Abdominal visceral lesions in von Hippel-Lindau disease: incidence and clinical behavior of pancreatic and adrenal lesions at a single center

Hypoxia signaling pathway: A central mediator in endocrine tumors

Adequate oxygen levels are essential for the functioning and maintenance of biological processes in virtually every cell, albeit based on specific need. Thus, any change in oxygen pressure leads to modulated activation of the hypoxia pathway, which affects numerous physiological and pathological processes, including hematopoiesis, inflammation, and tumor development. The Hypoxia Inducible Factors (HIFs) are essential transcription factors and the driving force of the hypoxia pathway; whereas, their inhibitors, HIF prolyl hydroxylase domain (PHDs) proteins are the true oxygen sensors that critically regulate this response. Recently, we and others have described the central role of the PHD/HIF axis in various compartments of the adrenal gland and its potential influence in associated tumors, including pheochromocytomas and paragangliomas. Here, we provide an overview of the most recent findings on the hypoxia signaling pathway in vivo, including its role in the endocrine system, especially in adrenal tumors.

What Have We Learned from Molecular Biology of Paragangliomas and Pheochromocytomas?

Recent advances in molecular genetics and genomics have led to increased understanding of the aetiopathogenesis of pheochromocytomas and paragangliomas (PPGLs). Thus, pan-genomic studies now provide a comprehensive integrated genomic analysis of PPGLs into distinct molecularly defined subtypes concordant with tumour genotypes. In addition, new embryological discoveries have refined the concept of how normal paraganglia develop, potentially establishing a developmental basis for genotype-phenotype correlations for PPGLs. The challenge for modern pathology is to translate these scientific discoveries into routine practice, which will be based largely on histopathology for the foreseeable future. Here, we review recent progress concerning the cell of origin and molecular pathogenesis of PPGLs, including pathogenetic mechanisms, genetic susceptibility and molecular classification. The current roles and tools of pathologists are considered from a histopathological perspective, including differential diagnoses, genotype-phenotype correlations and the use of immunohistochemistry in identifying hereditary predisposition and validating genetic variants of unknown significance. Current and potential molecular prognosticators are also presented with the hope that predictive molecular biomarkers will be integrated into risk stratification scoring systems to assess the metastatic potential of these intriguing neoplasms and identify potential drug targets.

Pheochromocytoma/Paraganglioma: Is This a Genetic Disorder?

Pheochromocytomas and paragangliomas (PCC/PGL) are neuroendocrine tumors of the adrenal medulla and extra-adrenal ganglia which often over-secrete catecholamines leading to cardiovascular morbidity and even mortality. These unique tumors have the highest heritability of all solid tumor types with up to 35-40% of patients with PCC/PGL having a germline predisposition. PURPOSE OF REVIEW: To review the germline susceptibility genes and clinical syndromes associated with PCC/PGL. RECENT FINDINGS: There are over 12 PCC/PGL susceptibility genes identified in a wide range of pathways. Each gene is associated with a clinical syndrome with varying penetrance for both primary and metastatic PCC/PGL and often includes increased risk for additional tumors besides PCC/PGL. Patients with sporadic or hereditary PCC/PGL should be monitored for life given the risk of multiple primary tumors, recurrence, and metastatic disease. All patients with PCC/PGL should be referred for consideration for clinical genetic testing given the high heritability of disease.

Von Hippel-Lindau Disease With Multi-Organ Involvement: A Case Report and 8-Year Clinical Course With Follow-Up

Patient: Female, 31

Final Diagnosis: Von Hippel-Lindau disease

Symptoms: Abdominal pain

Medication: —

Clinical Procedure: Splenectomy

Specialty: Oncology

Acinar Cell Cystadenoma - a Rarity in Advanced von Hippel-Lindau Disease: A Case Report

Background

Von Hippel-Lindau (VHL) disease may occur at various localisations which can be both intra- and extrapancreatic as well as challenging to diagnose by medical imaging.

Case Report

A positron emission tomography/magnetic resonance imaging in a 40-year-old woman was performed to monitor a haemangioblastoma. Additionally, it showed findings which were considered to be a pancreatic neuroendocrine tumour (pNET) and retroumbilical metastasis. The suspected metastasis was laparoscopically resected; however, pathological evaluation did not lead to a clear categorisation. Consequently, the pancreatic head was resected in which a pNET and various acinar cell cystadenomas were found.

Conclusion

Diagnostic and therapy of advanced VHL disease can be difficult; if in doubt, a surgical approach may establish clarity.

Pancreatic manifestations in von Hippel-Lindau disease: A case report

INTRODUCTION

Pancreatic manifestations in Von Hippel-Lindau (VHL) disease can present as a multitude of forms, and their management can be challenging.

PRESENTATION OF THE CASE

A 66-year-old woman presented with increasing abdominal girth without other associated symptoms of nausea, vomiting, abdominal pain, weight-loss, and jaundice. Her medical and surgical histories were significant for type II diabetes, cerebral tumor resection, bilateral nephrectomies, and laser photocoagulation of retinal hemangiomas. Computed tomography (CT) of the abdomen showed a massive multi-cystic lesion in the pancreas and the patient was referred to our hepatopancreatic biliary center.

DISCUSSION

The findings on the subsequent cross-sectional MRI imaging signified pancreatic manifestations in VHL disease.

CONCLUSION

The management of VHL disease-associated benign pancreatic cystic lesions involves interval monitoring with cross-sectional imaging for malignant changes/development.

Long-term Prognosis of Resected Pancreatic Neuroendocrine Tumors in von Hippel-Lindau Disease Is Favorable and Not Influenced by Small Tumors Left in Place

BACKGROUND

Management of pancreatic neuroendocrine tumors (PNETs) associated with von Hippel-Lindau disease (VHL) is challenging because of the malignant potential and difficulty in predicting prognosis.

OBJECTIVE

Compare the long-term outcome of resected VHL-PNET and sporadic PNET.

METHODS

Data of all patients with VHL (n = 23) operated on for nonmetastatic PNET were reviewed. Patient characteristics and recurrence-free survival rates were compared with those in patients operated on for sporadic PNET, matched for tumor size, stage, and Ki-67 index.

RESULTS

Patients in both groups had similar demographic characteristics, except that patients with VHL were younger (36 vs 56 years, P < 0.0001). Median tumor size was 30 mm. Median Ki-67 index was 3% and 4% in the VHL and sporadic groups (P = 0.95), respectively, and lymph node metastases were present in 43% and 30% of cases, respectively (P = 0.45). Sixteen (70%) patients with VHL had multiple PNET; lesions less than 15 mm were left in place in 11 patients. Median postoperative follow-up was 107 months (interquartile range, 57-124 months) and 71 months (interquartile range, 58-131 months) in the VHL and control groups, respectively. Median recurrence-free survival could not have been estimated in the VHL group due to the low number of events (hazard ratio, 5.6; 95% confidence interval, 1.4-22.6; P = 0.013). Five patients with VHL died (3 from VHL-related tumors including 1 from PNET), whereas only one control patient died due to unrelated causes.

CONCLUSIONS

The long-term outcome of resected VHL-PNET is better than that of sporadic PNET. PNET less than 15 mm left in place did not progress. A parenchyma-sparing surgical strategy seems appropriate in patients with VHL-PNET, who may develop more life-threatening tumors of other organs.

Pheochromocytomas and Paragangliomas: Clinical and Genetic Approaches

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are neuroendocrine tumors derived from the chromaffin tissue. Diagnosis of these tumors is extremely important as they are linked to the hypertension syndrome with great cardiovascular morbidity and mortality. A great majority of PCCs and PGLs are sporadic and benign tumors; however, the classic idea of 10% exception of these features is changing. The description of new genes linked to familial forms of PCC/PGLs, such as succinate dehydrogenase (SDH) complex subunits, KIF1Bβ, EGLN1, TMEM127, and MAX, added to the well-known PCC familial syndrome (MEN2, VHL, and neurofibromatosis type 1) presents new challenges for diagnosis. In this review, we discuss the diversity of clinical and genetic approaches to this syndrome as well the diverse criteria that should guide genetic investigation.

Familial pheochromocytomas and paragangliomas

Pheochromocytomas and paragangliomas are neural crest cell tumors of the adrenal medulla and parasympathetic/sympathetic ganglia, respectively, that are often associated with catecholamine production. Genetic research over the years has led to our current understanding of the association 13 susceptibility genes with the development of these tumors. Most of the susceptibility genes are now associated with specific clinical presentations, biochemical makeup, tumor location, and associated neoplasms. Recent scientific advances have highlighted the role of somatic mutations in the development of pheochromocytoma/paraganglioma as well as the usefulness of immunohistochemistry in triaging genetic testing. We can now approach genetic testing in pheochromocytoma/paraganglioma patients in a very organized scientific way allowing for the reduction of both the financial and emotional burden on the patient. The discovery of genetic predispositions to the development of pheochromocytoma/paraganglioma not only facilitates better understanding of these tumors but will also lead to improved diagnosis and treatment of this disease.

Pancreatic involvement in Japanese patients with von Hippel-Lindau disease: results of a nationwide survey

BACKGROUND

The frequency and prognosis of pancreatic endocrine tumors (PNET)/pancreatic cystic tumors (PCT) in Japanese patients with von Hippel-Lindau disease (VHL) are still open to question.

METHODS

We conducted the first nationwide epidemiological study of VHL disease in Japan to elucidate this question. Data on 377 VHL patients (PNET, 53; PCT, 152) were reported, and then their clinical characteristics were analyzed.

RESULTS

PNET was found in 14.1 % and PCT in 40.3 %; 4.5 % had both. The onset of PNET and PCT mostly occurred at 30-39 years of age (median ages, 34 and 33 years, respectively). Metastasis was observed in 7.5 % of PNET patients at diagnosis, and 64.2 % underwent surgery including enucleation, partial and total pancreatectomy, and bypass surgery. Two patients received non-surgical therapies. No PNET-related deaths were observed. In PCT patients, no metastasis was observed at diagnosis, and 9.2 % underwent surgery or drainage. According to the classification system without or with adrenal pheochromocytoma, the VHL patients studied herein were subdivided into 313 (83 %) with VHL type 1 and 64 (17 %) with VHL type 2; 29 (9.3 %) and 24 (37.5 %) patients had PNET with VHL type 1 and 2, suggesting that patients with VHL type 2 were significantly more related to PNET than those with VHL type 1 (P < 0.01).

CONCLUSIONS

This study showed no significant difference in the epidemiology of pancreatic involvement between Japanese and non-Japanese VHL patients. Concerning the prognosis, follow-up study is needed.

Paragangliomas/Pheochromocytomas: clinically oriented genetic testing

Paragangliomas are rare neuroendocrine tumors that arise in the sympathetic or parasympathetic nervous system. Sympathetic paragangliomas are mainly found in the adrenal medulla (designated pheochromocytomas) but may also have a thoracic, abdominal, or pelvic localization. Parasympathetic paragangliomas are generally located at the head or neck. Knowledge concerning the familial forms of paragangliomas has greatly improved in recent years. Additionally to the genes involved in the classical syndromic forms: VHL gene (von Hippel-Lindau), RET gene (Multiple Endocrine Neoplasia type 2), and NF1 gene (Neurofibromatosis type 1), 10 novel genes have so far been implicated in the occurrence of paragangliomas/pheochromocytomas: SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, MAX, EGLN1, HIF2A, and KIF1B. It is currently accepted that about 35% of the paragangliomas cases are due to germline mutations in one of these genes. Furthermore, somatic mutations of RET, VHL, NF1, MAX, HIF2A, and H-RAS can also be detected. The identification of the mutation responsible for the paraganglioma/pheochromocytoma phenotype in a patient may be crucial in determining the treatment and allowing specific follow-up guidelines, ultimately leading to a better prognosis. Herein, we summarize the most relevant aspects regarding the genetics and clinical aspects of the syndromic and nonsyndromic forms of pheochromocytoma/paraganglioma aiming to provide an algorithm for genetic testing.

Successful treatment of paraganglioma with sorafenib: a case report and brief review of the literature

Introduction

To date, no effective systemic therapies have been made available for paraganglioma. However, multiple mutations in susceptibility genes have been identified that are potential targets for sorafenib, an oral multitargeted tyrosine-kinase inhibitor.

Case presentation

We report the case of a 69-year-old Chinese man with mediastinal paraganglioma that had metastasized to the bone. The paraganglioma responded to sorafenib, a novel multi-tyrosine kinase inhibitor that targets angiogenesis, the Raf-kinase pathway, the platelet-derived growth factor Ret, and c-Kit. The patient was diagnosed as having paraganglioma after biopsy of the mediastinal mass. We first treated the patient with radiotherapy. Then he tolerated an etoposide-and-cisplatin chemotherapy regimen. Subsequently, he received 6 months of maintenance treatment with sorafenib (400 mg twice daily). A dramatic reduction in tumor volume was observed. At present, the patient has achieved a partial response, and his clinical status remains unchanged.

Conclusion

We suggest that sorafenib should be further investigated in the management of patients with paraganglioma.

Pancreatic cyst development: insights from von Hippel-Lindau disease

Pancreatic cysts are a heterogeneous group of lesions, which can be benign or malignant. Due to improved imaging techniques, physicians are more often confronted with pancreatic cysts. Little is known about the origin of pancreatic cysts in general. Von Hippel-Lindau (VHL) disease is an atypical ciliopathy and inherited tumor syndrome, caused by a mutation in the VHL tumor suppressor gene encoding the VHL protein (pVHL). VHL patients are prone to develop cysts and neuroendocrine tumors in the pancreas in addition to several other benign and malignant neoplasms. Remarkably, pancreatic cysts occur in approximately 70% of VHL patients, making it the only hereditary tumor syndrome with such a discernible expression of pancreatic cysts. Cellular loss of pVHL due to biallelic mutation can model pancreatic cystogenesis in other organisms, suggesting a causal relationship. Here, we give a comprehensive overview of various pVHL functions, focusing on those that can potentially explain pancreatic cyst development in VHL disease. Based on preclinical studies, cilia loss in ductal cells is probably an important early event in pancreatic cyst development.

Pancreatic lesions in von Hippel-Lindau disease? A systematic review and meta-synthesis of the literature

BACKGROUND

von Hippel-Lindau (vHL) disease is a rare condition that leads to characteristic lesions within many different body systems. Pancreatic manifestations of vHL cover a wide spectrum of pathologies, and thus, accurate characterization and management is critical.

METHODS

A comprehensive and systematic text word and MeSH search of the medical literature was performed to identify studies where information regarding the prevalence, clinical characteristics, and management recommendations could be extracted.

RESULTS

Eleven studies were identified but 2 studies utilized the same data set. Of the 10 remaining studies, a total of 1,442 patients with vHL were available for analysis. Four hundred and twenty patients were examined for any type of pancreatic lesion, 362 for simple cysts or serous cystadenomas (SCAs), and 1,442 for neuroendocrine tumors (NETs). Of the 420 assessed for any pancreatic manifestation of vHL, 252 (60%) had a pancreatic lesion identified. Simple cysts that present as the sole manifestation of pancreatic disease were common and found in 169 of 362 (47%) patients. These are usually asymptomatic and do not normally require intervention. SCAs were reported in 39 of 362 (11%) patients and followed a similar benign course; resection is acceptable in symptomatic patients. NETs were identified in 211 of 1,442 (15%) patients, and 27 of 1,442 (2%) lesions behaved malignantly. Management of NETs depends on size, doubling time, and underlying genetics. Renal cell carcinoma is a characteristic in vHL, but there were no cases of pancreatic metastases identified from the included studies. Adenocarcinomas of the pancreas are not pathogenically linked to vHL.

CONCLUSIONS

This review highlights the wide spectrum and high prevalence of pancreatic lesions in vHL. Simple cysts and SCAs are benign, but NETs require careful observation due to their malignant potential.

Pheochromocytoma and paraganglioma: understanding the complexities of the genetic background

Pheochromocytomas and paragangliomas (PCC/PGL) are tumors derived from the adrenal medulla or extra-adrenal ganglia, respectively. They are rare and often benign tumors that are associated with high morbidity and mortality due to mass effect and high circulating catecholamines. Although most PCCs and PGLs are thought to be sporadic, over one third are associated with 10 known susceptibility genes. Mutations in three genes causing well characterized tumor syndromes are associated with an increased risk of developing PCCs and PGLs, including VHL (von Hippel-Lindau disease), NF1 (Neurofibromatosis Type 1), and RET (Multiple Endocrine Neoplasia Type 2). Mutations in any of the succinate dehydrogenase (SDH) complex subunit genes (SDHA, SDHB, SDHC, SDHD) can lead to PCCs and PGLs with variable penetrance, as can mutations in the subunit cofactor, SDHAF2. Recently, two additional genes have been identified, TMEM127 and MAX. Although these tumors are rare in the general population, occurring in two to eight per million people, they are more commonly associated with an inherited mutation than any other cancer type. This review summarizes the known germline and somatic mutations leading to the development of PCC and PGL, as well as biochemical profiling for PCCs/PGLs and screening of mutation carriers.

Pancreatic manifestations of von Hippel-Lindau disease

Von Hippel-Lindau disease is an uncommon, multisystem, multitumor disorder that can present in sporadic form but is more commonly inherited as an autosomal-dominant disease with high penetrance. Affected patients are at increased risk for developing multiple synchronous or metachronous benign or malignant, cystic, and vascular neoplasms of various organs. The characteristic neoplasms associated with von Hippel-Lindau are hemangioblastoma of the central nervous system and retina, clear cell renal cell carcinoma, and pheochromocytoma, but other lesions are well recognized. Pancreatic lesions, both primary and metastatic, are common, and several differential diagnostic possibilities must be considered.

Surgical management of nonmultiple endocrine neoplasia endocrinopathies: state-of-the-art review

The development of genetic testing has given patients with familial endocrine diseases the opportunity to be identified earlier in life. The importance of this technological advancement cannot be underestimated, as some of these heritable diseases have significant potential for malignancy. This article focuses on the identification and surgical management of familial endocrinopathies of the thyroid, parathyroid, adrenal glands, and pancreas. Familial endocrinopathies discussed include hereditary nonmedullary carcinoma of the thyroid, Cowden disease, familial adenomatous polyposis, Carney complex, Werner syndrome, familial medullary thyroid carcinoma, Pendred syndrome, hereditary hyperparathyroidism jaw-tumor syndrome, familial isolated hyperparathyroidism, Beckwith- Wiedemann syndrome, Li-Fraumeni syndrome, neurofibromatosis I, von Hippel-Lindau disease, and tuberous sclerosis.

Inherited pancreatic endocrine tumor syndromes: advances in molecular pathogenesis, diagnosis, management, and controversies

Pancreatic endocrine tumors (PETs) can occur as part of 4 inherited disorders, including Multiple Endocrine Neoplasia type 1 (MEN1), von Hippel-Lindau disease (VHL), neurofibromatosis 1 (NF-1) (von Recklinghausen disease), and the tuberous sclerosis complex (TSC). The relative frequency with which patients who have these disorders develop PETs is MEN1>VHL>NF-1>TSC. Over the last few years, there have been major advances in the understanding of the genetics and molecular pathogenesis of these disorders as well in the localization and the medical and surgical treatment of PETs in such patients. The study of PETs in these disorders not only has provided insights into the possible pathogenesis of sporadic PETs but also has presented several unique management and treatment issues, some of which are applicable to patients with sporadic PETs. Therefore, the study of PETs in these uncommon disorders has provided valuable insights that, in many cases, are applicable to the general group of patients with sporadic PETs. In this article, these areas are reviewed briefly along with the current state of knowledge of the PETs in these disorders, and the controversies that exist in their management are summarized briefly and discussed.

Pancreatic neuroendocrine tumours

Pancreatic neuroendocrine tumours are rare tumours ( approximately 1/100,00 population/year) of which 60% are non-functioning. Except for insulinoma all types are malignant in >50% of cases. In multiple endocrine neoplasia (MEN)1, pancreatic neuroendocrine tumours occur in 40-80% of patients and are mostly non-functioning tumours or gastrinomas. Insulinomas are benign in approximately 90%, solitary in 95% of sporadic cases whilst multiple in 90% of MEN1 patients. In contrast approximately 50% gastrinomas and the majority of non-functioning pancreatic neuroendocrine tumours are malignant. Pancreatic neuroendocrine tumours occur in 10-15% of patients with Von Hippel-Lindau (VHL) and are frequently multiple (>30%). Surgical excision is a key aspect of treatment for all cases of sporadic gastrinoma and if >2.5 cm in MEN1. Insulinomas are enucleated if solitary and may require pancreatectomy if multiple. Non-functioning tumours should also be resected if sporadic and if >2 cm in MEN1 or if >2-3 cm in VHL. Tumours <1cm require yearly follow-up by CT or MRI from an early age in VHL. The local treatment for liver metastases is now well established and options include liver resection, chemoembolisation and radiofrequency ablation. Systemic therapies have also been better defined and include radionuclide therapy against somatostatin receptors or MIBG and chemotherapy especially for poorly differentiated tumours. A number of novel agents are currently in clinical development.

Pheochromocytoma: advances in genetics, diagnosis, localization, and treatment

Pheochromocytomas are rare, catecholamine-secreting tumors arising most frequently in the chromaffin cells of the adrenal glands. Recent studies have suggested that genetic mutations are more frequent than previously appreciated in patients with these lesions. Advances continue to be made not only in the genetic evaluation of these patients but also in the biochemical confirmation and tumor localization. Surgery remains the definitive treatment, and advances in laparoscopic techniques as well as cortical-sparing procedures have reduced the morbidity associated with tumor resection.