VHL disease

Metabolomic landscape of renal cell carcinoma in von Hippel-Lindau syndrome in a Chinese cohort

Von Hippel-Lindau (VHL) syndrome is a rare autosomal dominant disorder, where renal cell carcinoma (RCC) serves as a significant cause of mortality. We collected peripheral blood from 61 VHL-RCC patients and 31 healthy individuals, along with 19 paired RCC tumor and adjacent non-malignant samples. Using liquid chromatography-mass spectrometry, we identified 238 plasma and 241 tissue differentially abundant metabolites (DAMs), highlighting key pathways such as arginine and proline metabolism. The top 10 of the 23 DAMs, common to both plasma and tissue, were instrumental in constructing a high-performance diagnostic model. These DAMs demonstrated significant correlations with VHL gene mutation types. Cox regression analysis revealed that plasma levels of N2,N2-dimethylguanosine were associated with the timing of RCC onset in VHL patients, acting as an independent predictive factor. This study enhances diagnostic accuracy for this rare condition and opens new avenues for exploring metabolic mechanisms of the disease and potential therapeutic directions.

Genotype–phenotype correlations and clinical outcomes of patients with von Hippel-Lindau disease with large deletions

Background

Approximately 20%–40% of patients with von Hippel-Lindau (VHL) disease, an autosomal dominant hereditary disease, exhibit large deletions (LDs). Few studies have focused on this population. Hence, we aimed to elucidate the genotype–phenotype correlations and clinical outcomes in VHL patients with LDs.

Methods

In this retrospective study, we included 119 patients with VHL disease from 50 unrelated families in whom LDs were detected using traditional and next-generation sequencing methods. Other germline mutations were confirmed by Sanger sequencing. Genotype–phenotype correlations and survival were analysed in different groups using Kaplan-Meier and Cox regression. We also evaluated therapeutic response to tyrosine kinase inhibitor (TKI) therapy.

Results

The overall penetrance of patients aged <60 was 95.2%. Two VHL patients with LDs also carried CHEK2 and FLCN germline mutations. An earlier age of onset of retinal haemangioblastoma was observed in the next generation. Patients with exon 2 deletion of VHL had an earlier onset age of renal cell carcinoma and pancreatic lesions. The risk of renal cell carcinoma was lower in VHL patients with LDs and a BRK1 deletion. The group with earlier age of onset received poorer prognosis. Four of eight (50%) patients showed partial response to TKI therapy.

Conclusion

The number of generations and the status of exon 2 could affect age of onset of VHL-related manifestations. Onset age was an independent risk factor for overall survival. TKI therapy was effective in VHL patients with LDs. Our findings would further support clinical surveillance and decision-making processes.

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.

Synchronous Presentation of Rare Brain Tumors in Von Hippel-Lindau Syndrome

Von Hippel-Lindau (VHL) disease is a heritable cancer syndrome in which benign and malignant tumors and/or cysts develop throughout the central nervous system (CNS) and visceral organs. The disease results from mutations in the VHL tumor suppressor gene located on chromosome 3 (3p25-26). A majority of individuals (60-80%) with VHL disease will develop CNS hemangioblastomas (HMG). Endolymphatic sac tumor (ELST) is an uncommon, locally aggressive tumor located in the medial and posterior petrosal bone region. Its diagnosis is based on clinical, radiological, and pathological correlation, and it can occur in the setting of VHL in up to 10-15% of individuals. We describe a 17-year-old male who presented with a chief complaint of hearing loss. Brain and spine Magnetic Resonance Imaging documented the presence of an expansive lesion in the left cerebellar hemisphere, compatible with HMG in association with a second cerebellopontine lesion compatible with ELST. The peculiarity of the reported case is due to the simultaneous presence of two typical characteristics of VHL, which led to performing comprehensive genetic testing, thus allowing for the diagnosis of VHL. Furthermore, ELST is rare before the fourth decade of life. Early detection of these tumors plays a key role in the optimal management of this condition.

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.

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.

A synonymous VHL variant in exon 2 confers susceptibility to familial pheochromocytoma and von Hippel-Lindau disease

CONTEXT

von Hippel-Lindau disease, comprising renal cancer, hemangioblastoma and/or pheochromocytoma (PHEO) is caused by missense or truncating variants of the VHL tumor suppressor gene, which is involved in degradation of hypoxia inducible factors (HIFs). However, the role of synonymous VHL variants in the disease is unclear.

OBJECTIVE

We evaluated a synonymous VHL variant in patients with familial PHEO or VHL disease without a detectable pathogenic VHL mutation.

DESIGN

We performed genetic and transcriptional analyses of leukocytes and/or tumors from affected and unaffected individuals and evaluated VHL splicing in existing cancer databases.

RESULTS

We identified a synonymous VHL variant(c.414A>G, p.Pro138Pro) as the driver event in five independent individuals/families with PHEOs or VHL syndrome. This variant promotes exon 2 skipping and, hence, abolishes expression of the full-length VHL transcript. Exon 2 spans the HIF binding domain, required for HIF degradation by VHL. Accordingly, PHEOs carrying this variant display HIF hyperactivation typical of VHL loss. Moreover, other exon 2 VHL variants from the TCGA pan-cancer datasets are biased toward expression of a VHL transcript that excludes this exon, supporting a broader impact of this spliced variant.

CONCLUSION

A recurrent synonymous VHL variant (c.414A>G, p.Pro138Pro) confers susceptibility to PHEO and VHL disease through splice disruption, leading to VHL dysfunction. This finding indicates that certain synonymous VHL variants may be clinically relevant and should be considered in genetic testing and surveillance settings. The observation that other coding VHL variants can exclude exon 2 suggests that dysregulated splicing may be an underappreciated mechanism in VHL-mediated tumorigenesis.

Bilateral Pheochromocytomas in a Patient with Y175C Von Hippel-Lindau Mutation

Von Hippel-Lindau (VHL) disease, caused by germline mutations in the VHL gene, is characterized by metachronously occurring tumors including pheochromocytoma, renal cell carcinoma (RCC), and hemangioblastoma. Although VHL disease leads to reduced life expectancy, its diagnosis is often missed and tumor screening guidelines are sparse. VHL protein acts as a tumor suppressor by targeting hypoxia-inducible factors (HIFs) for degradation through an oxygen-dependent mechanism. VHL mutants with more severely reduced HIF degrading function carry a high risk of RCC, while mutants with preserved HIF degrading capacity do not cause RCC but still lead to other tumors. VHL disease is classified into clinical types (1 and 2A-2C) based on this genotype-phenotype relationship. We report a case of bilateral pheochromocytomas and no other VHL-related tumors in a patient with Y175C VHL and show that this mutant preserves the ability to degrade HIF in normal oxygen conditions but, similar to the wild-type VHL protein, loses its ability to degrade HIF under hypoxic conditions. This study adds to the current understanding of the structure-function relationship of VHL mutations, which is important for risk stratification of future tumor development in the patients.

Impact of Estrogen on the Relationship Between Obesity and Renal Cell Carcinoma Risk in Women

The relationship between obesity and renal cell carcinoma (RCC) has been widely investigated. However, the effect of estrogen on this relationship in female RCC patients has not been evaluated. We conducted a case-control study to investigate the role of estrogen as a potential modifier of the association between obesity and RCC risk in Chinese women.

A total of 497 consecutive female patients with pathologically confirmed RCC, including 364 clear cell RCC (ccRCC), were enrolled. Age-matched controls were selected from cancer-free females seeking physical examination in our institution. Estrogen receptor-β (ER-β) and insulin-like growth factor (IGF)-1 receptor (IGF-1R) expression levels were detected in RCC tissues. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated by logistic regression models.

We observed a positive association between overweight and RCC risk in pre-menopausal but not post-menopausal women. Similar association was also observed between overweight and ccRCC risk. Overweight pre-menopausal women had an increased risk of RCC (OR: 1.67, 95%CI: 1.01–2.76), as well as an increased risk of ccRCC (OR: 1.73, 95%CI: 1.02–2.99), after adjusting for potential confounders. IGF-1R expression levels were higher in pre-menopausal compared with post-menopausal cases (P = 0.015).

These results suggest that estrogen plays an important role in RCC etiology and may modify the association between obesity and RCC risk in women. We hypothesize that estrogen may up-regulate IGF-1R and potentiate the deleterious effects of obesity-related elevations of insulin and IGFs.

Two Childhood Pheochromocytoma Cases due to von Hippel-Lindau Disease, One Associated with Pancreatic Neuroendocrine Tumor: A Very Rare Manifestation

von Hippel-Lindau (VHL) disease is an autosomal dominantly inherited disorder, characterized by hemangioblastomas of the retina and central nervous system (CNS); renal cysts; clear cell carcinoma; pheochromocytoma (PCC); endolymphatic sac tumors; cystadenomas of the epididymis in males; broad ligament of uterus in females; pancreatic cysts; cystadenomas; and neuroendocrine tumors. We report two cases of VHL disease that presented with PCC as the first manifestation. Further clinical developments during follow-up, hemangioblastoma of CNS in one case and a pancreatic neuroendocrine tumor (PNET) in the second case led to the diagnosis of VHL disease. Genetic analyses of the two cases revealed p.Arg161Gln (c.482G>A) and p.Leu129Pro (c.386T>G) heterozygous missense mutations in the VHL gene, respectively. In children, PCC may be the only and/or initial manifestation of VHL with delayed manifestations of the syndrome in other organs. PNET is a very rare manifestation of VHL disease. To the best of our knowledge, this is only the second reported case presenting with a combination of a PNET and bilateral PCC as components of childhood VHL disease. Pediatric patients diagnosed with PCC should be investigated for genetic causes and especially for VHL.

Looking beyond the thyroid: advances in the understanding of pheochromocytoma and hyperparathyroidism phenotypes in MEN2 and of non-MEN2 familial forms

Over the last years, the knowledge of MEN2 and non-MEN2 familial forms of pheochromocytoma (PHEO) has increased. In MEN2, PHEO is the second most frequent disease: the penetrance and age at diagnosis depend on the mutation of RET Given the prevalence of bilateral PHEO (50% by age 50), adrenal sparing surgery, aimed at sparing a part of the adrenal cortex to avoid adrenal insufficiency, should be systematically considered in patients with bilateral PHEO. Non-MEN2 familial forms of PHEO now include more than 20 genes: however, only small phenotypic series have been reported, suggesting that phenotypic features of isolated hereditary PHEO must be better explored, and follow-up series are needed to better understand the outcome of patients carrying mutations of these genes. The first part of this review will mainly focus on these points. In the second part, a focus will be given on MEN2 and non-MEN2 familial forms of hyperparathyroidism (HPTH). Again, the management of MEN2 HPTH should be aimed at curing the disease while preserving an optimal quality of life by a tailored parathyroidectomy. The phenotypes and outcome of MEN1-, MEN4- and HRPT2-related HPTH are briefly described, with a focus on the most recent literature data and is compared with familial hypocalciuric hypercalcemia.

Von Hippel-Lindau disease: a single gene, several hereditary tumors

The Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder characterized by the predisposition for multiple tumors caused by germline mutations in the tumor suppressor gene VHL. This disease is associated with a high morbidity and mortality and presents a variable expression, with different phenotypes from family to family, affecting different organs during the lifetime. The main manifestations of VHL are hemangioblastomas of the central nervous system and retina, renal carcinomas and cysts, bilateral pheochromocytomas, cystic and solid tumors of the pancreas, cystadenomas of the epididymis, and endolymphatic sac tumors. The discovery of any of the syndrome components should raise suspicion of this disease and other stigmas must then be investigated. Due to the complexities associated with management of the various VHL manifestation, the diagnosis and the follow-up of this syndrome is a challenge in the clinical practice and a multidisciplinary approach is needed. The particular relevance to endocrinologists is the detection of pheochromocytomas in 35% and islet cell tumors in 17% of VHL patients, which can be associated with hypertension, hypoglycemia, cardiac arrhythmias, and carcinoid syndrome. The purpose of this review is to define the Von Hippel-Lindau syndrome addressing its clinical aspects and classification, the importance of genetic counseling and to propose a protocol for clinical follow-up.

Functional variants in the low-density lipoprotein receptor gene are associated with clear cell renal cell carcinoma susceptibility

Recent studies indicate that abnormal levels of low-density lipoprotein (LDL), which is an important component of dyslipidaemia, are associated with alterations to cancer risk, including that of renal cell carcinoma (RCC). Single nucleotide polymorphisms at microRNA-binding sites contribute to cancer susceptibility and progression by affecting the messenger RNA (mRNA) function of target genes. In this case-control study, we examined the frequency of six potentially functional single nucleotide polymorphisms in the LDL receptor gene (LDLR) in 1004 clear cell RCC (ccRCC) patients and 1065 cancer-free subjects. Logistic regression analyses estimated odds ratios (ORs) and 95% confidence intervals (CIs). The association between genetic variants and levels of LDLR mRNA and protein was also evaluated. Compared with the CC genotype, multivariate logistic regression analysis showed that the LDLR rs2738464 variant GG genotype was associated with a significantly decreased ccRCC risk (P = 0.002, OR: 0.605, 95% CI: 0.439-0.833). Further functional experiments showed that the rs2738464 variant G allele affected miR-330 regulation of the LDLR 3'-untranslated region (UTR), increasing LDLR mRNA levels in patient kidney tissues. These findings suggest that LDLR rs2738464 may affect the affinity of miR-330 binding to the LDLR 3'-UTR, thus regulating LDLR expression and contributing to ccRCC risk.

Management Strategies and Outcomes for VHL-related Craniospinal Hemangioblastomas

Hemangioblastomas are rare and benign tumors accounting for less than 2% of all central nervous system (CNS) tumors. The vast majority of hemangioblastomas occur sporadically, whereas a small number of cases, especially in younger patients, are associated with Von Hippel–Lindau (VHL) syndrome. It is thought that loss of tumor suppressor function of the VHL gene results in stabilization of hypoxia-inducible factor alpha with downstream activation of cellular proliferative and angiogenic genes that promote tumorigenesis. VHL-related hemangioblastomas predominantly occur in the cerebellum and spine. Lesions are often diagnosed on contrast-enhanced craniospinal MRIs, and the diagnosis of VHL occurs through assessment for germline VHL mutations. Surgical resection remains the primary treatment modality for symptomatic or worrisome lesions, with excellent local control rates and neurological outcomes. Stereotactic radiotherapy can be employed in patients who are deemed high risk for surgery, have multiple lesions, or have non-resectable lesions. Given the tendency for development of either new or multiple lesions, close radiographic surveillance is often recommended for asymptomatic lesions.

Heritable Cancer Syndromes Related to the Hypoxia Pathway

Families of tumor-suppressor genes, such as those involved in homologous recombination or mismatch repair, contain individual genes implicated in hereditary cancer syndromes. Collectively, such groupings establish that inactivating germline changes in genes within pathways related to genomic repair can promote carcinogenesis. The hypoxia pathway, whose activation is associated with aggressive and resistant sporadic tumors, is another pathway in which tumor-suppressor genes have been identified. von Hippel–Lindau disease, some of the hereditary paraganglioma–pheochromocytoma (PGL/PCC) syndromes, and the syndrome of hereditary leiomyomatosis and renal cell carcinoma are heritable conditions associated with genes involved or associated with the hypoxia pathway. This review links these heritable cancer syndromes to the hypoxia pathway while also comparing the relative aggression and treatment resistance of syndrome-associated tumors to similar, sporadic tumors. The reader will become aware of shared phenotypes (e.g., PGL/PCC, renal cell carcinoma) among these three hypoxia-pathway-associated heritable cancer syndromes as well as the known associations of tumor aggressiveness and treatment resistance within these pathways.

Pheochromocytoma Screening Initiation and Frequency in von Hippel-Lindau Syndrome

CONTEXT

Patients with von Hippel-Lindau (VHL) syndrome have a 25-30% chance of developing pheochromocytoma. Although practice guidelines recommend biochemical and radiological screening every 1-2 years for pheochromocytoma in patients with VHL, there are limited data on the optimal age and frequency for screening.

OBJECTIVE

Our objective was to determine the earliest age of onset and frequency of contralateral and recurrent pheochromocytomas in patients with VHL syndrome.

METHODS

This is a retrospective analysis of a prospective cohort of patients with VHL enrolled in a natural history study.

RESULTS

A total of 273 patients diagnosed with VHL were enrolled in a natural history clinical study. Thirty-one percent (84) were diagnosed with pheochromocytoma. The mean age of diagnosis was 28.8 ± 13.9 years. The earliest age at diagnosis was 5.5 years. Median follow-up for the cohort was 116.6 months (range, 0.1-613.2). Ninety-nine percent (83) of patients underwent adrenalectomy. Fifty-eight and 32% of patients had metanephrines and/or catecholamines elevated more than two times and more than four times the upper limit of normal, respectively. Twenty-five percent (21) of pheochromocytomas were diagnosed in pediatric patients younger than 19 years of age, and 86% and 57% of pediatric patients had an elevation more than two times and more than four times upper limit of normal, respectively. Eight patients had a total of nine recurrences. The median age at recurrence was 33.5 years (range, 8.8-51.9). Recurrences occurred as short as 0.5 years and as long as 39.7 years after the initial operation.

CONCLUSIONS

Our findings among VHL pediatric patients supports the need for biochemical screening starting at age 5 with annual lifelong screening.

ADIPOQ polymorphism rs182052 is associated with clear cell renal cell carcinoma

Recent studies have indicated that low circulating adiponectin concentrations are associated with a higher risk of several cancers, including renal cell carcinoma. In this case–control study, we examined the frequency of single nucleotide polymorphisms (rs182052G>A, rs266729C>G, and rs3774262G>A) in the adiponectin gene (ADIPOQ) in 1004 patients with clear cell renal cell carcinoma (ccRCC) compared with a group of healthy subjects (n = 1108). Fasting serum adiponectin concentrations were also examined. Logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (95% CI). The association of serum adiponectin concentration with genetic variants was calculated using a multivariate linear regression model. A significantly higher ccRCC risk was associated with the rs182052 variant A allele (adjusted OR, 1.36 and 95% CI, 1.07–1.74 for AA vs GG, P = 0.013; adjusted OR, 1.27 and 95% CI, 1.04–1.56 for AA vs GG+AG, P = 0.019), and this positive association was more evident in overweight subjects. Fasting serum adiponectin was lower in subjects carrying A alleles of rs182052 in both ccRCC patients (β = −0.399, P = 0.018) and healthy controls (β = −0.371, P = 0.024). These results suggest that ADIPOQ rs182052 is significantly associated with ccRCC risk.

In this case–control study, we examined the frequency of single nucleotide polymorphisms (rs182052G>A, rs266729C>G, and rs3774262G>A) in the adiponectin gene (ADIPOQ) in 1004 patients with clear cell RCC (ccRCC) compared with a group of healthy subjects (n = 1108). Fasting serum adiponectin concentrations were also examined. Fasting serum adiponectin was lower in subjects carrying minor alleles of rs182052 in both ccRCC patients (β = −0.399, P = 0.018) and healthy controls (β = −0.371, P = 0.024). These results suggest that ADIPOQ rs182052 is significantly associated with ccRCC risk.

Endocrine manifestations of von Hippel-Lindau disease

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

Implications of Von Hippel-Lindau Syndrome and Renal Cell Carcinoma

Von Hippel-Lindau syndrome (VHLS) is a rare hereditary neoplastic disorder caused by mutations in the vhl gene leading to the development of tumors in several organs including the central nervous system, pancreas, kidneys, and reproductive organs. Manifestations of VHLS can present at different ages based on the affected organ and subclass of disease. In the subclasses of VHLS that cause renal disease, renal involvement typically begins closer to the end of the second decade of life and can present in different ways ranging from simple cystic lesions to solid tumors. Mutations in vhl are most often associated with clear cell renal carcinoma, the most common type of renal cancer, and also play a major role in sporadic cases of clear cell renal carcinoma. The recurrent, multifocal nature of this disease presents difficult challenges in the long-term management of patients with VHLS. Optimization of renal function warrants the use of several different approaches common to the management of renal carcinoma such as nephron sparing surgery, enucleation, ablation, and targeted therapies. In VHLS, renal lesions of 3 cm or bigger are considered to have metastatic potential and even small lesions often harbor malignancy. Many of the aspects of management revolve around optimizing both oncologic outcome and long-term renal function. As new surgical strategies and targeted therapies develop, the management of this complex disease evolves. This review will discuss the key aspects of the current management of VHLS.

De novo VHL germline mutation detected in a patient with mild clinical phenotype of von Hippel-Lindau disease

Von Hippel-Lindau (VHL) disease is an autosomal dominant multiorgan tumor syndrome caused by a germline mutation in the VHL gene. Characteristic tumors include CNS hemangioblastomas (HBs), endolymphatic sac tumors, renal cell carcinomas, pheochromocytomas, and pancreatic neuroendocrine tumors. Sporadic VHL disease with a de novo germline mutation is rare. The authors describe a case of multiple CNS HBs in a patient with a heterozygous de novo germline mutation at c.239G>T [p.S80I] of VHL. This is the first known case of a sporadic de novo germline mutation of VHL at c.239G>T. Clinicians should continue to consider VHL disease in patients presenting with sporadic CNS HBs, including those without a family history, to confirm or exclude additional VHL-associated visceral lesions.

Pheochromocytoma and paraganglioma pathogenesis: learning from genetic heterogeneity

The neuroendocrine tumours pheochromocytomas and paragangliomas carry the highest degree of heritability in human neoplasms, enabling genetic alterations to be traced to clinical phenotypes through their transmission in families. Mutations in more than a dozen distinct susceptibility genes have implicated multiple pathways in these tumours, offering insights into kinase downstream signalling interactions and hypoxia regulation, and uncovering links between metabolism, epigenetic remodelling and cell growth. These advances extend to co-occurring tumours, including renal, thyroid and gastrointestinal malignancies. Hereditary pheochromocytomas and paragangliomas are powerful models for recognizing cancer driver events, which can be harnessed for diagnostic purposes and for guiding the future development of targeted therapies.

P.Arg82Leu von Hippel-Lindau (VHL) gene mutation among three members of a family with familial bilateral pheochromocytoma in India: molecular analysis and in silico characterization

Various missense mutations in the VHL gene have been reported among patients with familial bilateral pheochromocytoma. However, the p.Arg82Leu mutation in the VHL gene described here among patients with familial bilateral pheochromocytoma, has never been reported previously in a germline configuration. Interestingly, long-term follow-up of these patients indicated that the mutation might have had little impact on the normal function of the VHL gene, since all of them have remained asymptomatic. We further attempted to correlate this information with the results obtained by in silico analysis of this mutation using SIFT, PhD-SNP SVM profile, MutPred, PolyPhen2, and SNPs&GO prediction tools. To gain, new mechanistic insight into the structural effect, we mapped the mutation on to 3D structure (PDB ID 1LM8). Further, we analyzed the structural level changes in time scale level with respect to native and mutant protein complexes by using 12 ns molecular dynamics simulation method. Though these methods predict the mutation to have a pathogenic potential, it remains to be seen if these patients will eventually develop symptomatic disease.

A new germline VHL gene mutation in three patients with apparently sporadic pheochromocytoma

CONTEXT

Germline mutations in four genes (RET, VHL, SDHB and SDHD) are detected in about 17% of patients with apparently sporadic pheochromocytoma. Thus, genetic screening of all patients with this disease is suggested for a rational diagnostic approach and management.

OBJECTIVE

To report the clinical, biochemical and genetic analysis of three unrelated patients affected by pheochromocytoma.

DESIGN AND PATIENTS

All the coding regions and exon-intron boundaries of RET, VHL, SDHB and SDHD genes were sequenced in three unrelated patients with intra-adrenal pheochromocytoma: a 17-year-old girl, a 15-year-old boy and a 73-year-old man. The family history of all three cases was negative for von Hippel-Lindau lesions or other types of endocrine tumours. Structural modelling of the VHL protein was then performed.

RESULTS

We identified a novel germline VHL gene point mutation, a G to A nucleotide substitution in exon 3, leading to an aspartate to asparagine amino acid change in codon 197 (D197N). No mutations were found in RET, SDHB and SDHD genes. Structural modelling of the VHL protein suggests that the D197N mutation could have a functional role.

CONCLUSIONS

Our study expands the number of VHL gene known mutations and indicates the usefulness of performing the genetic analysis in all patients with apparently sporadic pheochromocytoma.

[Genetics of paragangliomas and pheochromocytomas]

Pheochromocytomas and paragangliomas are rare tumors that arise from chromaffin tissues of the adrenal medulla and from sympathetic and parasympathetic ganglia. Ten susceptibility genes (VHL, RET, NF1, SDHA, B, C and D, SDHAF2, TMEM127 and finally MAX) are responsible for at least 30% of the cases. These patients can either have a familial history of the disease, a syndromic presentation, but can also emerge as apparently sporadic forms. Moreover, recent transcriptomic studies have led to the identification of somatic mutations in VHL and RET genes in 15% of sporadic cases, thus bringing a molecular explanation for nearly half of all cases. These findings have had a major impact on the understanding of the molecular mechanisms of tumorigenesis in pheochromocytomas and paragangliomas. It was shown that the genetic status of tumors is associated with particular transcription signatures, such as the activation of the pseudohypoxic response or the activation of MAPK or mTOR signalling. From nowadays to a close future, these advances will have important consequences on the monitoring of patients, from genetic counseling to a personalized clinical management.

Management of von Hippel-Lindau disease-associated CNS lesions

Patients with von Hippel-Lindau disease (VHL) often harbor significant disease burden within the CNS, specifically craniospinal-axis hemangioblastomas and endolymphatic sac tumors (ELSTs). The majority (60-80%) of patients with VHL harbor hemangioblastomas, and 10-15% will develop ELSTs. Advances in the understanding of the natural history and outcomes associated with the surgical management of VHL-associated tumors have led to improved management of patients with VHL. Optimizing indications for surgical intervention and refining of surgical techniques for these lesions can reduce patient morbidity associated with the management of this syndrome. In this article, we review the various aspects of perioperative management of patients with VHL, surgical indications and general operative principles for the management of hemangioblastomas and ELSTs, and outcomes associated with the surgical treatment of these tumors.

Comparison of 6-18F-fluoro-L-DOPA, 18F-2-deoxy-D-glucose, CT, and MRI in patients with pancreatic neuroendocrine neoplasms with von Hippel-Lindau disease

INTRODUCTION

There are limited data on the utility of 6-(18)F-fluoro-l-3,4-dihydroxyphenylalanine ((18)F-DOPA) and (18)F-2-deoxy-d-glucose ((18)F-FDG) in the workup of patients with pancreatic neuroendocrine tumors (PNETs). The aim of our study was to determine the accuracy of (18)F-DOPA and (18)F-FDG to detect PNETs in patients with von Hippel-Lindau disease (vHL).

METHODS

We studied prospectively 69 patients with a diagnosis of vHL and pancreatic lesion(s) using computed tomography (CT), magnetic resonance imaging (MRI), (18)F-FDG, and (18)F-DOPA. Clinical, genetic, and laboratory characteristics were analyzed to determine association with imaging study results.

RESULTS

In sum, 40 patients underwent evaluation by all 4 modalities; 98 PNETs and 55 PNETs were identified on CT and MRI, respectively. Only 11 of the 98 lesions (11%) were positive on (18)F-DOPA and 45 of the 98 (46%) lesions were positive on (18)F-FDG. There were 13 (18)F-DOPA and 26 (18)F-FDG avid extrapancreatic lesions. One patient underwent resection of an (18)F-DOPA avid extrapancreatic lesion in the lung, with pathology demonstrating a NET. There was no association between (18)F-DOPA and (18)F-FDG avidity and tumor size, age, gender, vHL mutation, or serum chromogranin A level.

CONCLUSION

(18)F-FDG and MRI may be adjuncts to CT in identifying PNETs and metastatic disease. (18)F-DOPA has limited value in identifying PNETs in patients with vHL, but may be useful for identifying extrapancreatic NET lesions.