Clustering of features of von Hippel-Lindau syndrome: evidence for a complex genetic locus

Von Hippel-Lindau disease with ocular and multiple systemic findings

Von Hippel-Lindau is a rare genetic disease that is inherited as an autosomal dominant pattern. Characteristics of this disease include multiple vascularised tumours, particularly cerebellar, retinal and/or visceral. The disease can occur at any age with retinal haemangioblastomas as one of the earliest manifestations. The gold-standard investigation for cerebral haemangioblastomas is MRI or cerebral CT and for retinal haemangioblastomas is fluorescein angiography. We present the case of a woman in her late 30s who reported a primary concern of diminished vision in both eyes for the past 6 months. Fundus examination revealed blurred disc margins, optic nerve head haemangioblastomas and peripheral retinal haemangioblastomas in both eyes. Blood investigations showed polycythaemia. A 24-hour urine protein report showed increased levels. MRI showed multiple cystic lesions in the posterior fossa, on the right optic nerve in the optic canal, multiple cortical cysts in both kidneys and a soft tissue space-occupying lesion.

Genetics, Pathophysiology, and Current Challenges in Von Hippel-Lindau Disease Therapeutics

This review article focuses on von Hippel-Lindau (VHL) disease, a rare genetic disorder characterized by the development of tumors and cysts throughout the body. It discusses the following aspects of the disease.

GENETICS

VHL disease is caused by mutations in the VHL tumor suppressor gene located on chromosome 3. These mutations can be inherited or occur spontaneously. This article details the different types of mutations and their associated clinical features.

PATHOPHYSIOLOGY

The underlying cause of VHL disease is the loss of function of the VHL protein (pVHL). This protein normally regulates hypoxia-inducible factors (HIFs), which are involved in cell growth and survival. When pVHL is dysfunctional, HIF levels become elevated, leading to uncontrolled cell growth and tumor formation.

CLINICAL MANIFESTATIONS

VHL disease can affect various organs, including the brain, spinal cord, retina, kidneys, pancreas, and adrenal glands. Symptoms depend on the location and size of the tumors.

DIAGNOSIS

Diagnosis of VHL disease involves a combination of clinical criteria, imaging studies, and genetic testing.

TREATMENT

Treatment options for VHL disease depend on the type and location of the tumors. Surgery is the mainstay of treatment, but other options like radiation therapy may also be used.

CHALLENGES

This article highlights the challenges in VHL disease management, including the lack of effective therapies for some tumor types and the need for better methods to monitor disease progression. In conclusion, we emphasize the importance of ongoing research to develop new and improved treatments for VHL disease.

Late-Onset Manifestations of Von Hippel-Lindau Syndrome: A Case Report

Von Hippel-Lindau (VHL) syndrome is characterized by a range of tumors including phaeochromocytomas, pancreatic adenomas, cerebellar haemangioblastomas, and renal cell carcinomas. A 50-year-old male presented with a three-week history of headache. Additionally, the patient exhibited signs of hypertension. Ultrasonography (USG) abdomen and pelvis showed a solid mass lesion in the left adrenal gland, iso-echoic to the renal cortex. On contrast-enhanced computed tomography (CECT) of the brain, a well-defined solid cystic lesion was seen in the left posterior cerebellar hemisphere. Small nodular enhancing lesions were seen in the right cerebellar hemisphere. On further imaging with MRI brain contrast, the lesions in the cerebellum were diagnosed as multifocal hemangioblastomas. Laboratory investigations revealed elevated urinary metanephrines and normetanephrine, suggesting pheochromocytoma. Based on radiological and biochemical investigations, with the features of cerebellar haemangioblastomas and pheochromocytoma, a diagnosis of VHL syndrome was made.

Epidemiology and economic burden of Von Hippel-Lindau Disease-associated central nervous system hemangioblastomas and pancreatic neuroendocrine tumors in the United States

BACKGROUND

To date, real-world evidence around the clinical and economic burden related to von Hippel-Lindau (VHL) disease is limited. Therefore, this study characterized the prevalence, healthcare resource utilization (HRU), and economic burden of von Hippel-Lindau-associated central nervous system hemangioblastoma (VHL-CNS-Hb) and pancreatic neuroendocrine tumors (VHL-pNET) in the United States (US).

METHODS

Patients with VHL-CNS-Hb or VHL-pNET were identified from Optum's de-identified Clinformatics® Data Mart Database (2007-2020) and matched 1:5 to control patients without VHL disease or CNS-Hb/pNET. Prevalence rates of VHL-CNS-Hb and VHL-pNET (standardized by age and sex) in 2019 were estimated. HRU and healthcare costs (2020 US dollars) were compared between the VHL-CNS-Hb/VHL-pNET and control cohorts.

RESULTS

In 2019, US prevalence rates of VHL-CNS-Hb and VHL-pNET were estimated to be 1.12 cases per 100,000 (3,678 patients) and 0.12 cases per 100,000 (389 patients), respectively. Patients with VHL-CNS-Hb (N = 220) had more inpatient, outpatient, and emergency department visits and $49,645 higher annual healthcare costs than controls (N = 1,100). Patients with VHL-pNET (N = 20) had more inpatient and outpatient visits and $56,580 higher annual healthcare costs than controls (N = 100). Costs associated with surgical removal of CNS-Hb and pNET were particularly high.

CONCLUSIONS

In this retrospective, claims-based study, both VHL-CNS-Hb and VHL-pNET were associated with substantial HRU and healthcare costs, particularly tumor reduction surgery-related costs. These findings provide important insight for healthcare payers regarding the expected real-world costs that enrollees with VHL-CNS-Hb and VHL-pNET may incur over the course of their disease.

Mutation in Chek2 triggers von Hippel-Lindau hemangioblastoma growth

PURPOSE

Von Hippel-Lindau (VHL) is a rare inherited disease mainly characterized by the growth of tumours, predominantly hemangioblastomas (Hbs) in the CNS and retina, and renal carcinomas. The natural history of VHL disease is variable, differing in the age of onset and its penetrance, even among relatives. Unfortunately, sometimes VHL shows more severe than average: the onset starts in adolescence, and surgeries are required almost every year. In these cases, the factor that triggers the appearance and growth of Hbs usually remains unknown, although additional mutations are suspected.

METHODS

We present the case of a VHL patient whose first surgery was at 13 years of age. Then, along his next 8 years, he has undergone 5 surgeries for resection of 10 CNS Hbs. To clarify this severe VHL condition, DNA from a CNS Hb and white blood cells (WBC) was sequenced using next-generation sequencing technology.

RESULTS

Massive DNA sequencing of the WBC (germ line) revealed a pathogenic mutation in CHEK2 and the complete loss of a VHL allele (both tumour suppressors). Moreover, in the tumour sample, several mutations, in BRAF1 and PTPN11 were found. Familiar segregation studies showed that CHEK2 mutation was in the maternal lineage, while VHL was inherited by paternal lineage.

CONCLUSIONS

Finally, clinical history correlated to the different genotypes in the family, concluding that the severity of these VHL manifestations are due to both, VHL-and-CHEK2 mutations. This case report aims to notice the importance of deeper genetic analyses, in inherited rare diseases, to uncover non-expected mutations.

68Ga-DOTANOC PET/CT for Screening and Surveillance of Von Hippel-Lindau (VHL) disease

Purpose

Hereditary tumor syndrome Von Hippel-Lindau (VHL) disease is characterized by various benign and malignant tumors that are known to express somatostatin receptors (SSTR). We evaluated the role of 68Ga-DOTANOC PET/CT scan in patients with positive germline mutation of the VHL gene, presented initially or on follow-up, for the detection of recurrent or synchronous/metachronous lesions.

Methods

Fourteen patients (8 males; 6 females) with mean age 30 ± 9.86 years were retrospectively analyzed, were tested positive for VHL on gene dosage analysis, and underwent 68 Ga-DOTANOC PET/CT scan for disease evaluation. The number and site of lesions were determined. The tracer uptake was analyzed semi-quantitatively by calculating the maximum standardized uptake values (SUVmax) of lesion.

Results

Four of the 14 patients underwent scan for initial diagnosis as baseline, 6 patients for post-therapy disease status, and 4 patients for initial diagnosis as well as follow-up evaluation of the disease. A total of 67 lesions were detected in 14 patients. The sites of lesions were cerebellar/vertebral/spinal (17; mean SUVmax = 7.85); pancreatic neuroendocrine tumor (NET) (11; mean SUVmax = 20.64); retina (3; mean SUVmax = 10.46); pheochromocytoma (10; mean SUVmax = 16.32); paragangliomas (3; mean SUVmax = 10.65); pancreatic cyst (9; mean SUVmax = 2.54); and renal cyst (8; mean SUVmax = 1.56) and miscellaneous lesions constituted 6 lesions.

Conclusion

Our results show that 68 Ga-DOTANOC PET/CT may be a useful modality for screening and follow-up of associated tumors in patients with germline gene mutation for VHL. It can be used as a one-stop imaging modality for VHL patients and may substitute for separate radiological investigations, making it more convenient for patients in terms of time and cost.

Comprehensive characterization and building of National Registry of von Hippel-Lindau disease in Brazil

BACKGROUND

Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder caused by pathogenic variants in VHL gene. The common manifestations include hemangioblastomas (HB) of the central nervous system (CNS) and retina (RH); pheochromocytoma (PHEO); clear cell renal cell carcinoma (ccRCC); pancreatic and renal cysts (PRC) and pancreatic neuroendocrine neoplasm (PNEN).

METHODS

The first characterization of VHL in Brazil was published in 2003 and included 20 families with a history of VHL. The aim of this study was to expand the previous Brazilian cohort to include more families, as well as to collect prospectively both clinical and molecular characteristics of patients with VHL to build the VHL Brazilian Registry (VHLBR). Patients with VHL were selected through review of data from medical records of experts and from social networks of support for families with VHL in Brazil.

RESULTS

A total of 142 subjects representing 62 unrelated Brazilian families with VHL were registered. The mean age of VHL onset was 28.78 years old and 128 individuals (90.1%) had at least one VHL-related lesion. CNS HB was the most common manifestation occurring in 91 (71%) patients, followed by multiple PRC (48.4%), RH (39.8%), ccRCC (28.9%), PHEO (12.5%) and PNEN (7.8%). Of the 97 subjects whose presence of VHL variants was confirmed, 51 (52.6%) had missense variants, 22 (22.7%) large deletions, 10 (10.3%) frameshift, 7 (7.2%) splice site, 4 (4.1%) nonsense and 3 (3.1%) in-frame deletions. Regarding surveillance, 115 (81%) participants had at least one physician responsible for their outpatient follow-up; however, 69 (60%) of them did not report a regular frequency of tests.

CONCLUSION

We built the largest prospective VHLBR with organized collections of clinical and genetic data from families with VHL, which will be helpful to guide policies for VHL care and oncogenetics in Brazil. Although there have been improvements in diagnosis and clinical screening methods, VHL care in Brazil is still deficient, especially regarding surveillance and regular medical appointments with experts.

Immunological Aspects of Von Hippel-Lindau Disease: A Focus on Neuro-Oncology and Myasthenia Gravis

Von Hippel-Lindau (VHL) disease is an autosomal dominant condition that predisposes affected individuals to a variety of malignant and benign neoplasms. The pathogenetic turning point of this illness is the accumulation of hypoxia-inducible factor (HIF)-1α, a transcription factor of several genes involved in oncogenesis, angiogenesis, tissue regeneration, metabolic regulation, hematopoiesis, and inflammatory responses. From an oncological perspective, increased awareness of the molecular pathways underlying this disease is bringing us closer to the development of specific and targeted therapies. Meanwhile, on the surgical side, improved understanding can help to better identify the patients to be treated and the surgical timing. Overall, pathogenesis research is crucial for developing patient-tailored therapies. One of the actual key topics of interest is the link between the VHL/HIF axis and inflammation. The present study aims to outline the fundamental mechanisms that link VHL disease and immune disorders, as well as to explore the details of the overlap between VHL disease and myasthenia gravis (MG) pathogenetic pathways. As a result, MG becomes a paradigm for autoimmune disorders that might be related with VHL disease.

Epidemiology and Economic Burden of von Hippel-Lindau Disease-Associated Renal Cell Carcinoma in the United States

INTRODUCTION

We developed a claims-based algorithm to identify patients with von Hippel-Lindau disease-associated renal cell carcinoma (VHL-RCC) from a real-world database and quantified the prevalence, healthcare resource utilization (HRU), and healthcare costs of VHL-RCC in the United States (US).

METHODS

Using data from the Optum Clinformatics Data Mart (2007-2020), an algorithm was developed to identify patients with VHL-RCC, who were matched to controls without VHL disease or RCC. VHL-RCC prevalence in 2019 was estimated and standardized to the US population. HRU and costs were compared between patients with VHL-RCC versus controls, and costs associated with tumor reduction procedures were estimated among patients with VHL-RCC. All costs were adjusted to 2020 US dollars.

RESULTS

VHL-RCC prevalence in the US was 0.92 per 100,000 persons, resulting in 3023 estimated patients with VHL-RCC in the US. The VHL-RCC cohort (N = 160) incurred higher rates of inpatient, outpatient, and emergency department visits versus controls (N = 800), translating to $36,450 more in adjusted all-cause annual healthcare costs. By examining only claims with an associated RCC diagnosis, it was estimated that patients with VHL-RCC incurred $21,123 annually in healthcare costs due to RCC management, and the average cost of nephrectomy was $29,313. Among different complications of RCC-related tumor reduction procedures, end-stage renal disease was the costliest, which incurred $65,338 over 6 months postnephrectomy.

CONCLUSION

VHL-RCC was associated with significant HRU and healthcare costs, including those related to tumor surgeries. This study underscores the importance of novel therapies that can reduce the clinical burden and medical intervention costs of VHL-RCC.

Tumorigenesis Mechanisms Found in Hereditary Renal Cell Carcinoma: A Review

Renal cell carcinoma is a heterogenous cancer composed of an increasing number of unique subtypes each with their own cellular and tumor behavior. The study of hereditary renal cell carcinoma, which composes just 5% of all types of tumor cases, has allowed for the elucidation of subtype-specific tumorigenesis mechanisms that can also be applied to their sporadic counterparts. This review will focus on the major forms of hereditary renal cell carcinoma and the genetic alterations contributing to their tumorigenesis, including von Hippel Lindau syndrome, Hereditary Papillary Renal Cell Carcinoma, Succinate Dehydrogenase-Deficient Renal Cell Carcinoma, Hereditary Leiomyomatosis and Renal Cell Carcinoma, BRCA Associated Protein 1 Tumor Predisposition Syndrome, Tuberous Sclerosis, Birt-Hogg-Dubé Syndrome and Translocation RCC. The mechanisms for tumorigenesis described in this review are beginning to be exploited via the utilization of novel targets to treat renal cell carcinoma in a subtype-specific fashion.

The Clinical and Molecular Features in the VHL Renal Cancers; Close or Distant Relatives with Sporadic Clear Cell Renal Cell Carcinoma?

Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited cancer syndrome caused by germline mutations in the VHL tumor suppressor gene, characterized by the susceptibility to a wide array of benign and malign neoplasms, including clear-cell renal cell carcinoma. Moreover, VHL somatic inactivation is a crucial molecular event also in sporadic ccRCCs tumorigenesis. While systemic biomarkers in the VHL syndrome do not currently play a role in clinical practice, a new promising class of predictive biomarkers, microRNAs, has been increasingly studied. Lots of pan-genomic studies have deeply investigated the possible biological role of microRNAs in the development and progression of sporadic ccRCC; however, few studies have investigated the miRNA profile in VHL patients. Our review summarize all the new insights related to clinical and molecular features in VHL renal cancers, with a particular focus on the overlap with sporadic ccRCC.

Systemic Therapy Development in Von Hippel-Lindau Disease: An Outsized Contribution from an Orphan Disease

Over the last several decades, an improved understanding of von Hippel-Lindau disease and its underlying biology has informed the successful development of numerous anti-cancer agents, particularly for the treatment of advanced renal cell carcinoma. Most recently, this has culminated in the first regulatory approval for a systemic therapy for VHL disease-associated neoplasms. This review will trace the clinical development of systemic therapies for VHL disease and additionally highlight anticipated challenges and opportunities for future VHL systemic therapy.

Multidisciplinary integrated care pathway for von Hippel-Lindau disease

BACKGROUND

Clinical pathways are care plans established to describe essential steps in the care of patients with a specific clinical problem. They translate (inter)national guidelines into local applicable protocols and clinical practice. The purpose of this article is to establish a multidisciplinary integrated care pathway for specialists and allied health care professionals in caring for individuals with von Hippel-Lindau (VHL) disease.

METHODS

Using a modified Delphi consensus-making process, a multidisciplinary panel from 5 Dutch University Medical Centers produced an integrated care pathway relating to the provision of care for patients with VHL by medical specialists, specialized nurses, and associated health care professionals. Patient representatives cocreated the pathway and contributed quality criteria from the patients' perspective.

RESULTS

The panel agreed on recommendations for the optimal quality of care for individuals with a VHL gene mutation. These items were the starting point for the development of a patient care pathway. With international medical guidelines addressing the different VHL-related disorders, this article presents a patient care pathway as a flowchart that can be incorporated into VHL expertise clinics or nonacademic treatment clinics.

CONCLUSIONS

Medical specialists (internists, urologists, neurosurgeons, ophthalmologists, geneticists, medical oncologists, neurologists, gastroenterologists, pediatricians, and ear-nose-throat specialists) together with specialized nurses play a vital role alongside health care professionals in providing care to people affected by VHL and their families. This article presents a set of consensus recommendations, supported by organ-specific guidelines, for the roles of these practitioners in order to provide optimal VHL care. This care pathway can form the basis for the development of comprehensive, integrated pathways for multiple neoplasia syndromes.

von Hippel-Lindau disease: Updated guideline for diagnosis and surveillance

von Hippel Lindau disease (vHL) is caused by a hereditary predisposition to multiple neoplasms, especially hemangioblastomas in the retina and CNS, renal cell carcinomas (RCC), pheochromocytomas, neuroendocrine pancreatic tumours (PNET) and endolymphatic sac tumours. Evidence based approaches are needed to ensure an optimal clinical care, while minimizing the burden for the patients and their families. This guideline is based on evidence from the international vHL literature and extensive research of geno- and phenotypic characteristics, disease progression and surveillance effect in the national Danish vHL cohort. We included the views and preferences of the Danish vHL patients, ensured consensus among Danish experts and compared with international recommendations. RECOMMENDATIONS: vHL can be diagnosed on clinical criteria, only; however, in most cases the diagnosis can be supported by identification of a pathogenic or likely pathogenic variant in VHL. Surveillance should be initiated in childhood in persons with, or at risk of, vHL, and include regular examination of the retina, CNS, inner ear, kidneys, neuroendocrine glands, and pancreas. Treatment of vHL manifestations should be planned to optimize the chance of cure, without unnecessary sequelae. Most manifestations are currently treated by surgery. However, belzutifan, that targets HIF-2α was recently approved by the U.S. Food and Drug Administration (FDA) for adult patients with vHL-associated RCC, CNS hemangioblastomas, or PNETs, not requiring immediate surgery. Diagnostics, surveillance, and treatment of vHL can be undertaken successfully by experts collaborating in multidisciplinary teams. Systematic registration, collaboration with patient organisations, and research are fundamental for the continuous improvement of clinical care and optimization of outcome with minimal patient inconvenience.

Evaluation of tumour surveillance protocols and outcomes in von Hippel-Lindau disease in a national health service

Background

Von Hippel-Lindau (VHL) disease is an inherited tumour predisposition syndrome and a paradigm for the importance of early diagnosis and surveillance. However, there is limited information on the “real world” management of VHL disease.

Methods

A national audit of VHL disease in the United Kingdom.

Results

VHL disease was managed mostly via specialist clinics coordinated through regional clinical genetics services (but frequently involving additional specialties). Over the study period, 19 genetic centres saw 842 individuals (393 males, 449 females) with a clinical and/or molecular diagnosis of VHL disease and 74 individuals (35 male, 39 female) with a prior risk of 50% (affected parent). All centres offered retinal, central nervous system and abdominal surveillance to affected individuals and at-risk relatives though surveillance details differed between centres (but complied with international recommendations). Renal lesions detected on the first surveillance scan were, on average, larger than those detected during subsequent scans and the larger the diameter at detection the greater the likelihood of early intervention.

Conclusions

In a state-funded health care system individuals with a rare inherited cancer predisposition syndrome are generally able to access appropriate surveillance and patient management is improved compared to historical data. The “real world” data from this study will inform the future development of VHL management protocols.

Retinal angioma of Von hippel-lindau disease: A case report

Introduction

Von Hippel–Lindau disease (VHL), also known as Von Hippel–Lindau syndrome, is a rare genetic disorder with multisystem involvement. It is characterised by the development of multiple vascularised tumours, particularly cerebellar, retinal and/or visceral. The disease can occur at any age and usually starts with retinal hemangioblastomas.

Case report

We report the case of a 45-year-old female patient with no particular pathological history, who. consulted the ophthalmology department for a change of optical correction.

The funds examination showed an uncomplicated bilateral hemangioma with no other associated signs. Fluorescein angiography confirmed the diagnosis by showing in the left eye a multiple retinal hemangioma visible in the mid-periphery facing the branches of the superior temporal arches. The brain MRI showed a multifocal hemangioblastoma in the posterior cerebral fossa. A renal ultrasound returned normal. The patient had undergone photocoagulation of the retinal lesions to avoid any complications.

Discussion

The German ophthalmologist Eugen von Hippel first described angiomas in the eye. The term Von Hippel–Lindau disease was first used in 1936; however, its use became common only in the 1970s.

Tumours called hemangioblastomas are characteristic of von Hippel-Lindau syndrome. These growths are made of newly formed blood vessels and occurs in the periphery of the retina. Spontaneous progression occurs leading to visual impairment as a result of maculopathy or exudative retinal detachment.

Early recognition and treatment of specific manifestations of VHL can substantially decrease complications and improve quality of life.

Conventional treatment of the retinal hemangioblastomas is laser photocoagulation or cryotherapy depending on the location and size of the lesions. It must be based on the patient's visual symptoms and tumor progression.

Conclusion

Management of patients with VHL disease often requires a multidisciplinary approach. The role of the ophthalmologist is important in the management of this condition since the ocular involvement may be indicative of the disease.

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Von Hippel Lindau disease is a systemic condition whose initial signs are usually ocular.

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The ocular lesion is generally one of the major and revealing manifestations of the disease.

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The risk of progression to blindness is important, making early detection and treatment highly beneficial.

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The role of the ophthalmologist is crucial in the management of this condition.

e Santos G, Araujo Tuma Santos C. Anesthetic Management for Resection of a Cerebellar Hemangioblastoma Leading to Brainstem Compression in a Patient With Von Hippel-Lindau Disease

Von Hippel-Lindau (VHL) disease is a complex genetic syndrome characterized by multisystemic vascular neoplastic disorder. The affected population tends to develop tumors mainly involving the central nervous system, adrenal glands, pancreas, and kidneys. We describe anesthetic management for the resection of a cerebellar mass compressing the brainstem in a recently diagnosed 25-year-old female patient with a history of von Hippel-Lindau (VHL) syndrome. An uneventful occipital craniectomy for cerebellar tumor resection was performed under total intravenous anesthesia, without complications. The patient was discharged home on postoperative day five. This case depicts a situation in which a brainstem compressing lesion needs to be addressed urgently, and the pharmacological neuroprotective technique utilized for this procedure.

rs779805 Von Hippel-Lindau Gene Polymorphism Induced/Related Polycythemia Entity, Clinical Features, Cancer Association, and Familiar Characteristics

Increased red blood cell count may result from primary erythrocytosis (polycythemia vera), but it is often due to secondary causes with increased erythropoietin levels. Secondary erythrocytosis may also be congenital due to different gene mutations of hemoglobin, hemoglobin stabilization proteins, EPO receptors, or oxygen sensing pathways. Von Hippel- Lindau gene mutation causes altered tissue oxygen sensation in VHL disease, usually with normal hemoglobin. Germline VHL mutations associate with classical VHL disease and represent genetic susceptibility for pheochromocytoma. VHL polymorphisms are mostly considered an innocent phenomenon. Still, some data indicate that these polymorphisms are not always harmless and can occur with prostate, renal, and colon cancer or even with isolated erythrocytosis. Seventy-eight patients referred to our department with elevated hemoglobin were screened for VHL mutations. There were no classical somatic VHL mutations. However, we found heterozygous (GA) or homozygous (AA) rs779805 VHL c.-195G>A polymorphism accompanied by erythrocytosis. These patients are Jak-2 negative, with normal or elevated EPO levels, sometimes with family accumulations and often phlebotomy needs, and in some cases with malignancies in the family. No other cause of erythrocytosis was found. We use phlebotomy regularly, and for those with cardiovascular risk factors, we recommend aspirin.

Genotype-phenotype correlation in von Hippel-Lindau disease

BACKGROUND/AIMS

Retinal haemangioblastomas (RH) remain a major cause of visual impairment in patients with von Hippel-Lindau (VHL) disease. Identification of genotype-phenotype correlation is an important prerequisite for better management, treatment and prognosis.

METHODS

Retrospective, single-centre cohort study of 200 VHL patients. Genetic data and date of onset of RH, central nervous system haemangioblastomas (CNSH), pheochromocytoma/paraganglioma (PPGL), clear cell renal cell carcinoma (ccRCC) and pancreatic neuroendocrine neoplasm (PNEN) were collected. The number and locations of RH were recorded.

RESULTS

The first clinical finding occurred at an age of 26 ± 14 years (y) [mean ± SD]. In 91 ± 3% (95% CI 88-94) of the patients, at least one RH occur until the age of 60y. A total of 42 different rare VHL gene variants in 166 patients were detected. A higher age-related incidence of RH, CNSH, ccRCC and PNEN was detected in patients with a truncating variant (TV) compared to patients with a single amino-acid substitution/deletion (AASD) (all p < 0.01), while it is reverse for PPGL (p < 0.01). Patients with a TV showed 0.10 ± 0.15 RH per y during their lifetime compared to 0.05 ± 0.07 in patients with AASD (p < 0.02). The median enucleation/phthisis-free survival time in patients with a TV was 56y (95% CI 50-62) compared to 78y (95% CI 75-81) in patients with AASD (p < 0.02).

CONCLUSION

Compared to patients with AASD, patients with a TV develop RH, CNSH, ccRCC and PNEN earlier. They experience a higher number of RH and bear a higher risk of enucleation/phthisis. Thus, patients with a TV might be considered for a more intensive ophthalmological monitoring.

The importance of genetic study and long-term management in patients with bilateral pheochromocytomas

Tumors secreting catecholamines, such as pheochromocytomas and paragangliomas, are rare and life-threatening, due to their complications. They can be sporadic or occur in genetic syndromes, such as von Hippel-Lindau in which pheochromocytomas are observed in 10 to 20%. We report a case of a 42 years old male, who was sent in 2016 to our department for neurological symptoms related to cerebellar and central vestibular syndromes. His medical history revealed that at 8 years old he was operated for a symptomatic bilateral pheochromocytoma discovered by adrenergic symptoms and high blood pressure. Cerebral MRI showed intra- and extra-axial, supra- and infratentorial lesions causing supratentorial hydrocephalus associated with leptomeningeal dissemination deemed to be hemangioblastomas. One year later the patient started complaining of chronic diarrhea. The abdominal CT revealed three pancreatic tumors with radiological signs of pancreatic neuroendocrine tumors (PNETs) and a 12 mm mesenteric nodule presenting as a homogenously and typical for NET. The largest PNET had intensive fixation on octreotide scintigraphy. The association of pheochromocytomas, hemangioblastoma and pancreatic neuroendocrine tumors highlighted the diagnosis of VHL syndrome. The family history proved positive in a sibling with bilateral pheochromocytoma in infancy, retinal hemangioblastomas and cerebral hemangioblastoma. Genetic testing would have been useful, but in our case, it was lacking due to poor socio-economic conditions of the patient and absence of genetic testing in public hospitals.

Management recommendations for pancreatic manifestations of von Hippel-Lindau disease

Von Hippel-Lindau disease (VHL) is a multineoplasm inherited disease manifesting with hemangioblastoma of the central nervous system and retina, adrenal pheochromocytoma, renal cell carcinoma, pancreatic neuroendocrine tumors and cysts, and neoplasms/cysts of the ear, broad ligament, and testicles. During 2018-2020, the VHL Alliance gathered several committees of experts in the various clinical manifestations of VHL to review the literature, gather the available evidence on VHL, and develop recommendations for patient management. The current report details the results of the discussion of a group of experts in the pancreatic manifestations of VHL along with their proposed recommendations for the clinical surveillance and management of patients with VHL. The recommendations subcommittee performed a comprehensive systematic review of the literature and conducted panel discussions to reach the current recommendations. The level of evidence was defined according to the Shekelle variation of the Grading of Recommendations, Assessment, Development, and Evaluation grading system. The National Comprehensive Cancer Network Categories of Evidence and Consensus defined the committee members' interpretation of the evidence and degree of consensus. The recommendations encompass the main aspects of VHL-related pancreatic manifestations and their clinical management. They are presented in a clinical orientation, including general planning of screening and surveillance for pancreatic neuroendocrine tumors, utility of biochemical biomarkers, the optimal choice for imaging modality, indirect risk stratification, indications for tissue sampling of VHL-related pancreatic neuroendocrine tumors, and interventions. These recommendations are designed to serve as the reference for all aspects of the screening, surveillance, and management of VHL-related pancreatic manifestations.

Intradural Pediatric Spinal Tumors: An Overview from Imaging to Novel Molecular Findings

Pediatric spinal tumors are rare and account for 10% of all central nervous system tumors in children. Onset usually occurs with chronic nonspecific symptoms and may depend on the intra- or extradural neoplastic location. Meningiomas, schwannomas, and neurofibromas are the most common intradural-extramedullary lesions, while astrocytomas and ependymomas represent the majority of intramedullary tumors. The new molecular discoveries regarding pediatric spinal cancer currently contribute to the diagnostic and therapeutic processes. Moreover, some familial genetic syndromes can be associated with the development of spinal tumors. Currently, magnetic resonance imaging (MRI) is the standard reference for the evaluation of pediatric spinal tumors. Our aim in this review was to describe the imaging of the most frequent intradural intra/extramedullary pediatric spinal tumors and to investigate the latest molecular findings and genetic syndromes.

Papillary Mucinous Adenocarcinoma of the Endolymphatic Sac: A Rare Middle Ear Neoplasm

Glandular neoplasms of the temporal-mastoid region and endolymphatic sac (ELS) are rare, and it is quite challenging to differentiate between an adenoma and an adenocarcinoma. ELS tumors (ELST) usually present with papillary, follicular, or solid patterns and can be further distinguished histologically and through immunohistochemistry. The microscopic features and clinical course of this neoplasm have been comprehensively explained by Heffner, who considered it "low-grade adenocarcinoma of likely ELS origin." The papillary form more commonly affects females, and it is a more aggressive form of ELST that is destructive and exhibits extensive local spread. The tumor usually has a close association with von Hippel-Lindau (VHL) disease, but 11%-30% of the ELST cases develop in individuals without a VHL mutation. ELSTs manifest with headaches, hearing loss, ear discharge, and cranial nerve palsies. Currently, the only available curative therapeutic intervention consists of wide local excision and long-term follow-up. Because of the sensitive location of this tumor, the adjuvant radiotherapy options are still questionable. In this case report, the author presents a 74-year-old woman with a past medical history of Schneiderian papilloma and was diagnosed with papillary mucinous adenocarcinoma of the ELS not associated with VHL disease.

MK-6482 as a potential treatment for von Hippel-Lindau disease-associated clear cell renal cell carcinoma

INTRODUCTION

Von Hippel-Lindau (VHL) disease is an inherited autosomal dominant syndrome caused by a germline mutation and/or deletion of the VHL gene. Inappropriate hypoxia-inducible factor (HIF)-mediated transcription of proangiogenic and metabolic genes leads to the development of tumors and cysts in multiple organs. Surgery is a standard treatment for localized tumors with a risk of metastasis or organ dysfunction. Repeated surgeries cause substantial morbidity and have a major impact on quality of life. There is an urgent need to develop effective and safe systemic treatments for VHL disease manifestations. The small-molecule HIF 2 alpha inhibitor MK-6482 (belzutifan) has demonstrated significant efficacy in VHL disease related renal cell carcinomas, hemangioblastomas, and pancreatic neuroendocrine tumors while demonstrating an acceptable safety profile.

AREAS COVERED

This paper reviews the development of the HIF-2 alpha inhibitor, MK-6482, and discusses preliminary results of ongoing phase I/II studies in renal cell carcinoma (RCC) and VHL disease. An examination of ongoing clinical development of MK-6482 and perspectives on potential future developments and challenges are offered.

EXPERT OPINION

Because of its favorable safety profile, its clear efficacy in VHL disease, promising findings in sporadic, advanced RCC, and convenient oral formulation, MK-6482 is expected to become a leading treatment for VHL disease. Among other currently available oral agents, we believe that MK-6482 will be a preferred treatment for VHL-associated RCC.

Algorithmic assessment of missense mutation severity in the Von-Hippel Lindau protein

Von Hippel-Lindau disease (VHL) is an autosomal dominant rare disease that causes the formation of angiogenic tumors. When functional, pVHL acts as an E3 ubiquitin ligase that negatively regulates hypoxia inducible factor (HIF). Genetic mutations that perturb the structure of pVHL result in dysregulation of HIF, causing a wide array of tumor pathologies including retinal angioma, pheochromocytoma, central nervous system hemangioblastoma, and clear cell renal carcinoma. These VHL-related cancers occur throughout the lifetime of the patient, requiring frequent intervention procedures, such as surgery, to remove the tumors. Although VHL is classified as a rare disease (1 in 39,000 to 1 in 91,000 affected) there is a large heterogeneity in genetic mutations listed for observed pathologies. Understanding how these specific mutations correlate with the myriad of observed pathologies for VHL could provide clinicians insight into the potential severity and onset of disease. Using a select set of 285 ClinVar mutations in VHL, we developed a multiparametric scoring algorithm to evaluate the overall clinical severity of missense mutations in pVHL. The mutations were assessed according to eight weighted parameters as a comprehensive evaluation of protein misfolding and malfunction. Higher mutation scores were strongly associated with pathogenicity. Our approach establishes a novel in silico method by which VHL-specific mutations can be assessed for their severity and effect on the biophysical functions of the VHL protein.

Biological and clinical impact of central nervous system hemangioblastomas in Chinese patients with von Hippel-Lindau disease: implications for treatment

Objective

Central nervous system (CNS) hemangioblastomas (HGBs) are the most frequent cause of mortality in patients with von Hippel-Lindau (VHL) genetic syndrome. However, there is a lack of large studies on the clinical features and optimal management of HGBs in Chinese patients.

Methods

VHL-related HGB cases treated surgically at our hospital from 2012 to 2019 were evaluated. Patients and family members meeting the clinical diagnostic criteria underwent genetic testing. Clinical, genetic and relevant imaging data were analyzed.

Results

Eighty-five VHL patients from 34 pedigrees in 16 Chinese provinces who underwent 121 operations for CNS HGBs were enrolled. Multiple operations were associated with a younger age at first operation (OR = 0.926, 95% CI = 0.871–0.985, P = 0.014, threshold: 27.5, sensitivity: 72.2%, specificity: 71.2%) and a longer postoperative period (OR = 1.096, 95% CI = 1.015–1.184, P = 0.019, threshold: 10.5, sensitivity: 66.7%, specificity: 76.3%). The age at first operation was younger in children than in their parents (23 pairs, P < 0.001). The age at first operation was younger in siblings born later than in those born earlier (10 pairs, P = 0.01). Most untreated tumors (98.2%) remained relatively stable during follow-up (range, 0.5–7; median, 2). However, new tumors continued to emerge (0.14 tumor/year).

Conclusion

VHL-associated CNS HGB is a long-term chronic disease with repeated attacks, likely with genetic anticipation in Chinese pedigrees. When the age at first operation is under 27.5 years, or the postoperative period is longer than 10.5 years, the risk of multiple operations is increased. While most unresected HGBs remain stable after surgery, new tumors may still slowly emerge; hence, scheduled follow-ups are necessary.

Intronic mutation of the VHL gene associated with central nervous system hemangioblastomas in two Chinese families with Von Hippel-Lindau disease: case report

Background

Central nervous system (CNS) hemangioblastomas are the most frequent cause of mortality in patients with Von Hippel–Lindau (VHL) disease, an autosomal dominant genetic disease resulting from germline mutations in the VHL tumor suppressor gene, with most mutations occurring in the exons. To date, there have been no reports of CNS hemangioblastoma cases related to pathogenic variants in intron 2 of VHL, which encodes a tumor suppressor protein (i.e., pVHL) that regulates hypoxia-inducible factor proteins.

Case presentation

We report the presence of a base substitution of c.464-1G > C and c.464-2A > G in the intron 2 of VHL causing CNS hemangioblastomas in six patients with VHL from two Chinese families. The clinical information about the two pathogentic variants has been submitted to ClinVar database. The ClinVar accession for NM_000551.3(VHL):c.464-1G > C was SCV001371687. This finding may provide a new approach for diagnosing and researching VHL-associated hemangioblastomas.

Conclusions

This is the first report of a pathogenic variant at intron 2 in VHL-associated hemangioblastomas. Gene sequencing showed that not only exonic but also intronic mutations can lead to the development of CNS hemangioblastomas.

VHL-Related Neuroendocrine Neoplasms And Beyond: An Israeli Specialized Center Real-Life Report

OBJECTIVE

Von Hippel-Lindau (VHL) syndrome is a rare and complex disease. In 1996, we described a 3 generation VHL 2A kindred with 11 mutation carriers. We aim to share our experience regarding the long-term follow-up of this family and the management of all our other VHL patients focusing on frequently encountered neuroendocrine neoplasms: pheochromocytoma/paraganglioma and pancreatic neuroendocrine neoplasms (PNEN).

METHODS

All VHL patients in follow-up at our tertiary center from 1980 to 2019 were identified. Clinical, laboratory, imaging, and therapeutic characteristics were retrospectively analyzed.

RESULTS

We identified 32 VHL patients in 16 different families, 7/16 were classified as VHL 2 subtype. In the previously described family, the 4 initially asymptomatic carriers developed a neuroendocrine tumor; 7 new children were born, 3 of them being mutation carriers; 2 patients died, 1 due to metastatic PNEN-related liver failure. Pheochromocytoma was frequent (22/32), bilateral (13/22;59%), often diagnosed in early childhood when active screening was timely performed, associated with paraganglioma in 5/22, rarely malignant (1/22), and recurred after surgery in some cases after more than 20 years. PNEN occurred in 8/32 patients (25%), and was metastatic in 3 patients. Surgery and palliative therapy allowed relatively satisfactory outcomes. Severe disabling morbidities due to central-nervous system and ophthalmologic hemangiomas, and other rare tumors as chondrosarcoma in 2 patients and polycythemia in 1 patient were observed.

CONCLUSION

A multidisciplinary approach and long-term follow-up is mandatory in VHL patients to manage the multiple debilitating morbidities and delay mortality in these complex patients.

Clinical decision making in small non-functioning VHL-related incidentalomas

The optimal treatment strategy for patients with small non-functioning VHL-related incidentalomas is unclear. We searched the Freiburg VHL registry for patients with radiologic evidence of pheochromocytoma/paraganglioma (PHEO/PGL). In total, 176 patients with single, multiple, and recurrent tumours were identified (1.84 tumours/patient, range 1-8). Mean age at diagnosis was 32 ± 16 years. Seventy-four percent of tumours were localised to the adrenals. Mean tumour diameter was 2.42 ± 2.27 cm, 46% were <1.5 cm. 24% of tumours were biochemically inactive. Inactive tumours were significantly smaller than active PHEO/PGL at diagnosis (4.16 ± 2.80 cm vs 1.43 ± 0.45 cm; P < 0.025) and before surgery (4.89 ± 3.47 cm vs 1.36 ± 0.43 cm; P < 0.02). Disease was stable in 67% of 21 patients with evaluable tumours ≤1.5 cm according to RECIST and progressed in 7. Time till surgery in these patients was 29.5 ± 20.0 months. A total of 155 patients underwent surgery. PHEO/PGL was histologically excluded in 4 and proven in 151. Of these, one had additional metastatic disease, one harboured another tumour of a different type, and in 2 a second surgery for suspected disease recurrence did not confirm PHEO/PGL. Logistic regression analysis revealed 50% probability for a positive/negative biochemical test result at 1.8 cm tumour diameter. Values of a novel symptom score were positively correlated with tumour size (Rs = 0.46, P < 0.0001) and together with a positive biochemistry a linear size predictor (P < 0.01). Results support standardised clinical assessment and measurement of tumour size and metanephrines in VHL patients with non-functioning incidentalomas <1.5 cm at one year following diagnosis and at individualised intervals thereafter depending on evolving growth dynamics, secretory activity and symptomatology.

Comparison of Current Optical Coherence Tomography Angiography Methods in Imaging Retinal Hemangioblastomas

Purpose

To compare spectral-domain (SD) and swept-source (SS) optical coherence tomography angiography (OCTA) for imaging retinal capillary hemangioblastomas (RCHs) in von Hippel-Lindau disease (VHLD).

Methods

Prospective single-center cross-sectional study. Tumor size (TS) of perfused RCHs was assessed clinically in relation to the optic disc size. For both technologies, SD-OCTA and SS-OCTA, corresponding images with a scan size of 3 × 3 mm² and 6 × 6 mm², respectively, were overlaid according to the set of marker positions to determine the TS.

Results

From 200 patients with VHLD, 48 patients showed 84 RCHs. SD-OCTA images of 39 RCHs (46.4%) and SS-OCTA images of 48 RCHs (57.2%) were suitable for analysis. The average in OCTA-measured TS of 1.60 ± 2.58 mm² (range, 0.01–10.43) was congruent to the clinically assessed TS in 81.3% of cases (r = 0.86, P < 0.0001). TS measured in SD-OCTA compared to SS-OCTA showed similar values and a high correlation (all P < 0.0001). Nevertheless, despite the similarities, a slight trend in SS-OCTA was observed whereby with increasing TS, an elevated TS was detected compared to SD-OCTA (3 × 3-mm² scans: mean difference of 0.03 ± 0.04  mm², 6 × 6-mm² scans: 0.08 ± 0.19 mm²). However, within the same imaging technology method, TS values almost did not differ (SD-OCTA: mean difference of 0.01 ± 0.02 mm², SS-OCTA: 0.001 ± 0.01 mm²).

Conclusions

OCTA may serve as an additional tool for diagnosis and monitoring of RCHs. Nevertheless, due to the differences between the technologies, the values cannot be used interchangeably.

Translational Relevance

SD-OCTA and SS-OCTA are suitable to detect and monitor RCHs and provide a more detailed assessment about the TS than this is clinically possible.

The Efficacy and Safety of Tyrosine Kinase Inhibitors for Von Hippel-Lindau Disease: A Retrospective Study of 32 Patients

Background: Von Hippel-Lindau (VHL) disease is an autosomal-dominant hereditary cancer syndrome. Currently, studies on tyrosine kinase inhibitor (TKI) therapy for VHL disease are scarce. In this study, we retrospectively evaluated the efficacy and safety of four TKIs in patients with VHL disease. Methods: Patients diagnosed with VHL disease who were receiving TKIs were recruited. Patients were treated with sunitinib (n = 12), sorafenib (n = 11), axitinib (n = 6), or pazopanib (n = 3). The therapeutic response was evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Results: From July 2009 to September 2018, 32 patients with VHL disease were eligible and included in this study. The median duration of TKI therapy was 22 months (IQR 8.5-44.75), and the median follow-up period was 31.5 months (IQR 13.5-63.5). According to the RECIST, 9 (28%) of 32 patients showed a partial response, 15 (47%) achieved stable disease, and eight exhibited continued disease progression. A partial response was observed in 11 (31%) of 36 renal cell carcinomas, 4 (27%) of 15 pancreatic lesions, and 1 (20%) of five central nervous system (CNS) hemangioblastomas. The average tumor size decreased significantly for renal cell carcinomas (P = 0.0001), renal cysts (P = 0.027), and pancreatic lesions (P = 0.003) after TKI therapy. Common side effects included hand-foot skin reactions, diarrhea, alopecia, thrombocytopenia, and fatigue. Conclusions: Partial alleviation of VHL disease-related tumors can be achieved by TKI therapies in some patients, providing an alternative treatment strategy, and the side effects of TKIs are acceptable. Larger prospective studies are warranted to further evaluate the efficacy and safety of TKIs in patients with VHL disease.

Growth characteristics and therapeutic decision markers in von Hippel-Lindau disease patients with renal cell carcinoma

Background

Von Hippel-Lindau (VHL) disease is a multi-systemic hereditary disease associated with several benign and malignant tumor entities, including clear cell renal cell carcinoma (ccRCC). Since ccRCCs grow slowly, nephron sparing surgery is typically performed at a tumor diameter of 3–4 cm before the tumor metastasizes. However, in the case of recurrent disease, repeated surgical intervention can impair renal function. Therefore, it is crucial to optimize the timing for surgical interventions through a better understanding of the growth kinetics of ccRCCs in VHL. We investigated tumor growth kinetics and modern volumetric assessment to guide future therapeutic decisions.

Results

The prevalence of ccRCC was 28% in a cohort of 510 VHL patients. Of 144 patients with ccRCC, 41 were followed with serial imaging which identified 102 renal tumors, which exhibited heterogeneous growth kinetics. ccRCCs grew at an average absolute growth rate of 0.287 cm/year, an average relative growth rate [(lnV₁-lnV₀)/(t₁-t₀)] of 0.42% and an average volume doubling time of 27.15 months. Women had a faster relative growth rate than men. Age and specific mutations did not influence tumor growth. Because of the tumor heterogeneity, we developed an additional cut-off volume of 40 cm³ for surgical intervention.

Conclusions

Tumor heterogeneity and differences in growth kinetics is suggestive of a state of transient tumor dormancy in ccRCCs of VHL patients. The relative growth rate has not been previously described in other studies. Volumetric assessment as an additional parameter for surgical intervention could be a useful clinical tool and needs further investigation.

Distinctive clinicopathological features of Von Hippel-Lindau-associated hereditary renal cell carcinoma: A single-institution study

Von Hippel-Lindau (VHL) disease is a genetic syndrome that involves the development of tumors in numerous organs. The kidney is one of the most frequently affected organs, and patients with VHL and renal tumors require repeated nephrectomy. The present study aimed to further determine the clinicopathological characteristics of patients with VHL-associated renal cell carcinoma (RCC), which may allow more rational clinical treatment decisions. This study included 27 patients with VHL who underwent radical or partial nephrectomy at the Peking University First Hospital between January 2010 and April 2018. The clinicopathological characteristics and prognosis of the patients were retrospectively reviewed. The expression of RCC-associated molecular markers was evaluated by immunohistochemistry. The mean size of the renal tumors was 4.3±2.0 cm (range 1.3–9.5 cm). The pathological type in 26 cases (96.3%) was clear cell RCC (CCRCC), whereas only one patient was diagnosed with CCRCC and clear cell papillary RCC. Renal cysts with a clear cell lining were observed, and RCC cell clusters were scattered in renal cyst cavities. Among the 27 patients, 21 (77.8%) were diagnosed with stage IA/T1N0M0, according to Tumor-Node-Metastasis staging, and 16 (59.3%) had grade 1 tumors. The mean postoperative follow-up duration was 39.0±24.0 months (range, 1.7–96.5 months). No metastasis or VHL-associated mortality was observed. VHL-associated RCC is a relatively low-risk disease, and a tumor size of 4 cm was determined as a threshold for nephron-sparing surgery. In addition, to prevent tumor cell dispersion, renal cysts should be carefully treated. A comprehensive understanding of the clinicopathological characteristics and underlying mechanisms of RCC associated with VHL syndrome may improve patient prognosis.

Overview of Monogenic or Mendelian Forms of Hypertension

Monogenic or Mendelian forms of hypertension are described as a group of conditions characterized by insults to the normal regulation of blood pressure by the kidney and adrenal gland. These alterations stem from single mutations that lead to maladaptive overabsorption of electrolytes with fluid shift into the vasculature, and consequent hypertension. Knowledge of these various conditions is essential in diagnosing pediatric or early-onset adult hypertension as they directly affect treatment strategies. Precise diagnosis with specific treatment regimens aimed at the underlying physiologic derangement can restore normotension and prevent the severe sequelae of chronic hypertension.

Differential Expression of PD-L1 Between Sporadic and VHL-Associated Hereditary Clear-Cell Renal Cell Carcinoma and Its Correlation With Clinicopathological Features

BACKGROUND

Programmed death ligand-1 (PD-L1) is a potential predictive biomarker for immunotherapy in several malignancies. However, the expression level and clinical significance of PD-L1 in von Hippel-Lindau (VHL)-associated hereditary clear-cell renal cell carcinoma (ccRCC) remain unclear.

PATIENTS AND METHODS

Surgical specimens were recruited from 129 patients with sporadic ccRCC and 26 patients with VHL-associated hereditary ccRCC. The PD-L1 expression level was assessed using immunohistochemistry. Correlations between PD-L1 expression and clinicopathological features were analyzed.

RESULTS

In sporadic ccRCC, the positive expression rate of PD-L1 was 47.3% (61/129). Positive PD-L1 expression was correlated with advanced tumor T stage (P = .011), higher Fuhrman nuclear grade (P = .022), poor disease-free survival (P = .037), and sex (P = .025). In the VHL-associated hereditary ccRCC, positive PD-L1 expression rate was 34.6% (9/26), lower than that in sporadic ccRCC. Positive PD-L1 was correlated with higher Fuhrman nuclear grade (P = .008), but not with sex, age, tumor stage, or the onset age of VHL-associated tumors.

CONCLUSION

Positive PD-L1 expression was correlated with the aggressive clinicopathological features in sporadic and VHL-associated hereditary ccRCC. Whether PD-L1 expression level in ccRCC is related to the effectiveness of programmed death-1/PD-L1 checkpoint inhibitor immunotherapy needs to be further investigated.

Germline VHL gene variant in patients with von Hippel-Lindau disease does not predict renal tumor growth

PURPOSE

To determine whether the type of VHL gene pathogenic variant influences the growth rate or CT enhancement values of renal lesions in VHL patients.

MATERIALS AND METHODS

Thirty-two VHL patients (19 male) were selected from a prospectively maintained imaging database for patients that underwent surgical tumor resection between 2014 and 2016. One hundred and eleven VHL lesions were marked for resection and pathology analysis. Whole lesion volumetric segmentation was performed on nephrographic phase of the two most recent contrast-enhanced CT scans before surgery. Intensity distribution curves were obtained from segmentations. A linear mixed model, accounting for within-patient correlations, was used to compare the growth and enhancement differences between different germline pathogenic variant types.

RESULTS

There was no significant difference for the lesions' total growth between different germline pathogenic variants (P value = 0.78). The median growth rate for all lesions was 1.7 cc/year (IQR 0.5, 3.9) with a baseline median size of 4.1 cm³ (IQR 1.7, 11.7). In complex lesions, the solid portion of the tumor demonstrated a higher growth rate (1.6 cc/year) than cystic portions (0.02 cc/year) which stayed relatively unchanged. Only one pathogenic variant (Splice donor) showed some levels of difference in its relative enhancement from other subtypes.

CONCLUSION

The type of germline pathogenic variant on the VHL gene does not affect the growth rate or CT enhancement values of renal lesions in patients with VHL. The absolute growth rate of these tumors may be used in the scheduling of follow-up studies.

Preventive medicine of von Hippel-Lindau disease-associated pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PanNETs) are rare in von Hippel-Lindau disease (VHL) but cause serious morbidity and mortality. Management guidelines for VHL-PanNETs continue to be based on limited evidence, and survival data to guide surgical management are lacking. We established the European-American-Asian-VHL-PanNET-Registry to assess data for risks for metastases, survival and long-term outcomes to provide best management recommendations. Of 2330 VHL patients, 273 had a total of 484 PanNETs. Median age at diagnosis of PanNET was 35 years (range 10-75). Fifty-five (20%) patients had metastatic PanNETs. Metastatic PanNETs were significantly larger (median size 5 vs 2 cm; P < 0.001) and tumor volume doubling time (TVDT) was faster (22 vs 126 months; P = 0.001). All metastatic tumors were ≥2.8 cm. Codons 161 and 167 were hotspots for VHL germline mutations with enhanced risk for metastatic PanNETs. Multivariate prediction modeling disclosed maximum tumor diameter and TVDT as significant predictors for metastatic disease (positive and negative predictive values of 51% and 100% for diameter cut-off ≥2.8 cm, 44% and 91% for TVDT cut-off of ≤24 months). In 117 of 273 patients, PanNETs >1.5 cm in diameter were operated. Ten-year survival was significantly longer in operated vs non-operated patients, in particular for PanNETs <2.8 cm vs ≥2.8 cm (94% vs 85% by 10 years; P = 0.020; 80% vs 50% at 10 years; P = 0.030). This study demonstrates that patients with PanNET approaching the cut-off diameter of 2.8 cm should be operated. Mutations in exon 3, especially of codons 161/167 are at enhanced risk for metastatic PanNETs. Survival is significantly longer in operated non-metastatic VHL-PanNETs.

Identification of a VHL gene mutation in a Chinese family with Von Hippel‑Lindau syndrome

Von Hippel‑Lindau (VHL) syndrome is an autosomal dominant neoplastic disorder. The VHL tumor suppressor (VHL) gene has previously been identified to represent the causative gene of VHL. Previous studies have demonstrated that >506 different mutations in VHL are associated with VHL syndrome. The aim of the present study was to determine the VHL gene mutation present in a VHL syndrome pedigree and to investigate the pathogenesis of the mutant protein. Briefly, a family suffering from VHL syndrome in a Chinese Han population was recruited, and a missense mutation (c.345 C>A: p.H115Q) was revealed to be present within the VHL gene in the proband. Furthermore, Sanger sequencing revealed two carriers of the mutation within the family. The results of the present study also demonstrated a mutation in VHL associated with the VHL syndrome phenotype, which may be of future therapeutic benefit for the diagnosis of VHL syndrome. These results may also be relevant to further studies aiming to investigate the molecular pathogenesis of VHL syndrome.

Pedigree analysis, diagnosis and treatment in Von Hippel-Lindau syndrome: A report of three cases

The objective of the present study was to systematically investigate the clinical features, diagnosis and therapeutic treatment of Von Hippel-Lindau (VHL) syndrome in order to improve understanding of this disease. A total of 3 cases of VHL syndrome treated at the Affiliated Hospital of Zunyi Medical College (Zunyi, China) between September 2014 and October 2015 were retrospectively analyzed. The associated literature was reviewed, and the diagnostic and therapeutic features were discussed. Case 1 was diagnosed as VHL syndrome accompanied by a renal tumor on the right side, and radical tumor resection in the right kidney was performed. Postoperative pathological examination indicated clear cell carcinoma. Case 2 was diagnosed as VHL syndrome accompanied by bilateral adrenal pheochromocytoma. The left-side adrenal tumor was removed, and postoperative pathological analysis was suggestive of adrenal pheochromocytoma. Case 3 visited the hospital due to the presence of masses on the left and right sides of the kidney, but did not undergo surgery for personal reasons. Follow-ups were scheduled subsequent to surgery at another hospital. The diagnosis in all 3 cases was confirmed by genetic testing, where VHL mutations were detected in all patients. Following surgery, pedigree and genetic analysis was performed in all 3 pedigrees and VHL mutations were identified in 7 family members. The diagnosis of VHL syndrome should be based on the clinical manifestation of the patients and the results of genetic tests. DNA analysis of mutations is the main method for diagnosis. An appropriate surgical plan should be formulated based on the site, size and number of tumors, and the condition of the patient. Since VHL syndrome is an inheritable genetic disorder and relapse following surgery is common, pedigree analysis of the patient and lifelong follow-ups are essential. Additionally, physicians should pay attention to VHL syndrome in order to avoid missing diagnosis or misdiagnosis.

Surgical approach for suprasellar hemangioblastomas preserving the pituitary stalk: Review of the literature and report of a further case

Hemangioblastomas (HBLs) are challenging vascular tumours with rare suprasellar location Surgery is recommended in patients with visual impairment, endocrine disorders or hydrocephalus. Surgical removal of pituitary stalk HBLs is challenging due to their location and high vascularity. Our narrative review was guided by the question: "what is the more suitable surgical approach to excise a suprasellar HBL?". Pertinent English literature was scrutinized from database inception to October 2016. Eighteen articles matched our selection criteria. Among the surgically treated patients, 4 were treated through a trans-sphenoidal (TS) approach, 13 through a transcranial approach (2 of them after TS failure). Five other cases were treated with radiotherapy (adjuvant in 3 cases) and 9 patients were managed with simple observation and/or medical treatment. We add a case of complete suprasellar HBL resection through an orbito-zygomatic (OZ) craniotomy with extradural anterior clinoidectomy (EAC). To achieve satisfactory oncologic results with acceptable morbidity for symptomatic suprasellar HBLs, complete tumour removal with pituitary stalk sparing should be attempted through an OZ craniotomy with EAC that provides adequate exposure of the tumour, its vascular supply and the adjacent neural structures.

Renal Cell Carcinoma in von Hippel-Lindau Disease-From Tumor Genetics to Novel Therapeutic Strategies

von Hippel-Lindau (VHL) disease is an autosomal dominant syndrome caused by mutations in the VHL tumor-suppressor gene, leading to the dysregulation of many hypoxia-induced genes. Affected individuals are at increased risk of developing recurrent and bilateral kidney cysts and dysplastic lesions which may progress to clear cell renal cell carcinoma (ccRCC). Following the eponymous VHL gene inactivation, ccRCCs evolve through additional genetic alterations, resulting in both intratumor and intertumor heterogeneity. Genomic studies have identified frequent mutations in genes involved in epigenetic regulation and phosphoinositide 3-kinase-AKT-mechanistic target of rapamycin (mTOR) pathway activation. Currently, local therapeutic options include nephron-sparing surgery and alternative ablative procedures. For advanced metastatic disease, systemic treatment, including inhibition of vascular endothelial growth factor pathways and mTOR pathways, as well as immunotherapy are available. Multimodal therapy, targeting multiple signaling pathways and/or enhancing the immune response, is currently being investigated. A deeper understanding of the fundamental biology of ccRCC development and progression, as well as the development of novel and targeted therapies will be accelerated by new preclinical models, which will greatly inform the search for clinical biomarkers for diagnosis, prognosis, and response to treatment.

Retinal hemangioblastoma: prevalence, incidence and frequency of underlying von Hippel-Lindau disease

Background and aims

We aimed to determine the frequency of von Hippel-Lindau disease (vHL) as the underlying cause of retinal hemangioblastoma and to estimate retinal hemangioblastoma incidence and prevalence in a national cohort study.

Methods

Through the national patient register and vHL research database, we identified 81 patients diagnosed with a retinal hemangioblastoma in Denmark between 1977 and 2014. Consent was obtained for 54 living and 10 deceased patients with retinal hemangioblastoma. For each participant, we collected medical records and family information. Almost all (63 of 64) participants were or had previously been tested for mutations in the VHL gene.

Results

Overall, 84% of the participants (54 of the 64) had vHL. Compared with the non-vHL patients, the vHL patients had their first retinal hemangioblastoma at a younger age (22.5 vs 40 years), and were more likely to have an asymptomatic first hemangioblastoma (80% vs 20%). Overall, 76% (41 of 54) of the vHL patients had a family history of vHL, while none of the patients without vHL did. Despite the rarity of the disease, on average more than eight new tumours are diagnosed each year due to multiple tumour development in vHL patients. The estimated prevalence of patients with retinal hemangioblastoma was up to 1 in 73 080 individuals.

Conclusion

In the first national study in which almost all participants were genetically tested, vHL was the underlying cause of retinal hemangioblastoma in 84% of cases; more often than previously reported. We recommend that genetic and clinical vHL screening should be performed in all patients with retinal hemangioblastoma.

Microsurgical Treatment of Sporadic and von Hippel-Lindau Disease Associated Spinal Hemangioblastomas: A Single-Institution Experience

Study Design

Retrospective cohort study.

Purpose

To examine the clinical profile and surgical complications in patients with spinal hemangioblastomas and to evaluate the long-term outcome in them.

Overview of Literature

Although considered to be histologically benign, hemangioblastomas may cause significant neurological deficits. The proportion of spinal hemangioblastomas associated with von Hippel–Lindau (VHL) disease has been estimated be 13%–59%. Preoperative neurological function correlates with postoperative neurological status. Studies have shown no difference in outcomes between sporadic and VHL-associated spinal hemangioblastomas.

Methods

This retrospective study included 14 consecutive patients treated for spinal hemangioblastomas at our institute between January 2000 and June 2013. The mean follow-up period was 5 years. Magnetic resonance imaging of the complete neuraxis was performed in all cases, and preoperative embolization was performed in two cases.

Results

In total, 14 patients underwent 18 surgeries, of which 15 were for spinal hemangioblastomas. Of all the patients, 86% had motor weakness and 79% presented with sensory disturbances. Preoperative McCormick functional grades were grade I in 7 (50%), grade II in 3 (21%), and grade III in 4 (29%) patients; 50% patients were diagnosed with VHL disease. All patients underwent complete resection of the tumor. Eight patients experienced deterioration in their neurological status in the immediate postoperative period; among them, five had gradual improvement. At 5-year follow-up, 11 (78.57%) patients showed good functional outcomes.

Conclusions

Microsurgical excision of spinal hemangioblastomas can cause postoperative morbidity, mainly in the form of neurological deterioration. Almost half of our patients had deterioration in the McCormick grade in the immediate postoperative period. However, a complete microsurgical excision can result in good long-term functional outcomes, as most of the immediate postoperative neurological deterioration in our patients was reversible. There was no difference in the long-term functional outcomes between sporadic and VHL-associated spinal hemangioblastomas.

Single-stage laparoscopic adrenalectomy for pheochromocytoma and enucleation of a pancreatic neuroendocrine tumor in Von Hippel-Lindau disease: A case report

Von Hippel-Lindau (VHL) disease is an inherited syndrome with autosomal-dominant transmission, characterized by central nervous system and retinal hemangioblastomas, visceral cysts and tumors. Optimal surgical treatment, including its timing, remains a controversial topic. The present study reports the case of a 67-year-old female patient with adrenal and pancreatic manifestations of VHL. A laparoscopic cortex-sparing left adrenalectomy for a 4-cm pheochromocytoma and pancreatic enucleation for pancreatic polypeptidoma of the pancreas tail were performed during the same operative procedure. The total operative time was 240 min. There were no operative complications, and the surgery was completed laparoscopically with minimal blood loss. A prolonged hospital stay was necessary to treat a grade C postoperative pancreatic fistula. The histopathological result was an adrenal pheochromocytoma and a well-differentiated neuroendocrine tumor, secreting pancreatic polypeptides. In conclusion, organ-sparing laparoscopic surgery is an important option for treating simultaneous lesions in several abdominal solid viscera, such as VHL disease, and the present case study represents, to the best of the authors' knowledge, the first report of single-stage laparoscopic adrenalectomy and pancreatic tumor enucleation.

Prevalence, birth incidence, and penetrance of von Hippel-Lindau disease (vHL) in Denmark

Von Hippel-Lindau disease (vHL) is a rare hereditary tumour predisposition with multiorgan involvement that is not always easily recognized. The disease is reported to be almost fully penetrant at age 60 years. Previous estimates of vHL prevalence and incidence are all regional and vary widely. Most are >20 years old and prone to selection bias because of inclusion of only clinically affected vHL patients who were diagnosed before genetic testing was available. In an unselected cohort of all known Danish carriers of a disease-causing VHL variant, we assessed vHL penetrance on a national basis. We further used national health registers to identify individuals who fulfilled the clinical diagnostic vHL criteria based on their registered diagnostic codes, but had not been diagnosed with vHL. We also assessed the medical histories of first-degree relatives to identify familial cases. This study gives the first national estimates of vHL prevalence (1 in 46 900 individuals) and birth incidence (1 in 27 300 live births). vHL has been underdiagnosed in Denmark, and as many as 25% of the overall vHL cohort (diagnosed+undiagnosed patients) have a missed diagnosis in spite of fulfilling the international diagnostic criteria. We found an overall penetrance of 87% at age 60 years. When considering only vHL patients who have not attended surveillance, 20% will still be asymptomatic at age 60 years. This should be considered in the context of genetic counselling, especially when assessing the risk of vHL in asymptomatic adult first-degree relatives who are often not genetically tested.