Von Hippel-Lindau disease: a genetic study

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.

A Cerebellar Tumor-to-Tumor Metastasis in a Patient With Von Hippel-Lindau Disease

Tumor-to-tumor metastasis in the central nerve system is uncommon in our routine practice. Most reports include metastatic breast cancer into meningioma. Here we report a metastatic clear cell renal cell carcinoma (ccRCC) into a cerebellar hemangioblastoma in a patient with von Hippel-Lindau (VHL) disease. Imaging cannot distinguish metastatic ccRCC from primary cerebellar hemangioblastoma. Immuno-molecular studies are proven to be diagnostic. We also reviewed previously documented tumor-to-tumor metastasis of ccRCC to cerebellar hemangioblastoma in VHL disease. Lastly, we discussed potential mechanisms involved in the metastasis of ccRCC to hemangioblastoma in the cerebellum in patients with VHL.

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.

ZEISS PLEX Elite 9000 Widefield Optical Coherence Tomography Angiography as Screening Method for Early Detection of Retinal Hemangioblastomas in von Hippel-Lindau Disease

Purpose

To evaluate early detection of retinal hemangioblastomas (RHs) in von Hippel-Lindau disease (VHLD) with widefield optical coherence tomography angiography (wOCTA) compared to the standard of care in ophthalmologic VHLD screening in a routine clinical setting.

Methods

We conducted prospective comparisons of three screening methods: wOCTA, standard ophthalmoscopy, and fluorescein angiography (FA), which was performed only in uncertain cases. The numbers of detected RHs were compared among the three screening methods. The underlying causes for the lack of detection were investigated.

Results

In 91 eyes (48 patients), 67 RHs were observed (mean, 0.74 ± 1.59 RH per eye). FA was performed in eight eyes. Ophthalmoscopy overlooked 25 of the 35 RHs detected by wOCTA (71.4%) due to the background color of the choroid (n = 5), small tumor size (n = 13), masking by a bright fundus reflex (n = 2), and masking by surrounding retinal scars (n = 5). However, wOCTA missed 29 RHs due to peripheral location (43.3%). The overall detection rates were up to 37% on the basis of ophthalmoscopy alone, up to 52% for wOCTA, and 89% for FA. Within the retinal area covered by wOCTA, the detection rates were up to 46.7% for ophthalmoscopy alone, up to 92.1% for wOCTA, and 73.3% for FA.

Conclusions

The overall low detection rate of RHs using wOCTA is almost exclusively caused by its inability to visualize the entire peripheral retina. Therefore, in unclear cases, FA is necessary after ophthalmoscopy.

Translational Relevance

Within the imageable retinal area, wOCTA shows a high detection rate of RHs and therefore may be suitable to improve screening for RHs in VHLD.

Von Hippel-Lindau Disease (VHL): Characteristic Lesions with Classic Imaging Findings

Von Hippel-Lindau disease (VHL) is a multisystem cancer syndrome caused by the inactivation of the VHL tumor suppressor gene and involves various organ systems including the central nervous system (CNS), endocrine system, and the kidneys. Tumors seen in patients with VHL disease can be benign or malignant and are usually multifocal, bilateral, and hypervascular in nature. As most lesions associated with VHL are asymptomatic initially, early diagnosis and the institution of an evidence-based surveillance protocol are of paramount importance. Screening, surveillance, and genetic counseling are key aspects in the management of patients diagnosed with VHL disease and often require a multidisciplinary approach and referral to specialized centers. This article will discuss the characteristic lesions seen with VHL disease, their diagnosis, screening protocols and management strategies, as well as an illustrative case to demonstrate the natural progression of the disease with classic imaging findings.

Pediatric Spinal Hemangioblastomas: Clinical Features and Surgical Outcomes of 39 Cases

Objective: Spinal hemangioblastomas (HBs) are a rare pathology, especially in the pediatric population. The natural history and long-term outcomes of pediatric patients with spinal HBs remain unclear due to their scarcity.Methods: A retrospective review of the clinical data and treatment outcomes of children with spinal HBs in our institution from 2012 to 2021 was conducted.Results: Thirty-nine pediatric patients were included, with an average age of 15.9 ± 2.9 years (range, 8–18 years), and 51.3% were female. Children were more likely to have von Hippel-Lindau (VHL) disease (p < 0.001), a family history of VHL (p < 0.001), multiple symptoms (p = 0.006), a shorter duration of symptoms (p < 0.001), and a larger lesion size (p = 0.004) and volume (p = 0.008) than their adult counterparts. The VHL-associated group of patients was more likely to present with multiple symptoms (p = 0.026), have a family history of VHL (p < 0.001), have multiple HBs (p < 0.001) and have synchronous intracranial lesions (p < 0.001) than the sporadic group. After surgery, 15 patients (38.5%) showed improved clinical outcomes, 17 patients (43.6%) remained unchanged, 4 patients (10.2%) worsened, and 3 patients (7.7%) died of tumor progression. During follow-up, there was a high rate of recurrence and repeated surgery, especially for children in the VHL-associated group.Conclusion: Pediatric patients with spinal HBs appear to have a higher relapse risk than their adult counterparts. Therefore, life-long follow-up of these patients is necessary, especially for VHL-associated cases. Surgery can benefit children with HBs and should be considered early to avoid irreversible neurological deterioration.

A complementary comment on primary hepatic angiosarcoma: A case report

BACKGROUND

This article examines primary hepatic angiosarcoma (PHA) and fat-poor angiomyolipoma (AML), two uncommon vascular cancers. Clinical decisions in these situations are frequently aided by pathology reports and imaging techniques. Uncommon malignant tumors of the vascular endothelium include PHA. Another diagnosis that should not be overlooked when employing contrast-enhanced MR and contrast-enhanced computed tomography (CT) imaging techniques is fat-poor AML, one of the uncommon vascular tumors of the liver. In both conditions, biopsy is the primary means of diagnosis.

CASE SUMMARY

In our article, besides the diagnosis of PHA, fat-poor AML, one of the other rare vascular tumors of the liver, is mentioned. In the case, a 50-year-old female patient with VHL Syndrome was admitted to our hospital with nonspecific lesions such as right upper quadrant pain, weight loss, and nausea. Abdominal ultrasonography (US) revealed a hypoechoic heterogeneous lesion with occasional faint contours. In computed tomography, it was observed as a hyperdense nodular lesion in segment 4. Magnetic resonance imaging (MRI) revealed that the lesion did not contain fat. In connection with the known history of VHL Syndrome, we first evaluated the possibility of AML. Thereupon, a histopathological sample was taken and the diagnosis was made as fat-poor AML with 5% fat content.

CONCLUSION

In conclusion, PHA in our case report and fat-poor AML in our clinic are two uncommon liver vascular malignancies with comparable incidences. Important imaging techniques like contrast-enhanced US (CEUS), CECT, and CEMRI give us substantial advantages in both cases. However, a biopsy is used to provide the final diagnosis.

Novel Manifestation of Retinal Hemangioblastomas Detected by OCT Angiography in von Hippel-Lindau Disease

PURPOSE

To elucidate the clinical characteristics of atypical retinal vascular proliferation in patients with von Hippel-Lindau (VHL) disease using OCT angiography (OCTA).

DESIGN

Prospective, observational study.

PARTICIPANTS

Fifty-seven consecutive patients with a diagnosis of VHL disease who visited Kyoto University Hospital between January 2019 and March 2022.

METHODS

Retinal hemangioblastomas (RHs) were assessed using multimodal imaging including OCTA. RHs were classified into 2 phenotypes: nodular and flat. Nodular RHs were defined as typical RHs that were globular, well-circumscribed tumors, often accompanied with dilated feeder arterioles and draining venules. Flat RHs lacked a protruded red or colored mass, had variable and indistinct borders, and were not accompanied with feeder and draining vessels.

MAIN OUTCOME MEASURES

The prevalence, distribution, and description of atypical flat RHs.

RESULTS

Among 57 consecutive patients with VHL disease, 37 patients (64.9%) showed RHs in at least 1 eye. Bilateral RHs were seen in 23 patients (62.2%). Among 58 eyes of 37 patients with RHs, typical nodular RHs were detected in 54 eyes. Nodular RHs were seen mainly in the peripheral retina and occasionally in the peripapillary region, and they showed exudative changes in some cases. Flat RHs were detected in 7 eyes (12.1%). Four eyes showed only flat RHs, and 3 eyes showed both types in the same eye. Most flat RHs appeared as retinal hemorrhages or faint flat abnormal retinal vessels in the inner retina on the fundus examination, often within the macula area or peripapillary. In all eyes with flat RHs, OCTA showed abundant blood flow in the lesions. OCT revealed that flat RHs were seen mainly between the retinal nerve fiber layer and the ganglion cell layer, and occasionally within the inner nuclear layer. During a mean follow-up period of 20.4 ± 15.0 months, no flat RHs accompanied exudative change, tractional retinal detachment, or progression in size.

CONCLUSIONS

Patients with VHL disease can demonstrate 2 distinct types of RHs: the classic nodular type and an atypical flat type. OCT angiography can be useful in improving the detection of atypical flat RHs, which can be difficult to detect clinically.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

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.

Robot-assisted sutureless partial nephrectomy for the treatment of fifteen bilateral renal masses in a patient with Von Hippel-Lindau syndrome: a case report from a high-volume robotic center

Renal cell carcinoma is among major causes of death in patients with Von Hippel-Lindau (VHL) syndrome, and it usually presents with multiple and bilateral lesions that may require multiple renal surgeries. This, in turn, may compromise renal function, resulting in end-stage renal disease. To minimize renal function impairment in these patients, great importance is given to the preservation of functional parenchyma with the use of nephron-sparing techniques. Furthermore, new techniques such as off-clamp surgery, selective suturing or sutureless techniques may improve long-term functional outcomes. We described the case of a 27-year-old male patient with a family history of VHL disease affected by multiple, bilateral renal masses. He received bilateral, metachronous robot-assisted partial nephrectomies (RAPN) for a total of 15 renal lesions. No intra- or post-operative complications occurred, and the patient was discharged on the second postoperative day after both procedures. Serum creatinine after the second RAPN was 0.99 mg/dl (baseline value was 1.11 mg/dl). In patients with VHL syndrome and multiple renal lesions, robot-assisted partial nephrectomy, especially with the use of clampless and sutureless techniques, helps minimizing renal function impairment and should be performed when anatomically and technically feasible.

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.

The Epidemiology of Brain and Spinal Cord Tumors

CNS tumors are a diverse group of neoplasms that emerge from a variety of different CNS cell types. These tumors may be benign, malignant, or borderline in nature. The majority of high grade glial tumors are fatal, with the exception of pilocytic astrocytoma. Primary malignant CNS tumors occur at a global annual rate of 2.1 to 5.8 per 100,000 persons. Males are more likely to develop malignant brain tumors than females, whereas benign meningiomas are more common in adult females. Additionally, gender inequalities in non-malignant tumors peak between the ages of 25 and 29 years. Only a small number of genetic variants have been associated with survival and prognosis. Notably, central nervous system (CNS) tumors exhibit significant age, gender, and race variation. Race is another factor that affects the incidence of brain and spinal cord tumors. Different races exhibit variation in terms of the prevalence of brain and CNS malignancies. This chapter discusses ongoing research on brain and spinal cord tumor epidemiology, as well as the associated risks and accompanied disorders.

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.

VHL Ser65 mutations enhance HIF2α signaling and promote epithelial-mesenchymal transition of renal cancer cells

Background

Von Hippel-Lindau (VHL) disease is an autosomal dominant genetic neoplastic disorder caused by germline mutation or deletion of the VHL gene, characterized by the tendency to develop multisystem benign or malignant tumors. The mechanism of VHL mutants in pathogenicity is poorly understand.

Results

Here we identified heterozygous missense mutations c.193T > C and c.194C > G in VHL in several patients from two Chinese families. These mutations are predicted to cause Serine (c.193T > C) to Proline and Tryptophan (c.194C > G) substitution at residue 65 of VHL protein (p.Ser65Pro and Ser65Trp). Ser65 residue, located within the β-domain and nearby the interaction sites with hypoxia-inducing factor α (HIFα), is highly conserved among different species. We observed gain of functions in VHL mutations, thereby stabilizing HIF2α protein and reprograming HIF2α genome-wide target gene transcriptional programs. Further analysis of independent cohorts of patients with renal carcinoma revealed specific HIF2α gene expression signatures in the context of VHL Ser65Pro or Ser65Trp mutation, showing high correlations with hypoxia and epithelial-mesenchymal transition signaling activities and strong associations with poor prognosis.

Conclusions

Together, our findings highlight the crucial role of pVHL-HIF dysregulation in VHL disease and strengthen the clinical relevance and significance of the missense mutations of Ser65 residue in pVHL in the familial VHL disease.

Supratentorial hemangioblastoma: A rare case report and literature review

Hemangioblastomas are rare and benign tumors of the central nervous system. They account for 1.5%-2.5% of all intracranial tumors and have an incidence of 3.2%. The resemblance of hemangioblastomas to other tumors renders preoperative diagnosis and management challenging. Herein, we report a case of a supratentorial hemangioblastoma accompanied by extensive reactive gliosis and diagnosed through magnetic resonance imaging. In addition, we review the relevant literature.

Stereotactic Body Radiotherapy for Renal Cell Carcinoma in Patients with Von Hippel–Lindau Disease—Results of a Prospective Trial

Simple Summary

Clear cell renal cell carcinoma (ccRCC) frequently occurs in patients with von Hippel–Lindau disease and is a leading cause of mortality in patients with this hereditary disorder. Partial nephrectomy, which is the standard treatment, is often complicated by multilocular tumor occurrence in both kidneys requiring repeated surgeries. Consequently, nephron-sparing resections become increasingly difficult ultimately leading to chronic kidney failure. In these patients or in patients who refuse surgery, alternative treatment approaches are needed. In this study, we investigated the outcome and toxicities especially for the kidney after stereotactic body radiotherapy (SBRT). We could demonstrate that SBRT in this highly vulnerable group of patients is feasible without any high-grade adverse events in the long-term and results in excellent local control at the site of treatment. Efficacy of SBRT is already proven for other anatomic sites and it could represent a valuable, non-invasive treatment option for ccRCC as well, especially for patients who are extremely vulnerable to any kidney injury. Further prospective trials evaluating SBRT for localized ccRCC are necessary to verify the promising findings and to examine its role as an alternative to surgery in inoperable patients.

Abstract

Von Hippel–Lindau disease (VHL) is a hereditary disorder associated with malignant tumors including clear cell renal cell carcinoma (ccRCC). Partial nephrectomy is complicated by multilocular tumor occurrence and a high recurrence rate. The aim of this study was to evaluate the potential of stereotactic body radiotherapy (SBRT) as an alternative treatment approach in VHL patients with multiple ccRCC. Patients with VHL and a diagnosis of ccRCC were enrolled. SBRT was conducted using five fractions of 10 Gy or eight fractions of 7.5 Gy. The primary endpoint was local control (LC). Secondary endpoints included alteration of renal function and adverse events. Seven patients with a total of eight treated lesions were enrolled. Median age was 44 years. Five patients exhibited multiple bilateral kidney cysts in addition to ccRCC. Three patients underwent at least one partial nephrectomy in the past. After a median follow-up of 43 months, 2-year LC was 100%, while 2-year CSS, 2-year PFS and 2-year OS was 100%, 85.7% and 85.7%, respectively. SBRT was very well tolerated with no acute or chronic toxicities grade ≥ 2. Mean estimated glomerular filtration rate (eGFR) at baseline was 83.7 ± 13.0 mL/min/1.73 m², which decreased to 76.6 ± 8.0 mL/min/1.73 m² after 1 year. Although the sample size was small, SBRT resulted in an excellent LC rate and was very well tolerated with preservation of kidney function in patients with multiple renal lesions and cysts.

Hypoxia-inducible factor underlies von Hippel-Lindau disease stigmata

von Hippel-Lindau (VHL) disease is a rare hereditary cancer syndrome that causes a predisposition to renal clear-cell carcinoma, hemangioblastoma, pheochromocytoma, and autosomal-recessive familial polycythemia. pVHL is the substrate conferring subunit of an E3 ubiquitin ligase complex that binds to the three hypoxia-inducible factor alpha subunits (HIF1-3α) for polyubiquitylation under conditions of normoxia, targeting them for immediate degradation by the proteasome. Certain mutations in pVHL have been determined to be causative of VHL disease through the disruption of HIFα degradation. However, it remains a focus of investigation and debate whether the disruption of HIFα degradation alone is sufficient to explain the complex genotype-phenotype relationship of VHL disease or whether the other lesser or yet characterized substrates and functions of pVHL impact the development of the VHL disease stigmata; the elucidation of which would have a significant ramification to the direction of research efforts and future management and care of VHL patients and for those manifesting sporadic counterparts of VHL disease. Here, we examine the current literature including the other emergent pseudohypoxic diseases and propose that the VHL disease-phenotypic spectrum could be explained solely by the varied disruption of HIFα signaling upon the loss or mutation in pVHL.

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.

Neuropathologic features of central nervous system hemangioblastoma

Hemangioblastoma is a benign, highly vascularized neoplasm of the central nervous system (CNS). This tumor is associated with loss of function of the VHL gene and demonstrates frequent occurrence in von Hippel-Lindau (VHL) disease. While this entity is designated CNS World Health Organization grade 1, due to its predilection for the cerebellum, brainstem, and spinal cord, it is still an important cause of morbidity and mortality in affected patients. Recognition and accurate diagnosis of hemangioblastoma is essential for the practice of surgical neuropathology. Other CNS neoplasms, including several tumors associated with VHL disease, may present as histologic mimics, making diagnosis challenging. We outline key clinical and radiologic features, pathophysiology, treatment modalities, and prognostic information for hemangioblastoma, and provide a thorough review of the gross, microscopic, immunophenotypic, and molecular features used to guide diagnosis.

The Role of Propranolol as a Repurposed Drug in Rare Vascular Diseases

Rare Diseases (RD) are defined by their prevalence in less than 5 in 10,000 of the general population. Considered individually, each RD may seem insignificant, but together they add up to more than 7000 different diseases. Research in RD is not attractive for pharmaceutical companies since it is unlikely to recover development costs for medicines aimed to small numbers of patients. Since most of these diseases are life threatening, this fact underscores the urgent need for treatments. Drug repurposing consists of identifying new uses for approved drugs outside the scope of the original medical indication. It is an alternative option in drug development and represents a viable and risk-managed strategy to develop for RDs. In 2008, the “off label” therapeutic benefits of propranolol were described in the benign tumor Infantile Hemangioma. Propranolol, initially prescribed for high blood pressure, irregular heart rate, essential tremor, and anxiety, has, in the last decade, shown increasing evidence of its antiangiogenic, pro-apoptotic, vasoconstrictor and anti-inflammatory properties in different RDs, including vascular or oncological pathologies. This review highlights the finished and ongoing trials in which propranolol has arisen as a good repurposing drug for improving the health condition in RDs.

Pathogenic ATM and BAP1 germline mutations in a case of early-onset, familial sarcomatoid renal cancer

Metastatic renal cell carcinoma (RCC) remains an incurable malignancy, despite recent advances in systemic therapies. Genetic syndromes associated with kidney cancer account for only 5%-8% of all diagnosed kidney malignancies, and genetic predispositions to kidney cancer predisposition are still being studied. Genomic testing for kidney cancer is useful for disease molecular subtyping but provides minimal therapeutic information. Understanding how aberrations drive RCC development and how their contextual influences, such as chromosome loss, genome instability, and DNA methylation changes, may alter therapeutic response is of importance. We report the case of a 36-yr-old female with aggressive, metastatic RCC and a significant family history of cancer, including RCC. This patient harbors a novel, pathogenic, germline ATM mutation along with a rare germline variant of unknown significance in the BAP1 gene. In addition, somatic loss of heterozygosity (LOH) in BAP1 and ATM genes, somatic mutation and LOH in the VHL gene, copy losses in Chromosomes 9p and 14, and genome instability are also noted in the tumor, potentially dictating this patient's aggressive clinical course. Further investigation is warranted to evaluate the association of ATM and BAP1 germline mutations with increased risk of RCC and if these mutations should lead to enhanced and early screening.

Elongin C (ELOC/TCEB1)-associated von Hippel-Lindau disease

Around 95% of patients with clinical features that meet the diagnostic criteria for von Hippel-Lindau disease (VHL) have a detectable inactivating germline variant in VHL. The VHL protein (pVHL) functions as part of the E3 ubiquitin ligase complex comprising pVHL, elongin C, elongin B, cullin 2 and ring box 1 (VCB-CR complex), which plays a key role in oxygen sensing and degradation of hypoxia-inducible factors. To date, only variants in VHL have been shown to cause VHL disease. We undertook trio analysis by whole-exome sequencing in a proband with VHL disease but without a detectable VHL mutation. Molecular studies were also performed on paired DNA extracted from the proband's kidney tumour and blood and bioinformatics analysis of sporadic renal cell carcinoma (RCC) dataset was undertaken. A de novo pathogenic variant in ELOC NM_005648.4(ELOC):c.236A>G (p.Tyr79Cys) gene was identified in the proband. ELOC encodes elongin C, a key component [C] of the VCB-CR complex. The p.Tyr79Cys substitution is a mutational hotspot in sporadic VHL-competent RCC and has previously been shown to mimic the effects of pVHL deficiency on hypoxic signalling. Analysis of an RCC from the proband showed similar findings to that in somatically ELOC-mutated RCC (expression of hypoxia-responsive proteins, no somatic VHL variants and chromosome 8 loss). These findings are consistent with pathogenic ELOC variants being a novel cause for VHL disease and suggest that genetic testing for ELOC variants should be performed in individuals with suspected VHL disease with no detectable VHL variant.

VHL mosaicism: the added value of multi-tissue analysis

Von Hippel-Lindau disease (VHL) is an autosomal dominant, inherited syndrome with variants in the VHL gene causing predisposition to multi-organ benign and malignant neoplasms. A germline VHL variant is identified in 95-100% of individuals with a clinical diagnosis of VHL. Here, we present the case of an individual with a clinical diagnosis of VHL disease where peripheral blood DNA analysis did not detect a VHL variant. Sequencing of four tumor tissues (ccRCC, pheochromocytoma, lung via sputum, liver) revealed a VHL c.593 T > C (p.Leu198Pro) variant at varying allele fractions (range: 10-55%) in all tissues. Re-examination of the peripheral blood sequencing data identified this variant at 6% allele fraction. Tumor analysis revealed characteristic cytomorphological, immunohistochemical reactivity for alpha-inhibin, and CAIX, and reduced pVHL reactivity supported VHL-related pseudohypoxia. This report of a rare case of VHL mosaicism highlights the value of tissue testing in VHL variant negative cases.

Familial multiple sclerosis in patients with Von Hippel-Lindau disease

Background

Multiple sclerosis (MS) is a progressive autoimmune demyelinating disorder. Recent studies suggest that a combination of genetic susceptibility and environmental insult contributes to its pathogenesis. Many candidate genes have been discovered to modulate susceptibility for developing MS by genome wide association studies (GWAS); these include major histocompatibility complex (MHC) genes and non-MHC genes. MS cases in the context of genetic diseases may provide different approaches and clues towards identifying novel genes and pathways involved in MS pathogenesis. Here, we present a case series of two related patients with concomitant Von Hippel-Lindau disease (VHLD) and MS.

Case presentation

We present two patients, a mother (case 1) and daughter (case 2), who developed superimposed relapsing-remitting multiple sclerosis in the background of the autosomal dominant genetic disorder VHLD. Several tumors characteristic of VHLD developed in both cases with pancreatic and renal neoplasms and cerebellar hemangioblastomas. In addition, both patients developed clinical symptoms consistent with multiple sclerosis, supported by radiologic lesions disseminating in time and space.

Conclusion

Though non-MHC susceptibility genes remain elusive in MS, we present the striking finding of superimposed multiple sclerosis in a mother and daughter with VHLD. The VHL gene is known to be the primary regulator of Nrf2, the well-established target of the FDA-approved therapeutic dimethyl fumarate. These cases provide support for further studies to determine whether VHLD pathway related genes represent a novel genetic link in multiple sclerosis.

Pheochromocytoma and paraganglioma: germline genetics and hereditary syndromes

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are neuroendocrine tumors arising from the adrenal medulla and extra-adrenal ganglia, respectively. Approximately 15-25% of PCC/PGL can become metastatic. Up to 30-40% of patients with PCC/PGL have a germline pathogenic variant in a known susceptibility gene for PCC/PGL; therefore, all patients with PCC/PGL should undergo clinical genetic testing. Most of the susceptibility genes are associated with variable penetrance for PCC/PGL and are associated with different syndromes, which include susceptibility for other tumors and conditions. The objective of this review is to provide an overview of the germline susceptibility genes for PCC/PGL, the associated clinical syndromes, and recommended surveillance.

Clinical characteristics and risk factors for survival in affected offspring of von Hippel-Lindau disease patients

Background

Von Hippel-Lindau (VHL) disease is an autosomal dominant genetic tumour syndrome with poor prognosis. The clinical manifestation was found to be more serious in affected offspring of patients with VHL disease, but the risk factors and survival for them have never been reported before. We aimed to explore how these patients were influenced by genetic and clinical factors.

Methods

In this retrospective study, we collected 372 affected offspring of VHL patients from 118 unrelated VHL families. Patients were stratified into different groups based on sets of variables. The age-related risk, overall survival and central nervous systemhaemangioblastoma (CHB)-specific survival were analysed between different groups using Kaplan-Meier survival analysis and Cox regression analysis.

Results

The estimated median life expectancy and median age of onset for affected offspring of VHL patients were 66 years and 28 years, respectively. The later generation and patients with mutations in exon 3 had an earlier onset age. The first presenting symptom was the only independent risk factor influencing overall survival and CHB-specific survival. Patients that the first presenting symptom is central nervous system (CNS) significantly had a lower life expectancy both in overall survival and CHB-specific survival analysis than abdominal lesions group.

Conclusion

This study indicated that affected offspring of VHL patients with CNS as the first presenting symptom was an independent risk factor for overall survival and CHB-specific survival. Generation and mutation region only had an effect on the onset age, which is helpful to clinical decision-making and generate a more precise surveillance protocol.

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.

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.

Multimodal image-guided ablation on management of renal cancer in Von-Hippel-Lindau syndrome patients from 2004 to 2021 at a specialist centre: A longitudinal observational study

OBJECTIVES

To analyse the safety, technical feasibility, long-term renal function and oncological outcome of multimodal technologies in image-guided ablation (IGA) for renal cancer in Von-Hippel-Lindau (VHL) patients, and to evaluate factors that may influence the outcome.

METHODS

Retrospective analysis of a prospective database of VHL patients who underwent IGA at a specialist centre. Patient's demographics, treatment energy, peri-operative outcome and oncological outcomes were recorded. Statistical analysis was performed to determine factors associated with complication and renal function reduction. The overall, 5 and 10-year cancer specific (CS), local recurrence-free (LRF) and metastasis-free (MF) survival rates were presented with Kaplan-Meier Curves.

RESULTS

From 2004 to 2021, 17 VHL patients (age 21-68.2) with a mean (±SD) RCC size of 2.06 ± 0.92 cm received IGA. Median (IQR) RCCs per patient was 3 (2-4) over the course of follow up. Fifty-four RCCs were treated using radiofrequency ablation (n = 11), cryoablation (n = 38) and irreversible electroporation (n = 8) in 50 sessions. Primary and overall technical success rate were 94.4% (51/54) and 98% (53/54). One CD-III complication with proximal ureteric injury. Five patients in seven treatment sessions experienced a >25% reduction of eGFR immediately post-IGA. All patients have preservation of renal function at a median follow-up of 79 (51-134) months. The 5 and 10-year CS, LRF and MF survival rates are 100%, 97.8% and 100%. Whilst, the 5 and 10-year overall survival rate are100% and 90%.

CONCLUSION

Multimodal IGA of de novo RCC for VHL patients is safe and has provided long term preservation of renal function and robust oncological durability.

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.

A Tale of Two Organ Systems: Imaging Review of Diseases Affecting the Thoracic and Neurological Systems. Part 2

In an era of rapidly expanding knowledge and sub-specialization, it is becoming increasingly common to focus on one organ system. However, the human body is intimately linked, and disease processes affecting one region of the body not uncommonly affect the other organ systems as well. Understanding diseases from a macroscopic perspective, rather than a narrow vantage point, enables efficient and accurate diagnosis. This tenet holds true for diseases affecting both the thoracic and neurologic systems; in isolation, the radiologic appearance of disease in one organ system may be nonspecific, but viewing the pathophysiologic process in both organ systems may markedly narrow the differential considerations, and potentially lead to a definitive diagnosis. In this article, we discuss a variety of disease entities known to affect both the thoracic and neurological systems, either manifesting simultaneously or at different periods of time. Some of these conditions may show neither thoracic nor neurological manifestations. These diseases have been systematically classified into infectious, immune-mediated/ inflammatory, vascular, syndromic/ hereditary and neoplastic disorders. The underlying pathophysiological mechanisms linking both regions and radiologic appearances in both organ systems are discussed. When appropriate, brief clinical and diagnostic information is provided. Ultimately, accurate diagnosis will lead to expedited triage and prompt institution of potentially life-saving treatment for these groups of complex disorders.

Regulation of Cancer Metabolism by Deubiquitinating Enzymes: The Warburg Effect

Cancer is a disorder of cell growth and proliferation, characterized by different metabolic pathways within normal cells. The Warburg effect is a major metabolic process in cancer cells that affects the cellular responses, such as proliferation and apoptosis. Various signaling factors down/upregulate factors of the glycolysis pathway in cancer cells, and these signaling factors are ubiquitinated/deubiquitinated via the ubiquitin-proteasome system (UPS). Depending on the target protein, DUBs act as both an oncoprotein and a tumor suppressor. Since the degradation of tumor suppressors and stabilization of oncoproteins by either negative regulation by E3 ligases or positive regulation of DUBs, respectively, promote tumorigenesis, it is necessary to suppress these DUBs by applying appropriate inhibitors or small molecules. Therefore, we propose that the DUBs and their inhibitors related to the Warburg effect are potential anticancer targets.

Iatrogenic ureteric stricture post image guided renal cryoablation in a patient with von hippel-lindau syndrome

A 53-year-old lady is known to have Von Hippel-Lindau syndrome with a long history of previous renal cell carcinomas (RCCs) in both kidneys. She was treated by partial nephrectomy for a right peripheral RCC and subsequently image guided radiofrequency ablation (RFA) of a left central RCC. She developed another de novo RCC adjacent to the right pelvic-ureteric junction (PUJ) 4 years after the initial RFA. Due to the close proximity to the PUJ and visibility of an ice ball with cryoablation (CRYO), the consensus from the MDT was that CRYO would be safer than RFA and she subsequently underwent percutaneous image guided CRYO to treat the small de novo RCC. Unfortunately, during the 1-month imaging follow up, she developed moderate hydronephrosis and a ureteric stricture needing long-term ureteric stent management. This case highlights the risk of ureteric injury caused by the thermal effect of the ice ball during image guided renal CRYO. Therefore, it is vital that all interventional radiologists adopt various manoeuvres to protect the ureter from the ice ball during CRYO in order to avoid the development of latent ureteric stricture.

Von Hippel-Lindau disease and rapidly progressing pheochromocytomas in siblings

Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited condition with a predisposition to the development of a variety of tumors including pheochromocytomas. A number of cancer surveillance protocols for patients with VHL have been developed, all of which are based on expert opinion. We report a case of two brothers with a strong family history of VHL type 2 due to a pathogenic germline VHL variant, specifically, a surface missense substitution, with a rapidly progressive clinical course that both presented with a large adrenal mass. Both brothers presented with large pheochromocytomas, the earliest presentation being at age 7, despite routine screening. The rapid progression and early presentation of these patients raises an important discussion around the commonly used surveillance protocols for pheochromocytoma in pediatric patients with VHL and missense mutations. We conclude that a more accelerated surveillance protocol may be adequate for VHL families with a high pheochromocytoma risk.

Imaging evaluation of hereditary renal tumors: a pictorial review

More than 10 hereditary renal tumor syndromes (HRTSs) and related germline mutations have been reported with HRTS-associated renal and extrarenal manifestations with benign and malignant tumors. Radiologists play an important role in detecting solitary or multiple renal masses with or without extrarenal findings on imaging and may raise the possibility of an inherited predisposition to renal cell carcinoma, providing direction for further screening, intervention and surveillance of the patients and their close family members before the development of potentially lethal renal and extrarenal tumors. Renal cell carcinomas (RCCs) associated with von Hippel-Lindau disease are typically slow growing while RCCs associated with HRTSs, such as hereditary leiomyomatosis and renal cell carcinoma syndrome, are highly aggressive. Therefore, radiologists need to be familiar with clinical and imaging findings of renal and extrarenal manifestations of HRTSs. This article reviews clinical and imaging findings for the evaluation of patients with well-established HRTSs from a radiologist's perspective to facilitate the clinical decision-making process for patient management.

A review of inherited cancer susceptibility syndromes

Inherited cancer syndromes are caused by genetic mutations that place patients at an increased risk for developing cancer. Although most cancers are not caused by genetic inheritance, clinicians must understand these syndromes and be able to recognize their common characteristics. A thorough family history and identification of common patterns as well as specific clinical signs and symptoms can help with early recognition. This article describes symptoms of the more common cancer syndromes, including hereditary breast and ovarian cancer, Li-Fraumeni, Lynch, familial adenomatous polyposis, retinoblastoma, multiple endocrine neoplasia, and von Hippel-Lindau. Important patient education regarding genetic testing also is covered.

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.

VON HIPPEL-LINDAU DISEASE: Update on Pathogenesis and Systemic Aspects

PURPOSE

To provide an update summarizing the biologic pathways governing von Hippel-Lindau (VHL) disease pathogenesis and to provide an overview of systemic manifestations as well as screening recommendations.

METHODS

A PubMed search of the English language literature was reviewed using the following search terms: von Hippel-Lindau, von Hippel-Lindau disease, and VHL. Of 6,696 publications, the most current and pertinent information related to the pathogenesis and systemic aspects of VHL disease were included in this review.

RESULTS

von Hippel-Lindau disease is one of the most frequently occurring multisystem familial cancer syndromes. The disease results from germline mutation in the VHL tumor suppressor gene on the short arm of chromosome 3. Mutation in the VHL gene affects multiple cellular processes including transcriptional regulation, extracellular matrix formation, apoptosis, and, in particular, the cellular adaptive response to hypoxia. As a result, there is widespread development of vascular tumors affecting the retina, brain, and spine, as well as a spectrum of benign and malignant tumors and/or cysts in visceral organs.

CONCLUSION

The ophthalmologist plays a key role in VHL disease diagnosis, as retinal hemangioblastoma is frequently the first disease manifestation. Screening guidelines for individuals with known VHL disease, and those at risk of VHL disease, help to ensure early detection of potentially vision-threatening and life-threatening disease.

Von Hippel-Lindau Disease: Current Challenges and Future Prospects

Understanding of molecular mechanisms of tumor growth has an increasing impact on the development of diagnostics and targeted therapy of human neoplasia. In this review, we summarize the current knowledge on molecular mechanisms and their clinical implications in von Hippel-Lindau (VHL) disease. This autosomal dominant tumor syndrome usually manifests in young adulthood and predisposes affected patients to the development of benign and malignant tumors of different organ systems mainly including the nervous system and internal organs. A consequent screening and timely preventive treatment of lesions are crucial for patients affected by VHL disease. Surgical indications and treatment have been evaluated and optimized over many years. In the last decade, pharmacological therapies have been evolving, but are largely still at an experimental stage. Effective pharmacological therapy as well as detection of biomarkers is based on the understanding of the molecular basis of disease. The molecular basis of von Hippel-Lindau disease is the loss of function of the VHL protein and subsequent accumulation of hypoxia-inducible factor with downstream effects on cellular metabolism and differentiation. Organs affected by VHL disease may develop frank tumors. More characteristically, however, they reveal multiple separate microscopic foci of neoplastic cell proliferation. The exact mechanisms of tumorigenesis in VHL disease are, however, still not entirely understood and knowledge on biomarkers and targeted therapy is scarce.

CLN5 in heterozygosis may protect against the development of tumors in a VHL patient

Von Hippel-Lindau syndrome (VHL) is a rare disease of dominant inheritance that increases susceptibility to tumor development, with a complete penetrance at the age of 60. In this report, we present the unprecedented case of a VHL carrier who remains healthy at 72. Under the course of this study, it was discovered that this patient carries a mutation for a second rare disease, Neuronal Ceroid Lipofuscinosis (NCL or CNL). We hypothesize that the CLN mutation she carries offers a protective effect, preventing tumor development in the cells potentially suffering a VHL second hit mutation. To test this hypothesis, we ran a series of molecular experiments and confirmed that cell viability of primary endothelial cells decreases upon CLN5 silencing. Our results further elucidate the cell biology implications of two rare diseases interacting.

Genetic and epigenetic alterations in pancreatic neuroendocrine tumors

Neuroendocrine tumors (NETs) are a heterogenous group of tumors that originate from neuroendocrine cells, mainly in the pancreas and the gastrointestinal and bronchopulmonary tracts. There has been considerable progress in our understanding of the genetic and epigenetic changes associated with pancreatic NETs (PNETs). The main genetic alterations that drive PNETs include genetic alterations in MEN1, VHL and genes involved in the mTOR pathway, DAXX and/or ATRX mutations and their association with alternative telomere lengthening, and genes involved in DNA damage repair and chromatin modification. The epigenetic alterations in PNETs are also common based on genome-wide DNA methylation profiling studies, with a high rate of CpG hypermethylation in MEN1-associated PNETs compared to sporadic and VHL-associated PNETs. Moreover, the dysregulated DNA methylation status is associated with distinct gene expression profiles. This article reviews the commonly and recently discovered genetic and epigenetic changes that are associated with PNETs, inherited PNETs, and genotype-phenotype associations, and it discusses their clinical relevance.

Inherited syndromes involving pancreatic neuroendocrine tumors

Inherited syndromes are important to recognize in the setting of a pancreatic neuroendocrine tumor (PNET) as there are significant implications for the patient's medical management and opportunity for early detection of subsequent manifestations. Although most PNETs are sporadic, approximately 10% are due to an inherited syndrome, which include multiple endocrine neoplasia type 1 (MEN1), multiple endocrine neoplasia type 4 (MEN4), von Hippel-Lindau disease (VHL), neurofibromatosis type 1 (NF1), and tuberous sclerosis complex (TSC). The general hallmarks of a hereditary endocrine neoplasia predisposition syndrome include any one of the following: multiple primary tumors (in the same or different organs), rare tumors (prevalence of less than 1 in 1,000 people in the general population), earlier age of diagnosis (usually under the age of 40), characteristic pattern of disease in the individual or family (phenotype and inheritance pattern). These syndromes are monogenic (due to a single gene disorder), highly penetrant (with all carriers of the disease exhibiting at least part of the phenotype) and can display variable expressivity (where affected individuals may have different presentations and features of the disease). A thoughtful approach to management is required, even if the presenting symptom is resolved, as these syndromes often involve multi-organ disease with a lifelong risk for tumor development. Additionally, the natural history of tumors in the setting of a hereditary condition may be different than would be expected in a sporadic form of the disease. For example, in some circumstances the risk of metastatic disease is lower, and therefor longer observation is the preferred approach over early surgical intervention. The unique aspects to management, challenges in hereditary disease recognition and accurate diagnosis, and rarity of these syndromes are all reasons to support referral to high-volume centers with the experience and knowledge to treat patients with hereditary endocrine neoplasia syndromes.

Biomarkers for Pancreatic Neuroendocrine Neoplasms (PanNENs) Management-An Updated Review

Pancreatic neuroendocrine tumors (PanNENs) are rare sporadic cancers or develop as part of hereditary syndromes. PanNENs can be both functioning and non-functioning based on whether they produce bioactive peptides. Some PanNENs are well differentiated while others-poorly. Symptoms, thus, depend on both oncological and hormonal causes. PanNEN diagnosis and treatment benefit from and in some instances are guided by biomarker monitoring. However, plasmatic monoanalytes are only suggestive of PanNEN pathological status and their positivity is typically followed by deepen diagnostic analyses through imaging techniques. There is a strong need for new biomarkers and follow-up modalities aimed to improve the outcome of PanNEN patients. Liquid biopsy follow-up, i.e., sequential analysis on tumor biomarkers in body fluids offers a great potential, that need to be substantiated by additional studies focusing on the specific markers and the timing of the analyses. This review provides the most updated panorama on PanNEN biomarkers.