sympathetic system of the urinary bladder wall. We studied 14 cases of this entity and investigated the usefulness of SDHB protein staining by immunohistochemistry (IHC) as a diagnostic tool to identify patients with bladder paragangliomas that could be associated with SDHB gene mutations, as these patients have a more aggressive disease. Eleven tumors from these patients were stained by IHC. Six of 11 tumors were negative for SDHB staining by IHC with no cytoplasmic staining in tumor cells when compared with normal tissues. Five of these 6 negative cases were confirmed to be positive for germline SDHB mutations. One case showed negative staining and no germline SDHB mutation; however, further investigation of the tumor revealed a somatic SDHB gene deletion. The remaining 5 cases showed strong cytoplasmic staining, but they were negative for the presence of SDHB mutation. They were found to be either sporadic tumors or part of von Hippel-Lindau syndrome. Staining for SDHA was positive in all cases. Our study confirms that there is very good correlation between the presence of an SDHB mutation, whether germline or sporadic, and negative SDHB IHC staining in urinary bladder paragangliomas, and this is the first study to demonstrate that somatic mutations can be recognized by IHC staining.

Hyperplasia in glands with hormone excess

Five syndromes share predominantly hyperplastic glands with a primary excess of hormones: neonatal severe primary hyperparathyroidism, from homozygous mutated CASR, begins severely in utero; congenital non-autoimmune thyrotoxicosis, from mutated TSHR, varies from severe with fetal onset to mild with adult onset; familial male-limited precocious puberty, from mutated LHR, expresses testosterone oversecretion in young boys; hereditary ovarian hyperstimulation syndrome, from mutated FSHR, expresses symptomatic systemic vascular permeabilities during pregnancy; and familial hyperaldosteronism type IIIA, from mutated KCNJ5, presents in young children with hypertension and hypokalemia. The grouping of these five syndromes highlights predominant hyperplasia as a stable tissue endpoint and as their tissue stage for all of the hormone excess. Comparisons were made among this and two other groups of syndromes, forming a continuum of gland staging: predominant oversecretions express little or no hyperplasia; predominant hyperplasias express little or no neoplasia; and predominant neoplasias express nodules, adenomas, or cancers. Hyperplasias may progress (5 of 5) to neoplastic stages while predominant oversecretions rarely do (1 of 6; frequencies differ P<0.02). Hyperplasias do not show tumor multiplicity (0 of 5) unlike neoplasias that do (13 of 19; P<0.02). Hyperplasias express mutation of a plasma membrane-bound sensor (5 of 5), while neoplasias rarely do (3 of 14; P<0.002). In conclusion, the multiple distinguishing themes within the hyperplasias establish a robust pathophysiology. It has the shared and novel feature of mutant sensors in the plasma membrane, suggesting that these are major contributors to hyperplasia.

Thyroid Paraganglioma

Thyroid paragangliomas are rare tumors that arise from the inferior laryngeal paraganglia. Most patients are female and present with an asymptomatic thyroid nodule. Histologically, the tumor is composed of cells arranged in a well-defined nest (zellballen) pattern surrounded by a thin fibrovascular stroma. It is a diagnostic pitfall and is occasionally misdiagnosed as follicular neoplasm, medullary thyroid carcinoma, intrathyroid parathyroid proliferation, and especially secondary neuroendocrine tumors. Immunohistochemical stains (cytokeratin, parathyroid hormone, thyroid transcription factor 1, tyrosine hydroxylase, chromogranin A, synaptophysin, S100, calcitonin, carcinoembryonic antigen) are essential in establishing the diagnosis. Loss of succinate dehydrogenase complex, subunit B (SDHB), immunoexpression can be used to triage genetic testing because some mutations are associated with a higher risk for developing metastasis. Total thyroidectomy or lobectomy for solitary lesion is the preferred treatment. Elective lymph node dissection is usually not indicated. Postoperatively, patients should receive hormonal evaluation for functional disease and imaging for evaluation of multifocal or metastatic disease.

Pheochromocytomas and Paragangliomas: An Update on Recent Molecular Genetic Advances and Criteria for Malignancy

Pheochromocytomas are uncommon neuroendocrine tumors arising in the adrenal medulla, whereas paragangliomas arise from chromaffin cells in sympathetic and parasympathetic locations outside of the adrenal gland. Molecular genetic studies in the past few years have identified >10 genes involved in the pathogenesis of pheochromocytomas and paragangliomas, including RET oncogene, involved in the pathogenesis of multiple endocrine neoplasia (MEN) 2A and 2B, von Hippel-Lindau tumor-suppressor gene, neurofibromatosis type 1 gene, succinate dehydrogenase, THEM127, and several others. The presence of genetic alterations in some of these genes such as in MEN 2A and 2B can be used to diagnose these disorders clinically, and other mutations such as succinate dehydrogenase can be used in the pathologic prediction of benign and malignant pheochromocytomas and paragangliomas. Although it has been difficult to separate benign and malignant pheochromocytomas and paragangliomas, recent studies that may predict the behavior of these chromaffin-derived neoplasms have been reported. The Pheochromocytoma of the Adrenal Scale Score and the Grading system for Adrenal Pheochromocytoma and Paraganglioma scoring system are also discussed.

15 YEARS OF PARAGANGLIOMA: Pathology of pheochromocytoma and paraganglioma

Pathologists using their routine diagnostic tools can contribute both to the care of patients with pheochromocytoma/paraganglioma and to understanding the pathobiology of the tumors. They can document details of tissue organization and cytology that are accessible only by microscopy and can characterize admixtures of cell types that are morphologically distinct or show differential expression of immunohistochemical markers. Current roles and challenges for pathologists include differential diagnosis, identifying clues to the presence of hereditary disease, and effective communication of pathology information for clinical and research purposes. Future roles will increasingly involve risk stratification, identification of actionable targets for personalized therapies, and aiding the interpretation of molecular tests by helping characterize genetic variants of unknown significance. It remains to be determined to what extent the need for pathology input will be overshadowed by the availability of genetic testing and other molecular analyses at ever-decreasing cost, together with very effective clinical paradigms for risk stratification and patient care.

SDHB/SDHA immunohistochemistry in pheochromocytomas and paragangliomas: a multicenter interobserver variation analysis using virtual microscopy: a Multinational Study of the European Network for the Study of Adrenal Tumors (ENS@T)

Despite the established role of SDHB/SDHA immunohistochemistry as a valuable tool to identify patients at risk for familial succinate dehydrogenase-related pheochromocytoma/paraganglioma syndromes, the reproducibility of the assessment methods has not as yet been determined. The aim of this study was to investigate interobserver variability among seven expert endocrine pathologists using a web-based virtual microscopy approach in a large multicenter pheochromocytoma/paraganglioma cohort (n=351): (1) 73 SDH mutated, (2) 105 non-SDH mutated, (3) 128 samples without identified SDH-x mutations, and (4) 45 with incomplete SDH molecular genetic analysis. Substantial agreement among all the reviewers was observed either with a two-tiered classification (SDHB κ=0.7338; SDHA κ=0.6707) or a three-tiered classification approach (SDHB κ=0.6543; SDHA κ=0.7516). Consensus was achieved in 315 cases (89.74%) for SDHB immunohistochemistry and in 348 cases (99.15%) for SDHA immunohistochemistry. Among the concordant cases, 62 of 69 (~90%) SDHB-/C-/D-/AF2-mutated cases displayed SDHB immunonegativity and SDHA immunopositivity, 3 of 4 (75%) with SDHA mutations showed loss of SDHA/SDHB protein expression, whereas 98 of 105 (93%) non-SDH-x-mutated counterparts demonstrated retention of SDHA/SDHB protein expression. Two SDHD-mutated extra-adrenal paragangliomas were scored as SDHB immunopositive, whereas 9 of 128 (7%) tumors without identified SDH-x mutations, 6 of 37 (~16%) VHL-mutated, as well as 1 of 21 (~5%) NF1-mutated tumors were evaluated as SDHB immunonegative. Although 14 out of those 16 SDHB-immunonegative cases were nonmetastatic, an overall significant correlation between SDHB immunonegativity and malignancy was observed (P=0.00019). We conclude that SDHB/SDHA immunohistochemistry is a reliable tool to identify patients with SDH-x mutations with an additional value in the assessment of genetic variants of unknown significance. If SDH molecular genetic analysis fails to detect a mutation in SDHB-immunonegative tumor, SDHC promoter methylation and/or VHL/NF1 testing with the use of targeted next-generation sequencing is advisable.

Endocrine manifestations of von Hippel-Lindau disease

von Hippel-Lindau (VHL) disease is an autosomal dominant disorder caused by heterozygous mutations in the VHL tumor suppressor gene that is characterized by the occurrence of multiple endocrine and nonendocrine lesions. This review focuses on the endocrine manifestations of VHL disease. Pancreatic neuroendocrine proliferations (ductuloinsular complexes, islet dysplasia, endocrine microadenoma, and neuroendocrine tumors), pheochromocytomas, and extra-adrenal paragangliomas are important endocrine manifestations of VHL disease. They frequently display characteristic clinical, biochemical, and histopathologic features that, although not pathognomonic, can be helpful in suggesting VHL disease as the underlying etiology and distinguishing these tumors from sporadic cases. Recent improvements in treatment and outcomes of renal cell carcinomas have allowed pancreatic neuroendocrine tumors to emerge as a significant source of metastatic disease, making the accurate recognition and classification of these neoplasms by the pathologist of utmost importance to determine prognosis, treatment, and follow-up strategies for affected patients.

Penetrance and clinical features of pheochromocytoma in a six-generation family carrying a germline TMEM127 mutation

CONTEXT

The phenotype of familial pheochromocytoma (PHEO) associated with germline TMEM127 mutations (TMEM127-related PHEO) has not been clearly defined.

OBJECTIVE

This study aimed to investigate the penetrance, full phenotypic spectrum and effectiveness of clinical/genetic screening in TMEM127-related PHEO.

DESIGN, SETTING, AND PARTICIPANTS

Clinical and genetic screening, and genetic counseling were offered to 151 individuals from a six-generation family carrying a TMEM127 germline mutation in a referral center.

INTERVENTION AND MAIN OUTCOME MEASURES

TMEM127 genetic testing was offered to at-risk relatives and clinical surveillance for pheochromocytoma was performed in mutation-positive carriers.

RESULTS

Forty seven individuals carried the c.410-2A>C TMEM127 mutation. Clinical data were obtained from 34 TMEM127-mutation carriers followed up for 8.7 ± 8.1 years (range, 1-20 y). Pheochromocytoma was diagnosed in 11 carriers (32%) at a median age of 43 years. In nine patients, symptoms started at 29 years (range, 10-55 y) and two cases were asymptomatic. Tumors were multicentric in five (45%) and bilateral in five (45%) patients. Six patients (54%) had at least one adrenomedullary nodule less than 10 mm. No paragangliomas, distant metastases, or other manifestations were detected. Cumulative penetrance of pheochromocytoma was 0% at 0-20 years, 3% at 21-30 years, 15% at 31-40 years, 24% at 41-50 years, and 32% at 51-65 years. The youngest case was diagnosed at 22 years and the earliest symptoms were reported at age 10.

CONCLUSIONS

Tumor multicentricity, nodular adrenomedullary hyperplasia, and the occurrence of symptoms more than a decade earlier than the age at diagnosis are novel findings in TMEM127-related PHEO. The high penetrance of pheochromocytoma in this condition validates the benefits of genetic testing of at-risk relatives. We thus recommend that TMEM127 genetic testing should be offered to at-risk individuals at age 22 years and mutation carriers should undergo clinical surveillance annually.

A mimic of sarcomatoid adrenal cortical carcinoma: epithelioid angiosarcoma occurring in adrenal cortical adenoma

The adrenal gland is a site of various neoplasms; however, it is rarely involved by sarcomas. We present herein an unusual adrenal neoplasm consisting of epithelioid angiosarcoma and adrenal cortical adenoma. In this report, the authors highlight the diagnostic challenges associated with an epithelioid angiosarcoma occurring in an adrenal cortical neoplasm by providing a comprehensive discussion on the spectrum of vascular proliferations seen in the adrenal gland along with a roadmap for practicing pathologists. The presence of angiosarcoma within an adrenal cortical adenoma may represent a collision tumor; however, one can speculate that the rich vasculature of endocrine lesions can also create a favorable milieu for the occurrence of this phenomenon. While the latter needs to be further clarified, the presented case should be added to the unusual clinical presentations of vascular lesions of the adrenal gland mimicking a sarcomatoid adrenal cortical carcinoma.

Paragangliomas Arising in the Head and Neck: A Morphologic Review and Genetic Update

Seventy percent of parasympathetic paragangliomas arise in the head and neck and are nonsecretory. Awareness of the differential diagnosis based on location, overlapping morphology, and immunohistochemical profiles aids in the correct diagnosis, particularly on limited tissue samples. Moreover, 30% to 40% of head and neck paragangliomas are known to be associated with hereditary syndromes, with the succinate dehydrogenase enzyme family comprising the most frequent association. The pathologist's role is becoming increasing critical for facilitating optimal patient care beyond the initial tissue diagnosis of paraganglioma to include screening and documenting potential hereditary tumors requiring further patient counseling and testing.

Adrenal medullary hyperplasia is a precursor lesion for pheochromocytoma in MEN2 syndrome

Adrenal medullary hyperplasias (AMHs) are adrenal medullary proliferations with a size < 1 cm, while larger lesions are considered as pheochromocytoma (PCC). This arbitrary distinction has been proposed decades ago, although the biological relationship between AMH and PCC has never been investigated. Both lesions are frequently diagnosed in multiple endocrine neoplasia type 2 (MEN2) patients in whom they are considered as two unrelated clinical entities. In this study, we investigated the molecular relationship between AMH and PCC in MEN2 patients. Molecular aberrations of 19 AMHs and 13 PCCs from 18 MEN2 patients were determined by rearranged during transfection (RET) proto-oncogene mutation analysis and loss of heterozygosity (LOH) analysis for chromosomal regions 1p13, 1p36, 3p, and 3q, genomic areas covering commonly altered regions in RET-related PCC. Identical molecular aberrations were found in all AMHs and PCCs, at similar frequencies. LOH was seen for chromosomes 1p13 in 8 of 18 (44%), 1p36 in 9 of 15 (60%), 3p12-13 in 12 of 18 (67%), and 3q23-24 in 10 of 16 (63%) of AMHs, and for chromosome 1p13 in 13 of 13 (100%), 1p36 in 7 of 11 (64%), 3p12-13 in 4 of 11 (36%), and 3q23-24 in 11 of 12 (92%) of PCCs. Our results indicate that AMHs are not hyperplasias and, in clinical practice, should be regarded as PCCs, which has an impact on diagnosis and treatment of MEN2 patients. We therefore propose to replace the term AMH by micro-PCC to indicate adrenal medullary proliferations of less than 1 cm.

Neuroendocrine cancer. Closing the GAPP on predicting metastases

A promising grading system to predict metastasis in patients with phaeochromocytoma and paraganglioma assigns risk according to selected histological and other criteria. Such risk stratification might be useful for personalized management and screening programmes, as it could limit the costs of follow-up and reduce the risk of disseminated disease.

The adrenal medulla and extra-adrenal paraganglia: then and now

The past 25 years have witnessed revolutionary changes in the care of patients with pheochromocytomas and extra-adrenal paragangliomas. Germline mutations of at least 13 genes are now associated with tumor development, a greater degree of hereditary susceptibility than for any other human neoplasm. Somatic mutations, either of the same genes or of several additional ones with closely related functions, are also increasingly recognized. Clinicians are now aware of the genetic implications of a pheochromocytoma or paraganglioma. All patients are therefore offered genetic testing and receive lifelong surveillance. Almost all of the mutated genes have well-described correlations with clinical and biochemical phenotypes. Tumors arising in patients with mutations of the SDHB gene have at least a 30 % chance of metastasizing and typically produce norepinephrine and/or dopamine. Assay of plasma-free metanephrines serves as a highly sensitive and specific biochemical screen for the presence of catecholamine-producing tumors, and the dopamine metabolite methoxytyramine serves as a useful marker for detecting minimally functional tumors or their metastases. New functional imaging techniques provide highly sensitive tumor localization. In addition to differential diagnosis, pathologists play new roles in helping to identify hereditary disease and guiding the sequence of genetic testing.