von Hippel-Lindau disease: genetic, clinical, and imaging features

Third window lesions of the inner ear: A pictorial review

PURPOSE

Radiographic review of pathologies that associate with third window syndrome.

METHODS

Case series and literature review.

RESULTS

Eight unique third window conditions are described and illustrated, including superior, lateral, and posterior semicircular canal dehiscence; carotid-cochlear, facial-cochlear, and internal auditory canal-cochlear dehiscence, labyrinthine erosion from endolymphatic sac tumor, and enlarged vestibular aqueduct.

CONCLUSION

The present study highlights the characteristic imaging features and symptoms to differentiate third window pathologies for expedient diagnosis and management planning.

A Convolutional Neural Network Model for Distinguishing Hemangioblastomas From Other Cerebellar-and-Brainstem Tumors Using Contrast-Enhanced MRI

BACKGROUND

Hemangioblastoma (HB) is a highly vascularized tumor most commonly occurring in the posterior cranial fossa, requiring accurate preoperative diagnosis to avoid accidental intraoperative hemorrhage and even death.

PURPOSE

To accurately distinguish HBs from other cerebellar-and-brainstem tumors using a convolutional neural network model based on a contrast-enhanced brain MRI dataset.

STUDY TYPE

Retrospective.

POPULATION

Four hundred five patients (182 = HBs; 223 = other cerebellar-and brainstem tumors): 305 cases for model training, and 100 for evaluation.

FIELD STRENGTH/SEQUENCE

3 T/contrast-enhanced T1-weighted imaging (T1WI + C).

ASSESSMENT

A CNN-based 2D classification network was trained by using sliced data along the z-axis. To improve the performance of the network, we introduced demographic information, various data-augmentation methods and an auxiliary task to segment tumor region. Then, this method was compared with the evaluations performed by experienced and intermediate-level neuroradiologists, and the heatmap of deep feature, which indicates the contribution of each pixel to model prediction, was visualized by Grad-CAM for analyzing the misclassified cases.

STATISTICAL TESTS

The Pearson chi-square test and an independent t-test were used to test for distribution difference in age and sex. And the independent t-test was exploited to evaluate the performance between experts and our proposed method. P value <0.05 was considered significant.

RESULTS

The trained network showed a higher accuracy for identifying HBs (accuracy = 0.902 ± 0.031, F1 = 0.891 ± 0.035, AUC = 0.926 ± 0.040) than experienced (accuracy = 0.887 ± 0.013, F1 = 0.868 ± 0.011, AUC = 0.881 ± 0.008) and intermediate-level (accuracy = 0.827 ± 0.037, F1 = 0.768 ± 0.068, AUC = 0.810 ± 0.047) neuroradiologists. The recall values were 0.910 ± 0.050, 0.659 ± 0.084, and 0.828 ± 0.019 for the trained network, intermediate and experienced neuroradiologists, respectively. Additional ablation experiments verified the utility of the introduced demographic information, data augmentation, and the auxiliary-segmentation task.

DATA CONCLUSION

Our proposed method can successfully distinguish HBs from other cerebellar-and-brainstem tumors and showed diagnostic efficiency comparable to that of experienced neuroradiologists.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Guidelines for surveillance of patients with von Hippel-Lindau disease: Consensus statement of the International VHL Surveillance Guidelines Consortium and VHL Alliance

Von Hippel‐Lindau disease is a rare inherited cancer‐predisposition syndrome. The authors report the updated recommendations for the multiorgan surveillance protocols.

Diseases of Hereditary Renal Cell Cancers

Germline mutations in tumor suppressor genes and oncogenes lead to hereditary renal cell carcinoma (HRCC) diseases, characterized by a high risk of RCC and extrarenal manifestations. Patients of young age, those with a family history of RCC, and/or those with a personal and family history of HRCC-related extrarenal manifestations should be referred for germline testing. Identification of a germline mutation will allow for testing of family members at risk, as well as personalized surveillance programs to detect the early onset of HRCC-related lesions. The latter allows for more targeted and therefore more effective therapy and better preservation of renal parenchyma.

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.

Downstream Targets of VHL/HIF-α Signaling in Renal Clear Cell Carcinoma Progression: Mechanisms and Therapeutic Relevance

The clear cell variant of renal cell carcinoma (ccRCC) is the most common renal epithelial malignancy and responsible for most of the deaths from kidney cancer. Patients carrying inactivating mutations in the Von Hippel-Lindau (VHL) gene have an increased proclivity to develop several types of tumors including ccRCC. Normally, the Hypoxia Inducible Factor alpha (HIF-α) subunits of the HIF heterodimeric transcription factor complex are regulated by oxygen-dependent prolyl-hydroxylation, VHL-mediated ubiquitination and proteasomal degradation. Loss of pVHL function results in elevated levels of HIF-α due to increased stability, leading to RCC progression. While HIF-1α acts as a tumor suppressor, HIF-2α promotes oncogenic potential by driving tumor progression and metastasis through activation of hypoxia-sensitive signaling pathways and overexpression of HIF-2α target genes. One strategy to suppress ccRCC aggressiveness is directed at inhibition of HIF-2α and the associated molecular pathways leading to cell proliferation, angiogenesis, and metastasis. Indeed, clinical and pre-clinical data demonstrated the effectiveness of HIF-2α targeted therapy in attenuating ccRCC progression. This review focuses on the signaling pathways and the involved genes (cyclin D, c-Myc, VEGF-a, EGFR, TGF-α, GLUT-1) that confer oncogenic potential downstream of the VHL-HIF-2α signaling axis in ccRCC. Discussed as well are current treatment options (including receptor tyrosine kinase inhibitors such as sunitinib), the medical challenges (high prevalence of metastasis at the time of diagnosis, refractory nature of advanced disease to current treatment options), scientific challenges and future directions.

Large scale genotype- and phenotype-driven machine learning in Von Hippel-Lindau disease

Von Hippel-Lindau (VHL) disease is a hereditary cancer syndrome where individuals are predisposed to tumor development in the brain, adrenal gland, kidney, and other organs. It is caused by pathogenic variants in the VHL tumor suppressor gene. Standardized disease information has been difficult to collect due to the rarity and diversity of VHL patients. Over 4100 unique articles published until October 2019 were screened for germline genotype-phenotype data. Patient data were translated into standardized descriptions using Human Genome Variation Society gene variant nomenclature and Human Phenotype Ontology terms and has been manually curated into an open-access knowledgebase called Clinical Interpretation of Variants in Cancer. In total, 634 unique VHL variants, 2882 patients, and 1991 families from 427 papers were captured. We identified relationship trends between phenotype and genotype data using classic statistical methods and spectral clustering unsupervised learning. Our analyses reveal earlier onset of pheochromocytoma/paraganglioma and retinal angiomas, phenotype co-occurrences and genotype-phenotype correlations including hotspots. It confirms existing VHL associations and can be used to identify new patterns and associations in VHL disease. Our database serves as an aggregate knowledge translation tool to facilitate sharing information about the pathogenicity of VHL variants.

Differential VHL mutation patterns in bilateral clear cell RCC distinguishes between independent primary tumors and contralateral metastatic disease

OBJECTIVE

To evaluate whether bilateral, multifocal clear cell renal cell carcinoma (ccRCC) patients can be differentiated by VHL mutation analysis into cases that represent either multiple independently arising primary tumors, or a single primary tumor which has spread ipsilaterally as well as to the contralateral kidney. The nature of kidney cancer multifocality outside of known hereditary syndromes is as yet poorly understood.

MATERIALS AND METHODS

DNA from multiple tumors per patient were evaluated for somatic VHL gene mutation and hypermethylation. A subset of tumors with shared VHL mutations were analyzed with targeted, next-generation sequencing assays.

RESULTS

This cohort contained 5 patients with multiple tumors that demonstrated a shared somatic VHL mutation consistent with metastatic spread including to the contralateral kidney. In several cases this was substantiated by additional shared somatic mutations in ccRCC-associated genes. In contrast, the remaining 14 patients with multiple tumors demonstrated unique, unshared VHL alterations in every analyzed tumor, consistent with independently arising kidney tumors. None of these latter patients showed any evidence of local spread or distant metastasis.

CONCLUSION

The spectrum of VHL alterations within evaluated bilateral, multifocal ccRCC tumors from a single patient can distinguish between multiple independent tumor growth and metastasis. This can be performed using currently available clinical genetic tests and will improve the accuracy of patient diagnosis and prognosis, as well as informing appropriate management.

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

Background

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

Methods

A national audit of VHL disease in the United Kingdom.

Results

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

Conclusions

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

A germline 1;3 translocation disrupting the VHL gene: a novel genetic cause for von Hippel-Lindau

Von Hippel-Lindau (VHL) disease is an autosomal dominant hereditary tumour susceptibility disease caused by germline pathogenic variation of the VHL tumour suppressor gene. Affected individuals are at risk of developing multiple malignant and benign tumours in a number of organs.In this report, a male patient in his 20s who presented to the Urologic Oncology Branch at the National Cancer Institute with a clinical diagnosis of VHL was found to have multiple cerebellar haemangioblastomas, bilateral epididymal cysts, multiple pancreatic cysts, and multiple, bilateral renal tumours and cysts. The patient had no family history of VHL and was negative for germline VHL mutation by standard genetic testing. Further genetic analysis demonstrated a germline balanced translocation between chromosomes 1 and 3, t(1;3)(p36.3;p25) with a breakpoint on chromosome 3 within the second intron of the VHL gene. This created a pathogenic germline alteration in VHL by a novel mechanism that was not detectable by standard genetic testing.Karyotype analysis is not commonly performed in existing genetic screening protocols for patients with VHL. Based on this case, protocols should be updated to include karyotype analysis in patients who are clinically diagnosed with VHL but demonstrate no detectable mutation by existing genetic testing.

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.

Pheochromocytomas and paragangliomas in von Hippel-Lindau disease: not a needle in a haystack

OBJECTIVE

Pheochromocytomas are a hallmark feature of von Hippel-Lindau disease (vHL). To our knowledge, this is the first systematic review with meta-analysis evaluating the frequency of pheochromocytomas and/or paragangliomas (PPGLs) in patients with vHL, as well as among patients with different vHL subtypes.

DESIGN

Systematic review with meta-analysis.

METHODS

We searched on MEDLINE, Scopus, and Web of Science. We included primary studies assessing participants with vHL and reporting on the frequency of PPGL. We performed random-effects meta-analysis to quantitatively assess the frequency of PPGL, followed by meta-regression and subgroup analysis. Risk of bias analysis was performed to assess primary studies' methodological quality.

RESULTS

We included 80 primary studies. In 4263 patients with vHL, the pooled frequency of PPGL was 19.4% (95% CI = 15.9-23.6%, I2 = 86.1%). The frequency increased to 60.0% in patients with vHL type 2 (95% CI = 53.4-66.3%, I2 = 54.6%) and was determined to be of 58.2% in patients with vHL type 2A (95% CI = 49.7-66.3%, I2 = 36.2%), compared to 49.8% in vHL type 2B (95% CI = 39.9-59.7%, I2 = 42.7%), and 84.1% in vHL type 2C (95% CI = 75.1-93.1%, I2 = 0%). In meta-regression analysis, more recent studies were associated with a higher frequency of PPGL. All studies had at least one internal validity item classified as 'high risk of bias,' with 13% studies having low risk of bias in all external validity items.

CONCLUSIONS

PPGLs are a common manifestation of vHL. Despite methodological limitations and differences across primary studies, our results point to the importance of PPGL screening in patients with vHL.

Hemangioblastoma diagnosis and surveillance in von Hippel-Lindau disease: a consensus statement

OBJECTIVE

Hemangioblastomas are a frequent underlying cause of neurological morbidity and death in patients with von Hippel-Lindau disease (VHL). Although these benign tumors can cause significant neurological debility when undetected and untreated, unified evidence-based surveillance recommendations for VHL patients have not been established. To develop consensus recommendations, the VHL Alliance established an expert committee, named the International VHL Surveillance Guidelines Consortium, to define surveillance recommendations.

METHODS

The Central Nervous System (CNS) Hemangioblastoma Subcommittee of the Guidelines Consortium was formed as a multidisciplinary team of experts in the diagnosis and management of hemangioblastomas. Recommendations were formulated using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) and National Comprehensive Cancer Network Categories of Evidence and Consensus categorization after a comprehensive literature review.

RESULTS

Published studies (n = 49) that discussed age at onset, MRI frequency, natural history of VHL, and the risks and benefits of surveillance were analyzed. Based on this analysis, the authors recommend that clinical evaluation (yearly) be used as the primary screening tool for hemangioblastomas in VHL. The subcommittee suggests that screening be performed between the ages of 11 and 65 years, or with the onset of symptoms, for synchronicity with other testing regimens in VHL. The subcommittee also recommends that baseline MRI be first performed at the age of 11 years (suggested 2B, level of evidence D) or after identification of neurological symptoms or signs (if earlier) and continue every 2 years (recommended 2A, level of evidence A).

CONCLUSIONS

The CNS Hemangioblastoma Subcommittee of the International VHL Surveillance Guidelines Consortium here proposes guidelines that aim to increase the early detection of VHL-associated hemangioblastomas to reduce their morbidity and mortality.

C6 Cell Injection into the Optic Nerve of Long-Evans Rats: A Short-Term Model of Optic Pathway Gliomas

The optic pathway glioma (OPG) is a slow-growing brain tumor that arises along the optic nerve or its downstream connections and causing vision to gradually worsen with time. This tumor forms in children with a genetic condition called neurofibromatosis type 1 (NF1), causing tumors to grow on nerves. In normal conditions, glial cells are there to support and protect nerve cells but, in NF1-OPG, glial cells have a genetic defect and grow out of control forming a tumor called a glioma. There are no rat models of NF1-OPG that can be used to explore various treatment options, and mouse models make interventional studies difficult due to their small eye size. We have created a model in which to study the progression of tumor growth in the optic nerve and establish the anatomical and functional consequences of the model and determine its suitability to serve as a surrogate for human disease. C6 rat glioma cells were injected into the optic nerve of Long-Evans rats and allowed to proliferate for 2 weeks. The eye clearly showed proptosis and lens opacity was observed, likely due to increased intraocular pressure caused by growing tumors. Hematoxylin–eosin staining showed marked cellularity, with hyperchromatism and pleomorphism. There was prominent area of necrosis with neoplastic cells palisading around the penumbra. Immunostaining with markers such as S100, β-tubulin III, Foxp3, CD45, Vimentin, and Ki67 confirmed low-grade tumor formation, with a mild immune response. Our results show the utility of a surgically induced rat model of OPG that may be used for exploring various treatment options for NF1 ocular tumors.

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.

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.

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.

Masked malignant phenotype with a benign appearance: beat-up copy number profile may be the key for hemangioblastoma dissemination

Dissemination of histologically benign hemangioblastoma is rare; approximately 30 cases have previously been reported, and all cases occurred several months to years after surgical resection. Herein, we report a case of hemangioblastoma in which leptomeningeal dissemination occurred 2 years after hypofractionated radiation therapy (39 Gy/13 fractions). The tumor was treated primarily with radiation without surgical resection. Biopsy of the disseminated lesion confirmed histological diagnosis as histologically benign hemangioblastoma. Ki67 index was not remarkably elevated for hemangioblastomas. In addition, the methylation class determined by the methylation profiling classifier developed by the German Cancer Research Center (DKFZ)/University Hospital Heidelberg/German Consortium for Translational Cancer Research was consistent with that of common hemangioblastomas. However, genetic analyses showed significant gains and losses throughout the whole genome, indicating that highly aberrant copy number profiles may be the key to elucidating this rare but life-threatening clinical entity. Accumulation of more detailed case reports based on the comparison of specimens obtained before and after surgery or radiation is necessary to better understand the pathophysiology of the dissemination phenotype of hemangioblastoma.

Evaluation, diagnosis and surveillance of renal masses in the setting of VHL disease

This brief report focuses on the evaluation and diagnosis of clinically localized renal masses in children and adults with Von Hippel-Lindau (VHL) disease. Counseling considerations pertinent to the urologists, medical oncologists, and multidisciplinary teams involved in the care of these patients are addressed. As practice patterns regarding the evaluation and management of VHL tumors can vary considerably, this report aims to provide guidance on some of the controversies associated with the diagnostic evaluation and initial management of localized renal masses in VHL patients.

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.

Congenital and hereditary cystic diseases of the abdomen

Congenital and hereditary cystic lesions of the abdomen are relatively rare. Correct diagnosis is critical as they may simulate several other benign and malignant acquired diseases of the abdomen. With the correct and appropriate use of imaging, diagnosis may be relatively straightforward and clinical management may be implemented appropriately. The purpose of this article is to describe imaging findings of common and uncommon congenital and hereditary cystic disease of the abdominal organs.

Update on Hereditary Renal Cancer and Imaging Implications

Up to 8% of renal cancers are thought to have a hereditary component. Several hereditary renal cancer syndromes have been identified over the last few decades. It is important for the radiologist to be aware of findings associated with hereditary renal cancer syndromes to detect tumors early, enroll patients in appropriate surveillance programs, and improve outcomes for the patient and affected family members. This review discusses from a radiologist's perspective well-known hereditary renal cancer syndromes and emerging genetic mutations associated with renal cancer that are less well characterized, focusing on imaging features and known associations.

Clinical response to pazopanib in a patient with endolymphatic sac tumor not associated with von Hippel-Lindau syndrome

Endolymphatic sac tumors (ELSTs) are rare, locally invasive, vascular tumors of the temporal bone. These lesions are associated with von Hippel-Lindau syndrome but may arise sporadically. Early surgical intervention is recommended to prevent permanent neurologic deficits; however, many ELSTs are unresectable or are subtotally resected due to neurovascular compromise. Chemotherapeutic salvage therapy in trials of neoplasms of associated syndromes has targeted angiogenesis with variable response. We present the case of a sporadic ELST, previously minimally responsive to bevacizumab, treated with pazopanib, a multi-kinase inhibitor and antiangiogenic, with good response. Cases such as our patient may demonstrate the utility of novel antiangiogenics in the treatment of these rare neoplasms, particularly when the tumor is unresectable or necessitates subtotal resection.

Von Hippel-Lindau Disease and the Eye

Retinal hemangioblastoma (also referred to as retinal capillary hemangioma) is a benign lesion originating from the endothelial and glial components of the neurosensory retina and optic nerve head. Historically known as a manifestation of the von Hippel-Lindau (VHL) disease, it can be seen as an isolated finding or in association with some rare ocular conditions. In addition to characteristic ophthalmoscopic features, results of numerous ancillary tests including angiography, ultrasound, optical coherence tomography, and genetic tests may support the diagnosis and differentiate it from similar conditions. Because of serious life-threatening complications of VHL disease, every ocular approach to retinal hemangioblastomas should be in relationship with additional multidisciplinary diagnostic and therapeutic efforts. In addition, any patient with actual or probable diagnosis of VHL disease should be screened for ocular involvement. Unfavorable visual loss can occur early, and ocular complications of VHL range from exudative retinopathy to tractional retinal detachment, neovascular glaucoma, and phthisis bulbi. Accordingly, various treatment methods have been tested with overall acceptable responses, including photocoagulation, cryotherapy, photodynamic therapy, plaque radiotherapy, vitrectomy, and more novel intravitreal injections of anti-vascular endothelial growth factors and propranolol.

Von Hippel-Lindau Disease

Phakomatoses (phakoma = birthmark) are a group of diseases or syndromes that have hamartomas (tumorous malformations composed of tissues normally present at the location where they develop) of the skin, brain, and eye (oculoneurocutaneous syndromes).

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

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

Natural history of renal tumours in von Hippel-Lindau disease: a large retrospective study of Chinese patients

Background

Historically, renal cell carcinoma (RCC) is one of the main causes of death in von Hippel-Lindau (VHL) disease. However, the natural history of VHL-related RCC has not been thoroughly elucidated to date. This report described the natural history of VHL-related RCC in a large Chinese VHL cohort and might be helpful in the surveillance and treatment of VHL disease.

Methods

In this retrospective study, we included 196 renal tumours from 150 patients with VHL disease. Statistical analysis was used to evaluate the influence of age of onset, sex, family history, unilateral or bilateral tumour, VHL disease type, mutation type, mutation location, and tumour size on tumour growth, metastasis and survival in patients with VHL disease.

Results

The mean age of onset was 38.8 years, and the mean initial tumour size was 3.1 cm. The mean linear growth rate was 0.49 cm/year. Patients experienced faster tumour growth when they had later age of onset, larger initial tumour size, missense mutation, mutations locating in exon 3, and when they were not affected by cerebral or retinal haemangioblastomas. Tumours larger than 4 cm grew faster than those smaller than 4 cm. Bilateral tumours, large initial tumours, fast tumour growth and metastasis were risk factors for poor prognosis in VHL-related RCC.

Conclusion

This large study demonstrated that age of onset, initial tumour size, concomitant tumours, mutation type and mutation location had an effect on growth rate in VHL-related RCC. Active surveillance may be safe for patients with tumour size less than 4 cm, which is helpful in clinical decision-making.

Disseminated central nervous system hemangioblastoma in a patient with no clinical or genetic evidence of von Hippel-Lindau disease-a case report and literature review

BACKGROUND

Hemangioblastomas (HB) are benign tumors of the central nervous system (CNS) that can appear sporadic or as part of von Hippel-Lindau (VHL) disease. It is often curable with surgical resection, but upon relapse, the disease exhibits a treatment-refractory course.

CASE REPORT

A patient treated for sporadic cerebellar HB relapsed 12 years post-surgery. She developed disseminated disease throughout the CNS, including leptomeningeal manifestations. Repeat surgery and craniospinal radiation therapy were unsuccessful.

CONCLUSION

This case is in line with previous publications on disseminated non-VHL HB. Available treatment options are inefficient, emphasizing the need for improved understanding of HB biology to identify therapeutic targets.

Expression of renal cell markers and detection of 3p loss links endolymphatic sac tumor to renal cell carcinoma and warrants careful evaluation to avoid diagnostic pitfalls

Endolymphatic sac tumor (ELST) is a rare neoplasm arising in the temporal petrous region thought to originate from endolymphatic sac epithelium. It may arise sporadically or in association with Von-Hippel-Lindau syndrome (VHL). The ELST prevalence in VHL ranges from 3 to 16% and may be the initial presentation of the disease. Onset is usually in the 3rd to 5th decade with hearing loss and an indolent course. ELSTs present as locally destructive lesions with characteristic computed tomography imaging features. Histologically, they show papillary, cystic or glandular architectures. Immunohistochemically, they express keratin, EMA, and variably S100 and GFAP. Currently it is recommended that, given its rarity, ELST needs to be differentiated from other entities with similar morphologic patterns, particularly other VHL-associated neoplasms such as metastatic clear cell renal cell carcinoma (ccRCC). Nineteen ELST cases were studied. Immunohistochemistry (18/19) and single nucleotide polymorphism microarray testing was performed (12/19). Comparison with the immunophenotype and copy number profile in RCC is discussed. Patients presented with characteristic bone destructive lesions in the petrous temporal bones. Pathology of tumors showed characteristic ELST morphology with immunoexpression of CK7, GFAP, S100, PAX-8, PAX-2, CA-9 in the tumor cells. Immunostaines for RCC, CD10, CK20, chromogranin A, synaptophysin, TTF-1, thyroglobulin, and transthyretin were negative in the tumor cells. Molecular testing showed loss of 3p and 9q in 66% (8/12) and 58% (7/12) cases, respectively. Immunoreactivity for renal markers in ELST is an important diagnostic caveat and has not been previously reported. In fact, renal markers are currently recommended in order to rule out metastatic RCC although PAX gene complex and CA-9 have been implicated in the development of the inner ear. Importantly copy number assessment of ELST has not been previously reported. Loss of 3p (including the VHL locus) in ELST suggests similar mechanistic origins as ccRCC.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Unilateral Papillary Cystadenoma of the Epididymis as a First Presentation of Von Hippel-Lindau Disease

Association between papillary cystadenoma of the epididymis (PCE) and Von Hippel-Lindau Disease (VHLD) is well known and stronger for bilateral tumors. Unilateral PCE occurs either as a sporadic tumor without evidence of VHLD or in the context of a known diagnosis of VHLD, indeed it has never been reported as the first manifestation of VHLD. In contrast, we report the case of a boy with an apparently isolated, unilateral PCE that resulted to be the first manifestation of an unknown VHLD. Thus, we recommend screening for VHLD in patients with a new diagnosis of unilateral PCE, especially if the patients are young.

VHL Gene Alterations in Italian Patients with Isolated Renal Cell Carcinomas

Clear cell renal cell carcinoma (ccRCC) is the most common malignant neoplasm of the kidney and belongs to the few human tumors known to develop from mutations of the VHL tumor suppressor gene. VHL germline mutations are associated with hereditary ccRCCs in VHL disease. However, somatic VHL gene defects may also occur in sporadic ccRCCs. In this study, we analyzed the frequency and the spectrum of VHL gene alterations in 35 Italian patients with sporadic renal cell carcinoma (RCC). Tumor-specific intragenic VHL pathogenic mutations were detected in 38% (11/29) of the ccRCC patients and 33% (2/6) of the patients with other types of RCC. One novel 18-bp in-tandem duplication and 4 previously unreported nucleotide changes in the VHL gene were described. Microsatellite analysis showed loss of heterozygosity for at least 1 informative marker in 43% (9/21) of the ccRCCs and 50% (3/6) of the non-ccRCCs; 5 of the 13 tumors (38%) harboring VHL gene alterations also had loss of heterozygosity for at least 1 microsatellite marker. Our results confirm that somatic inactivation of the VHL gene may play a pivotal role in the tumorigenesis of sporadic ccRCCs in Italian patients and suggests that mutation analysis of the VHL gene may be helpful for discriminating sporadic, VHL-gene-related ccRCCs from those related to VHL disease.

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.

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

Study Design

Retrospective cohort study.

Purpose

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

Overview of Literature

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

Methods

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

Results

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

Conclusions

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

Sporadic Hemangioblastoma Arising from the Infundibulum

Hemangioblastomas are rare vascular tumors most often found in the posterior fossa and cervical spinal cord and commonly associated with von Hippel-Lindau Disease. We report a case of sporadic hemangioblastoma in a patient without von Hippel-Lindau Disease. Imaging characteristics included a solid, suprasellar mass that was homogeneously enhancing. These findings most resembled a pituicytoma or choroid glioma because of the close association with the infundibulum and the homogeneous avid enhancement. Microscopically, the neoplasm was seen to be composed of vascular channels associated with foamy stromal cells, containing clear cytoplasmic vacuoles. Microscopic and immunohistochemical findings were consistent with hemangioblastoma. Hemangioblastomas are a rare form of vascular tumor most commonly associated with von-Hippel Lindau disease. Our finding of non-cystic hemangioblastoma arising from the infundibulum demonstrates that, while rare, hemangioblastomas should be considered on the differential diagnosis for an avidly enhancing suprasellar mass.

Kidney Tumor in a von Hippel-Lindau (VHL) Patient With Intensely Increased Activity on 68Ga-DOTA-TATE PET/CT

Renal and pancreatic cysts and tumors are the most common visceral manifestations of von Hippel-Lindau (VHL) disease, a heritable multisystem cancer syndrome characterized by development of a variety of malignant and benign tumors. We report a case of a VHL patient with multiple renal cystic and complex cystic/solid lesions. The patient underwent Ga-DOTA-TATE-PET/CT showing intensely increased activity by a solid lesion which demonstrated enhancement on both CT and MRI scans, raising high suspicion for malignancy. The presented case indicates application of SSTR-imaging using Ga-DOTA-conjugated peptides in VHL-patients and emphasizes the need for cautious interpretation of renal parenchyma Ga-DOTATATE activity.