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

Anaesthetic challenges in perioperative management of thoracic paraganglioma in an 8-year-old child

Pheochromocytomas (PCC) are catecholamine-secreting tumours that arise from chromaffin cells of the sympathoadrenal system. These rare catecholamine-secreting tumours arising from adrenal glands are termed as PCC and those from extra--adrenal sites are termed paraganglioma (PGL). Thoracic PGL is very rarely found. we report the anaesthetic challenges and management of an 8-year-old child with functional thoracic PGL and its successful outcome.

Seven Novel Genes Related to Cell Proliferation and Migration of VHL-Mutated Pheochromocytoma

Pheochromocytoma, as a neuroendocrine tumor with the highest genetic correlation in all types of tumors, has attracted extensive attention. Von Hipper Lindau (VHL) has the highest mutation frequency among the genes associated with pheochromocytoma. However, the effect of VHL on the proteome of pheochromocytoma remains to be explored. In this study, the VHL knockdown (VHL-KD) PC12 cell model was established by RNA interference (shRNA). We compared the proteomics of VHL-KD and VHL-WT PC12 cell lines. The results showed that the expression of 434 proteins (VHL shRNA/WT > 1.3) changed significantly in VHL-KD-PC12 cells. Among the 434 kinds of proteins, 83 were involved in cell proliferation, cell cycle and cell migration, and so on. More importantly, among these proteins, we found seven novel key genes, including Connective Tissue Growth Factor (CTGF), Syndecan Binding Protein (SDCBP), Cysteine Rich Protein 61 (CYR61/CCN1), Collagen Type III Alpha 1 Chain (COL3A1), Collagen Type I Alpha 1 Chain (COL1A1), Collagen Type V Alpha 2 Chain (COL5A2), and Serpin Family E Member 1 (SERPINE1), were overexpressed and simultaneously regulated cell proliferation and migration in VHL-KD PC12 cells. Furthermore, the abnormal accumulation of HIF2α caused by VHL-KD significantly increased the expression of these seven genes during hypoxia. Moreover, cell-counting, scratch, and transwell assays demonstrated that VHL-KD could promote cell proliferation and migration, and changed cell morphology. These findings indicated that inhibition of VHL expression could promote the development of pheochromocytoma by activating the expression of cell proliferation and migration associated genes.

Composite phaeochromocytoma with malignant peripheral nerve sheath tumour: A case report with summary of prior published cases

Composite phaeochromocytomas (CP) are extremely uncommon adrenal medullary tumours where phaeochromocytoma coexists with another adrenal medullary tumour also of neural crest origin. CP includes combination of phaeochromocytoma along with a component of neuroblastoma, ganglioneuroblastoma, ganglioneuroma, benign nerve sheath tumour or a malignant peripheral nerve sheath tumour (MPNST). Here we describe the morphological and immunohistochemical details of a case of CP with MPNST in a 30 years old lady, without history of neurofibromatosis. Only 6 cases of CP with MPNST have been reported so far. We have tabulated a summary of these prior published cases of phaeochromocytoma with MPNST. To our knowledge, this is the first literature review describing the clinico-pathological characteristics of these rare tumours.

Current trend in the diagnosis and management of malignant pheochromocytoma: Clinical and prognostic factors

Pheochromocytomas are tumors arising from the chromaffin cell of the adrenal gland and paragangliomas as tumors from extra-adrenal sympathetic chromaffin cells. The combined yearly incidence of pheochromocytoma and paraganglioma (PPGL) is approximately 0.8 per 100000 person/year. Malignant pheochro-mocytoma is defined only by the presence of metastasis, as there is no confirmatory histology or biomarkers. The most common metastatic sites of these chromaffin tumors are the lymph node, bone, lungs, and liver. This review focuses on relevant clinical and immunohistological factors that are predictive of malignant PPGL or metastasis and determinants of prognosis. Findings showed that the risk of malignant PPGL, along with disease survival, is closely associated with age, primary tumor size, gender, synchronous metastasis, and absence of surgical excision. Other essential biomarkers or immunohistology investigated were galectin-3, COX-2, nm-23, microRNA-210, ERBB-2 overexpression and succinate dehydrogenase subunit mutation, which were predictive of malignancy as well as disease prognosis. Curative resection is possible but most metastatic diseases are amenable to radiopharmaceuticals and chemotherapy due to late presentation. Other therapeutic options, like molecular-targeted therapy, are still undergoing clinical trials.

Genetic and epigenetic differences of benign and malignant pheochromocytomas and paragangliomas (PPGLs)

Pheochromocytomas and paragangliomas (PPGLs) are tumors arising from the adrenal medulla and sympathetic/parasympathetic paraganglia, respectively. According to Th e Cancer Genome Atlas (TCGA), approximately 40% of PPGLs are due to germ line mutations in one of 16 susceptibility genes, and a further 30% are due to somatic alterations in at least seven main genes (VHL, EPAS1, CSDE1, MAX, HRAS, NF1, RET, and possibly KIF1B). Th e diagnosis of malignant PPGL was straight forward in most cases as it was defined as presence of PPGL in non-chromaffin tissues. Accordingly, there is an extreme need for new diagnostic marker(s) to identify tumors with malignant prospective. Th e aim of this study was to review all suggested genetic and epigenetic alterations that are remarkably different between benign and malignant PPGLs. It seems that more than two genetic mutation clusters in PPGLs and other genetic and methylation biomarkers could be targeted for malignancy discrimination in different studies.

[Tumors of the adrenal glands : Update]

Nodular hyperplasias and adenomas are by far the most frequently resected tumors of the adrenal cortex followed by pheochromocytomas, which are either discovered incidentally or become conspicuous due to hormonal hypersecretions. Cortical nodes and adenomas are easy to diagnose using simple staining methods. Uncertain cortical carcinomas, pheochromocytomas and other tumors of the adrenal region require additional immunohistochemical staining methods. Determination of the dignity of tumors of the adrenal cortex necessitates at least the Weiss score (possibly in its modified form), for oncocytic tumors the Bisceglia score and for pediatric tumors the Wieneke score. The Ki-67 index must also be taken into consideration. For pheochromocytomas the PASS and the GAPP systeme are used.

Primary Renal Paragangliomas and Renal Neoplasia Associated with Pheochromocytoma/Paraganglioma: Analysis of von Hippel-Lindau (VHL), Succinate Dehydrogenase (SDHX) and Transmembrane Protein 127 (TMEM127)

Alterations of von Hippel-Lindau (VHL), succinate dehydrogenase (SDHX), and TMEM127 have been associated with the development of pheochromocytomas (PCs) and paragangliomas (PGLs) and are also associated with the development of renal neoplasms. This study involved 2 primary renal PGL and 12 cases of PC/PGL with associated renal neoplasia with a mean follow up of 74 months. Germline VHL and SDHX mutation status was obtained from the medical record. Immunohistochemistry for SDHB and mutation analysis for TMEM127 was performed, in addition to analysis of The Cancer Genome Atlas datasets for SDHX and TMEM127 mutated renal cell carcinomas (RCCs). The spectrum of renal neoplasia included clear cell and tubulocystic and papillary RCC, as well as a case of multiple papillary adenomas. Three patients had metastatic PC/PGL and three patients had VHL syndrome. Previously unreported TMEM127 alterations were identified in two patients, both without evidence of VHL syndrome or SDH-deficiency, and were classified as variants of uncertain significance. Primary renal PGL and neoplasia was associated with about 2% of 710 cases of PC/PGL. These were diagnosed concurrently or on average 27 months prior to the PC/PGL, and most were low-grade, low-stage clear cell RCCs. Up to half of patients with PC/PGL and renal neoplasia had VHL syndrome, SDH deficiency, or alterations in TMEM127. One (of three) case of metastatic PC/PGL had SDHB mutation and loss of SDHB by immunohistochemistry. The other two cases had retained SDHB expression.

Composite Pheochromocytoma/Paraganglioma-Ganglioneuroma: A Clinicopathologic Study of Eight Cases with Analysis of Succinate Dehydrogenase

Ganglioneuromas represent the most well-differentiated spectrum of neoplasia arising from the sympathetic nervous system, while neuroblastomas represent the most poorly differentiated counterpart, and ganglioneuroblastomas represent intermediate stages of differentiation. Small series of cases have documented the co-occurrence of ganglioneuroma with a pheochromocytoma (Pheo)/paraganglioma (PGL) component. We report the clinicopathologic features of eight such cases, diagnosed between 2003 and 2015 with a mean follow-up of 22 months (1-47), which were evaluated for syndrome associations, SDHB expression, and clinical outcome. Mutations of the succinate dehydrogenase (SDH) complex subunits (A, B, C, D, and SDHAF2) have been implicated in predicting metastatic behavior and in identifying possible paraganglioma syndromes. The proliferative index was calculated by manual quantification of Ki-67-positive cells at selected hot-spots using ImageJ (NIH). In our series, composite Pheo/PGL-ganglioneuromas predominantly involved the adrenal gland (Pheo 7, PGL 1). The cases had an equal gender distribution (males 4, females 4), with a mean age at diagnosis of 67 years (range 53 to 86 years), an average size of 5.2 cm (range 2 to 8.2 cm), an average weight of 49.3 g (7.8 to 144.7 g, n = 6), and the majority were functionally active (7 of 8, 88%). The mean Ki67 proliferation rate was 2% (range 0.3 to 3%), and all cases retained SDHB expression (8/8, 100%). No patient (0/8, 0%) developed metastatic disease on follow-up. One patient had a retroperitoneal composite PGL-ganglioneuroma in the setting of neurofibromatosis type 1. No recurrent disease or other associations were identified. In our study, composite Pheo/PGL-ganglioneuromas predominantly affected the adrenal gland in older patients, showed no loss of SDHB, and no disease recurrence was identified.

Biomarker, Molecular, and Technologic Advances in Urologic Pathology, Oncology, and Imaging

Urologic pathology is evolving rapidly. Emerging trends include the expanded diagnostic utility of biomarkers and molecular testing, as well as adapting to the plethora of technical advances occurring in genitourinary oncology, surgical practice, and imaging. We illustrate those trends by highlighting our approach to the diagnostic workup of a few selected disease entities that pathologists may encounter, including newly recognized subtypes of renal cell carcinoma, pheochromocytoma, and prostate cancer, some of which harbor a distinctive chromosomal translocation, gene loss, or mutation. We illustrate applications of immunohistochemistry for differential diagnosis of needle core renal biopsies, intraductal carcinoma of the prostate, and amyloidosis and cite encouraging results from early studies using targeted gene expression panels to predict recurrence after prostate cancer surgery. At our institution, pathologists are working closely with urologic surgeons and interventional radiologists to explore the use of intraoperative frozen sections for margins and nerve sparing during robotic prostatectomy, to pioneer minimally invasive videoscopic inguinal lymphadenectomy, and to refine image-guided needle core biopsies and cryotherapy of prostate cancer as well as blue-light/fluorescence cystoscopy. This collaborative, multidisciplinary approach enhances clinical management and research, and optimizes the care of patients with urologic disorders.

Systematic analysis of telomere length and somatic alterations in 31 cancer types

Cancer cells survive cellular crisis through telomere maintenance mechanisms. We report telomere lengths in 18,430 samples, including tumors and non-neoplastic samples, across 31 cancer types. Telomeres were shorter in tumors than in normal tissues and longer in sarcomas and gliomas than in other cancers. Among 6,835 cancers, 73% expressed telomerase reverse transcriptase (TERT), which was associated with TERT point mutations, rearrangements, DNA amplifications and transcript fusions and predictive of telomerase activity. TERT promoter methylation provided an additional deregulatory TERT expression mechanism. Five percent of cases, characterized by undetectable TERT expression and alterations in ATRX or DAXX, demonstrated elongated telomeres and increased telomeric repeat-containing RNA (TERRA). The remaining 22% of tumors neither expressed TERT nor harbored alterations in ATRX or DAXX. In this group, telomere length positively correlated with TP53 and RB1 mutations. Our analysis integrates TERT abnormalities, telomerase activity and genomic alterations with telomere length in cancer.

A novel diagnostic method of Raman spectroscopy for malignant pheochromocytoma/paraganglioma

Raman spectroscopy, a potential tool in diagnosis of malignant pheochromocytoma/paraganglioma.