Von Hippel-Lindau Disease: Current Challenges and Future Prospects

Update on Whole-Body MRI Surveillance for Pediatric Cancer Predisposition Syndromes

Whole-body MRI (WBMRI) is an integral part of screening infants, children, and adolescents for presymptomatic neoplasms in certain cancer predisposition syndromes, which include Li-Fraumeni and constitutional mismatch repair deficiency syndromes, among others. The list of syndromes in which WBMRI adds value, as part of a comprehensive surveillance protocol, continues to evolve in response to new evidence, growing experience, and more widespread adoption. In July 2023, the AACR reconvened an international, multidisciplinary panel to revise and update recommendations stemming from the 2016 AACR Special Workshop on Childhood Cancer Predisposition. That initial meeting resulted in a series of publications in Clinical Cancer Research in 2017, including "Pediatric Cancer Predisposition Imaging: Focus on Whole-Body MRI." This 2024 review of WBMRI in cancer predisposition syndrome updates the 2017 WBMRI publication, the revised recommendations derived from the 2023 AACR Childhood Cancer Predisposition Workshop based on available data, societal guidelines, and expert opinion. Different aspects of acquiring and interpreting WBMRI, including diagnostic accuracy, are discussed. The application of WBMRI in resource-poor environments, as well as integration of whole-body imaging techniques with emerging technologies, such as cell-free DNA ("liquid biopsies") and artificial intelligence/machine learning, is also considered.

Innovative solutions? Belzutifan therapy for hemangioblastomas in Von Hippel-Lindau disease: A systematic review and single-arm meta-analysis

BACKGROUND

Von Hippel-Lindau (VHL) disease is a rare autosomal dominant disorder that predisposes patients to develop multiple cysts and tumors, such as hemangioblastomas (HBs) and clear cell renal cell carcinoma (ccRCC), due to mutations in the VHL tumor suppressor gene. While treatment of HBs varies based on their characteristics and has improved patient survival, it still involves high morbidity and mortality, leading to ongoing debates and studies to refine therapy strategies. Recent developments include the emergence of Belzutifan, a novel inhibitor targeting hypoxia-inducible factor 2α (HIF-2α), which has shown promising results in ongoing trials, particularly for patients not immediately requiring surgery.

METHODS

This systematic review and meta-analysis aimed to comprehensively evaluate the efficacy and safety of Belzutifan for treating HBs associated with VHL disease. Search was conducted across Medline, Embase, Cochrane, and Web of Science databases. Statistical Analysis was performed, with proportions and 95 % confidence intervals. Statistical analyses were carried out using R Studio.

RESULTS

Ten studies were selected, comprising 553 patients. The population mean age was 40 (24-65), and 50 % of the population was formed by males. In terms of proportion, 6 analyses were performed: Disease Stability of 31 % [95 %CI:14 %-47 %; I2 = 2 %]; Disease Progression of 2 %[95 %CI:0 %-9 %; I2 = 0 %]; Partial Response of 75 % [95 %CI:54 %-96 %; I2 = 58 %]. Complete response of 1 % [95 %CI:0 %-7 %; I2 = 0 %];and Side effects, anemia 81 % rate [95 % CI:54 %-100 %; I2 = 94 %], and fatigue rate of 79 % [95 % CI:54 %-100 %;I2 = 94 %].

CONCLUSION

Results indicate that Belzutifan effectively stabilizes disease, reduces tumor progression, and achieves significant therapeutic responses, although side effects like anemia and fatigue were noted.

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

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

GENETICS

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

PATHOPHYSIOLOGY

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

CLINICAL MANIFESTATIONS

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

DIAGNOSIS

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

TREATMENT

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

CHALLENGES

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

Von-Hippel Lindau protein amyloid formation. The role of GST-tag

In the last decade, much attention was given to the study of physiological amyloid fibrils. These structures include A-bodies, which are the nucleolar fibrillar formations that appear in the response to acidosis and heat shock, and disassemble after the end of stress. One of the proteins involved in the biogenesis of A-bodies, regardless of the type of stress, is Von-Hippel Lindau protein (VHL). Known also as a tumor suppressor, VHL is capable to form amyloid fibrils both in vitro and in vivo in response to the environment acidification. As with most amyloidogenic proteins fusion with various tags is used to increase the solubility of VHL. Here, we first performed AFM-study of fibrils formed by VHL protein and by VHL fused with GST-tag (GST-VHL) at acidic conditions. It was shown that formed by full-length VHL fibrils are short heterogenic structures with persistent length of 2400 nm and average contour length of 409 nm. GST-tag catalyzes VHL amyloid fibril formation, superimpose chirality, increases length and level of hierarchy, but decreases rigidity of amyloid fibrils. The obtained data indicate that tagging can significantly affect the fibrillogenesis of the target protein.

Expression of somatostatin receptors in hemangioblastomas associated with von Hippel-Lindau disease as a novel diagnostic, therapeutic, and follow-up opportunity: A case report and literature review

Hemangioblastomas associated with von Hippel-Lindau (VHL) disease are frequently multiple and recur during prolonged follow-up. Currently, no systemic treatment is available for these tumors. Recent studies have shown the expression of somatostatin receptors in these types of hemangioblastomas. Notably, increased somatostatin receptor expression in a tumor, as determined by peptide-receptor radionuclide imaging, is a predictive factor of response to treatment with somatostatin analogs and peptide-receptor radionuclide therapy. The aim of this study was to describe the case of a patient with increased expression of somatostatin receptors in a suprasellar hemangioblastoma associated with VHL disease and conduct a literature review on somatostatin receptor expression in patients with VHL-associated hemangioblastomas. We describe herein the case of a 51-year-old man with VHL disease who had a suprasellar hemangioblastoma detected on magnetic resonance imaging. Peptide-receptor radionuclide imaging using gallium-68-DOTATOC (68Ga-DOTATOC) identified increased expression of somatostatin receptors in the suprasellar hemangioblastoma, along with multiple pancreatic neuroendocrine tumors and bilateral pheochromocytomas. The patient was treated for 1 year with lanreotide, a somatostatin analog. A repeat 68Ga-DOTATOC 1 year after starting lanreotide revealed decreased radiotracer uptake by the hemangioblastoma, consistent with a metabolic response. The presence of somatostatin receptors in hemangioblastomas associated with VHL disease is a novel finding. The decreased expression of these receptors after treatment with a somatostatin analog, as described in the present case, positions the somatostatin receptor as a new target for novel diagnostic, therapeutic, and follow-up opportunities in patients with VHL disease.

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.

New Prospects on Neuroimaging in Von Hippel Lindau Disease-A Narrative Review

(1) Background: Hemangiomas in Von Hippel-Lindau (VHL) syndrome patients are typically benign but pose threats due to their vital locations involving the central nervous system and the retina. An MRI is currently recommended as the gold standard for tumors associated with VHL in the head region. This narrative review aims to comprehensively outline current standards and recent findings related to imaging of retinal and CNS hemangiomas in Von Hippel-Lindau syndrome. (2) Material and Methods: A review in adherence to PRISMA guidelines using the search string "Von Hippel-Lindau hemangioblastoma imaging" was conducted on PUBMED and SCOPUS databases. (3) Results: After reviewing 455 titles and abstracts, 20 publications fulfilling the inclusion criteria were analyzed. The analysis included studies describing MRI, CT, optical coherence tomography, and PET/CT. (4) Conclusion: While MRI remains the gold standard for diagnosing head tumors in Von Hippel-Lindau syndrome, various PET/CT methods show promise as alternative imaging modalities.

von Hippel-Lindau disease-related neoplasia with an emphasis on renal manifestations

von Hippel-Lindau (VHL) disease is characterized by biallelic inactivation of the VHL gene leading to abnormal or absent VHL protein function, and constitutive activation of hypoxia-inducible factors (HIF) that leads to pro-tumorigenic signaling. Individuals with VHL disease develop numerous cysts and tumors involving multiple organs including the kidneys, central nervous system, endolymphatic sac, lungs, pancreatobiliary system, adrenal glands, epididymis, and/or broad ligament. On histologic examination, these lesions show morphologic overlap as they are frequently characterized by cells with clear cytoplasm and prominent vascularity. In addition to distinguishing non-renal tumors from metastatic clear cell renal cell carcinoma, understanding site-specific histopathologic and immunophenotypic features of these tumors has several applications. This includes distinguishing VHL-related tumors from those that arise sporadically and lack VHL gene alterations, guiding further genetic workup, and helping distinguish between different genetic predisposition syndromes. In this context, immunohistochemical studies for markers such as paired box 8 (PAX-8), carbonic anhydrase 9 (CA9), and glucose transporter 1 (GLUT-1) have an important role in routine clinical practice and represent cost-effective diagnostic tools. The recent development of targeted therapeutics directed against HIF-mediated signaling represents a significant milestone in the management of VHL disease and highlights the importance of accurately diagnosing and characterizing the wide spectrum of VHL disease-associated lesions.

Early Screening and Identification of an Asymptomatic Pheochromocytoma in a Child with Von Hippel-Lindau: A Case Report

Introduction

Von Hippel-Lindau (VHL) is a diagnosis that leads to increased risk of tumor development over the course of a patient's lifetime. Patients with VHL undergo screening for multiple tumor types, including pheochromocytomas (PCCs). There is variability among the different international guidelines regarding the age to begin PCC screening, with most suggesting 5 years for screening initiation.

Case Presentation

Our patient is a 4-year-old female who underwent screening for PCC at the time of her VHL diagnosis while asymptomatic that identified a unilateral PCC. This was amendable to treatment with laparoscopic partial adrenalectomy.

Conclusion

This is the first report of an asymptomatic PCC being identified in a patient under the age of 5. With early identification, this was treated surgically before it caused systemic symptoms with preservation of normal adrenal gland tissue. This supports adhering to the pediatric specific guidelines which recommend earlier initiation of PCC screening in pediatric patients with VHL.

Case report: Obstructive azoospermia as the first presentation of Von Hippel-Lindau disease

We report the case of a 38-year-old man whose diagnostic workup for primary infertility led to the discovery of obstructive azoospermia due to bilateral papillary cystadenoma of the epididymis (PCE). Given the rarity of this finding and because PCE could be a manifestation of Von Hippel-Lindau disease (VHL), although the patient had no family or personal history of VHL, the VHL gene was tested, and a known pathogenetic variant (c.464-1G>A; p.)? was found. Screening for other Von Hippel-Lindau disease-associated neoplasms revealed bilateral retinal capillary hemangioblastomas, clear cell renal cell carcinoma, and multiple pancreatic cysts. In this case, an accurate diagnostic workup for male infertility allowed the detection of a rare life-threatening syndrome, already presenting with several silent neoplasms. For this reason, this case report may be useful for reproductive medicine specialists in the management of male infertility.

Belzutifan in adults with VHL-associated central nervous system hemangioblastoma: a single-center experience

PURPOSE

Belzutifan is a selective inhibitor of hypoxia-inducible factor 2 alpha (HIF-2a) that has emerged as a targeted therapy option for Von Hippel-Lindau (VHL) syndrome-associated tumors with recent FDA approval. There is limited real-world evidence regarding safety and efficacy in CNS hemangioblastoma. Our objective was to report on our clinical experience with belzutifan in adult patients with VHL-associated CNS hemangioblastoma.

METHODS

We retrospectively reviewed our institutional experience of belzutifan in adult patients (> 18 years of age at time of therapy) with VHL and craniospinal CNS hemangioblastomas not amenable to surgical resection. The period for study review was October 2021 to March 2023.

RESULTS

4 patients (all female) with a median age of 36 years at time of belzutifan initiation were included. Median duration of therapy at last follow-up was 11 months (6-17 months). All patients had radiographic response to therapy after a median of 3 months (2-5 months), with maximal response to therapy after a median of 8 months (3-17 months). Therapy was well tolerated, with the most common adverse effect being anemia. No patients had treatment pauses or dose adjustments due to belzutifan-related toxicity. No patients experienced hypoxia.

CONCLUSION

We showed that belzutifan is safe and well-tolerated with strong disease response for CNS hemangioblastoma in adults with VHL, supporting continued use of belzutifan in this patient population. Future studies should assess duration of treatment, effects of cessation after long-term use, and markers of therapeutic response.

Case Report: Aggressive neural crest tumors in a child with familial von Hippel Lindau syndrome associated with a germline VHL mutation (c.414A>G) and a novel KIF1B gene mutation

Introduction

Von Hippel Lindau (VHL) syndrome is caused by an autosomal dominant hereditary or sporadic germline mutation of the VHL gene with more than five hundred pathogenic mutations identified. Pheochromocytomas and rarely paragangliomas occur in 10-50% of patients with VHL syndrome usually around 30 years of age and exceptionally before the age of 10.

Case presentation

We diagnosed a 9-year-old girl of normal appearance and severe refractory hypertension, with a norepinephrine-secreting pheochromocytoma related to VHL syndrome due to a known familial germline heterozygous mutation of VHL gene (c.414A>G), also present in three members of her family. At age 13, a pelvic tumor and a left adrenal pheochromocytoma that showed to be multi-metastatic to both lungs were discovered in the patient leading to left adrenalectomy and pelvic tumor resection. In addition to the germline VHL gene mutation, blood analysis using Next Generation Sequencing identified a novel heterozygous germline mutation of the KIF1B gene (c.3331_3332del; p.Asn1111Glnfs*21), which is only present in the girl and not the other family members. The patient is currently under steroid substitution therapy and leads a normal life.

Discussion

This family is notable by the early age of onset of multiple neural crest tumors associated with a high propensity for malignancy and metastatic spread. Most reports in the literature associated the VHL mutation with a later onset in adulthood and a benign course, which contrast with our findings and question the role of this mutation in the phenotype expressed in this kindred. Also, the presence of concomitant mutations in two susceptibility genes for neural crest tumors poses the question of their respective roles in the development of tumors in this family. Our familial case description illustrates the potential for systematic use of targeted Next Generation Sequencing with multi-gene panels in patients with neural crest tumors to confirm the role of known susceptibility genes as well as identifying new ones, but also to contribute to comprehensive databases on gene variants and their phenotypic counterparts in this specific area of medicine.

Selective HIF2A Inhibitors in the Management of Clear Cell Renal Cancer and Von Hippel-Lindau-Disease-Associated Tumors

Von Hippel-Lindau (VHL) loss is the hallmark event characterizing the clear cell renal cancer subtype (ccRCC). Carriers of germinal VHL mutations have an increased prevalence of kidney cysts and ccRCC as well as hemangioblastoma, pheochromocytoma and pancreatic neuroendocrine tumors. In both sporadic and inherited ccRCC, the primary mechanism of VHL-mediated carcinogenesis is the abnormal stabilization of hypoxia-inducible factors (HIF1A and HIF2A). While HIF1A acts as a tumor suppressor and is frequently lost through inactivating mutations/14q chromosome deletions, HIF2A acts as an oncogene promoting the expression of its target genes (VEGF, PDGF, CAIX Oct4, among others). Selective HIF2a inhibitors block the heterodimerization between HIF2A and ARNT, stopping HIF2A-induced transcription. Several HIF2A inhibitors have entered clinical trials, where they have shown a favorable toxicity profile, characterized by anemia, fatigue and edema and promising activity in heavily pretreated ccRCC patients. Belzutifan, a second-generation HIF2a inhibitor, was the first to receive FDA approval for the treatment of unresectable ccRCC in VHL syndrome. In this review, we recapitulate the rationale for HIF2a blockade in ccRCC, summarize the development of HIF2a inhibitors from preclinical models up to its introduction to the clinic with emphasis on Belzutifan, and discuss their role in VHL disease management.

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.

Personalized Systemic Therapies in Hereditary Cancer Syndromes

Hereditary cancer syndromes are inherited disorders caused by germline pathogenic variants (PVs) that lead to an increased risk of developing certain types of cancer, frequently at an earlier age than in the rest of the population. The germline PVs promote cancer development, growth and survival, and may represent an ideal target for the personalized treatment of hereditary tumors. PARP inhibitors for the treatment of BRCA and PALB2-associated tumors, immune checkpoint inhibitors for tumors associated with the Lynch Syndrome, HIF-2α inhibitor in the VHL-related cancers and, finally, selective RET inhibitors for the treatment of MEN2-associated medullary thyroid cancer are the most successful examples of how a germline PVs can be exploited to develop effective personalized therapies and improve the outcome of these patients. The present review aims to describe and discuss the personalized systemic therapies for inherited cancer syndromes that have been developed and investigated in clinical trials in recent decades.

Behavioral Improvements following Lesion Resection for Pediatric Epilepsy: Pediatric Psychosurgery?

INTRODUCTION

Resection of brain lesions associated with refractory epilepsy to achieve seizure control is well accepted. However, concurrent behavioral effects of these lesions such as changes in mood, personality, and cognition and the effects of surgery on behavior have not been well characterized. We describe 5 such children with epileptogenic lesions and significant behavioral abnormalities which improved after surgery.

CASE DESCRIPTIONS

Five children (ages 3-14 years) with major behavioral abnormalities and lesional epilepsy were identified and treated at our center. Behavioral problems included academic impairment, impulsivity, self-injurious behavior, and decreased social interaction with diagnoses of ADHD, oppositional defiant disorder, and autism. Pre-operative neuropsychiatric testing was performed in 4/5 patients and revealed low-average cognitive and intellectual abilities for their age, attentional difficulties, and poor memory. Lesions were located in the temporal (2 gangliogliomas, 1 JPA, 1 cavernoma) and parietal (1 DNET) lobes. Gross total resection was achieved in all cases. At mean 1-year follow-up, seizure freedom (Engel 1a in 3 patients, Engel 1c in 2 patients) and significant behavioral improvements (academic performance, attention, socialization, and aggression) were achieved in all. Two patients manifested violence pre-operatively; one had extreme behavior with violence toward teachers and peers despite low seizure burden. Since surgery, his behavior has normalized.

CONCLUSION

We identified 5 patients with severe behavioral disorders in the setting of lesional epilepsy, all of whom demonstrated improvement after surgery. The degree of behavioral abnormality was disproportionate to epilepsy severity, suggesting a more complicated mechanism by which lesional epilepsy impacts behavior. We propose a novel paradigm in which lesionectomy may offer behavioral benefit even when seizures are not refractory. Thus, behavioral improvement may be an important novel goal for neurosurgical resection in children with epileptic brain lesions.

Síndrome de von Hippel-Lindau em um Serviço Privado de Câncer em São Paulo: Relato de Caso

Introdução: A síndrome de von Hippel-Lindau (VHL) é uma patologia hereditária autossômica dominante que envolve o crescimento de tumores em diversas regiões do corpo humano em razão da mutação no gene VHL. Relato do caso: Paciente, sexo masculino, 38 anos, há três anos queixava-se de cefaleia recorrente, com piora progressiva. Foi diagnosticado com uma lesão em cerebelo cuja ressonância magnética cerebral encontrou uma formação expansiva na porção posteroinferior do hemisfério cerebelar esquerdo. Foi realizada tomografia multislice de abdome, que evidenciou formação nodular esplênica com realce marginal. A imagem da coluna cervical demonstrou pequeno nódulo localizado na medula cervical (intramedular) adjacente à vértebra cervical 3 (C3). Diante dos achados, o paciente foi submetido à ressecção macroscópica total da lesão do cerebelo, com laudo anatomopatológico de hemangioblastoma cerebelar grau 1, de acordo com a classificação da Organização Mundial da Saúde (OMS), que é um tumor benigno com baixa agressividade e recorrência. O teste imuno-histoquímico mostrou cluster of differentiation 34 (CD 34) positivo, índice de proliferação celular (Ki67) positivo (<5%), alfa inibina positiva e epithelial membrane antigen (EMA) negativo. Como o paciente não tinha história familiar de câncer, em função dos achados radiológicos, foi realizado sequenciamento de nova geração identificando a variante patogênica VHL c.292T>C, constatado em linhagem germinativa que, apesar do desconhecimento de história familiar positiva para a síndrome, confirmou o diagnóstico do paciente. Conclusão: O conjunto de achados clínicos e a variante no gene VHL confirmam o diagnóstico da síndrome.

Automatic segmentation of clear cell renal cell tumors, kidney, and cysts in patients with von Hippel-Lindau syndrome using U-net architecture on magnetic resonance images

We demonstrate automated segmentation of clear cell renal cell carcinomas (ccRCC), cysts, and surrounding normal kidney parenchyma in patients with von Hippel-Lindau (VHL) syndrome using convolutional neural networks (CNN) on Magnetic Resonance Imaging (MRI). We queried 115 VHL patients and 117 scans (3 patients have two separate scans) with 504 ccRCCs and 1171 cysts from 2015 to 2021. Lesions were manually segmented on T1 excretory phase, co-registered on all contrast-enhanced T1 sequences and used to train 2D and 3D U-Net. The U-Net performance was evaluated on 10 randomized splits of the cohort. The models were evaluated using the dice similarity coefficient (DSC). Our 2D U-Net achieved an average ccRCC lesion detection Area under the curve (AUC) of 0.88 and DSC scores of 0.78, 0.40, and 0.46 for segmentation of the kidney, cysts, and tumors, respectively. Our 3D U-Net achieved an average ccRCC lesion detection AUC of 0.79 and DSC scores of 0.67, 0.32, and 0.34 for kidney, cysts, and tumors, respectively. We demonstrated good detection and moderate segmentation results using U-Net for ccRCC on MRI. Automatic detection and segmentation of normal renal parenchyma, cysts, and masses may assist radiologists in quantifying the burden of disease in patients with VHL.

[Stereotactic irradiation for optic nerve hemangioblastoma associated with Von Hippel-Lindau disease: a case report and literature review]

Hemangioblastoma is a benign tumor of the central nervous system arising sporadically or as a component of Von Hippel-Lindau disease. Von Hippel-Lindau disease is a rare autosomal dominant hereditary syndrome with various phenotypes caused by VHL gene variants. To date, only about 40 cases of optic nerve hemangioblastoma have been described in the literature. Stereotactic irradiation may be effective for supratentorial hemangioblastomas including lesions of optic nerves. The authors describe a rare case of stereotactic irradiation of intraorbital hemangioblastoma of the optic nerve in a patient with Von Hippel-Lindau disease.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Immunotherapy for Pediatric Brain and Spine Tumors: Current State and Future Directions

BACKGROUND

Brain tumors are the most common solid tumors and the leading cause of cancer-related deaths in children. Incidence in the USA has been on the rise for the last 2 decades. While therapeutic advances in diagnosis and treatment have improved survival and quality of life in many children, prognosis remains poor and current treatments have significant long-term sequelae.

SUMMARY

There is a substantial need for the development of new therapeutic approaches, and since the introduction of immunotherapy by immune checkpoint inhibitors, there has been an exponential increase in clinical trials to adopt these and other immunotherapy approaches in children with brain tumors. In this review, we summarize the current immunotherapy landscape for various pediatric brain tumor types including choroid plexus tumors, embryonal tumors (medulloblastoma, AT/RT, PNETs), ependymoma, germ cell tumors, gliomas, glioneuronal and neuronal tumors, and mesenchymal tumors. We discuss the latest clinical trials and noteworthy preclinical studies to treat these pediatric brain tumors using checkpoint inhibitors, cellular therapies (CAR-T, NK, T cell), oncolytic virotherapy, radioimmunotherapy, tumor vaccines, immunomodulators, and other targeted therapies.

KEY MESSAGES

The current landscape for immunotherapy in pediatric brain tumors is still emerging, but results in certain tumors have been promising. In the age of targeted therapy, genetic tumor profiling, and many ongoing clinical trials, immunotherapy will likely become an increasingly effective tool in the neuro-oncologist armamentarium.

Intra-arterial Bevacizumab for Posterior Fossa Hemangioblastoma

Hemangioblastoma (HB) is a rare, highly vascularized, and benign central nervous system (CNS) tumor. This vascularity is due to a high degree of signaling by vascular endothelial growth factor (VEGF). Consequently, anti-VEGF agents, such as bevacizumab, have been postulated and shown in a few cases to be effective in treating these tumors when surgical therapy is not feasible. Additionally, selective intra-arterial (IA) administration of bevacizumab has shown promise in treating other cancers such as glioblastoma (GBM). Here, we present the case of a 60-year-old female with a symptomatic posterior fossa HB where embolization and surgery were not feasible due to tumor location. She underwent selective IA treatment with bevacizumab, which led to tumor stability and symptomatic improvement. Bevacizumab has been used intravenously (IV) as a treatment for HB, however, its efficacy has not been well-established. This case demonstrates the potential viability of selective bevacizumab in HB, as demonstrated by symptomatic improvement and decreased tumor size on MRI. Further research is needed to demonstrate the specific efficacy of IA bevacizumab for CNS HB when surgery or other treatment modalities are not viable options.

Concurrent intraventricular intracranial myxoid mesenchymal tumor and ependymoma in a long-term Ewing sarcoma survivor

Intracranial myxoid mesenchymal tumor, FET::CREB fusion positive is a rare, recently described central nervous system neoplasm. It is characterized by EWSR1::CREB family transcription factor fusion, typically arises in children and adolescents, and is locally aggressive even after gross total resection. Currently, there are little data available to guide management and gauge long-term prognosis. Furthermore, there have been no reports of these lesions occurring simultaneously with other intracranial neoplasms or in patients with a history of malignancy. Here we describe the first case of a very unusual patient with intracranial myxoid mesenchymal tumor of the right lateral ventricle with a concurrent fourth ventricular ependymoma who had a remote history of Ewing sarcoma of the right fibula.

Characterization of Microscopic Multicellular Foci in Grossly Normal Renal Parenchyma of Von Hippel-Lindau Kidney

Background and Objectives: This study aims to describe the earliest renal lesions in patients with von Hippel-Lindau (VHL) disease, especially the multicellular microscopic pathologic events, to get information into the genesis of renal neoplasms in this condition. Materials and Methods: Multicellular events were identified, and 3dimensional reconstruction was performed in grossly normal kidney parenchyma from VHL disease patients by using H&E-stained slides previously prepared. Results: The lesions were measured and the volume of clusters was calculated. Immunohistochemistry was performed for downstream HIF-target protein carbonic anhydrase 9 (CAIX) as well as CD34 for assessment of angiogenesis. We divided lesions into four types according to lesion height/size. The number of lesions was markedly decreased from lesion 1 (smallest) to lesion 2, then from lesions 2 to 3, and again from lesion 3 to 4. Distribution was highly consistent in the four cases, and the same decrement pattern was seen in all blocks studied. The volumes of clusters were measured and divided into three categories according to their volume. The most frequent pathologic event in VHL kidneys was category 1 (smallest volume), then category 2, and then category 3. Conclusion: We demonstrate that tracking histologic and morphologic changes in 3 dimensions of multicellular microscopic pathologic events enabled us to confirm a protracted sequence of events from smaller to larger cellular amplification events in VHL kidney.

Von Hipple-Lindau disease complicated with central retinal vein occlusion: a case report

Background

Central Retinal Vein Occlusion (CRVO) is a rare complication of von Hipple-Lindau (VHL) disease. This report presents the first case of VHL disease complicated with CRVO caused by VHL c.208G > A mutation.

Case presentation

A 20 s man whose left eye visual acuity gradually declined for half a year. The visual acuity of the left eye is counting fingers. Fundus examination revealed that retinal hemangioblastoma was also found in addition to typical CRVO signs such as tortuous expansion of retinal veins and flame-shaped hemorrhage of the retina. Liver tumor, cerebral infarction and erythrocytosis were found during systemic examination, and the diagnosis of polycythemia was confirmed by bone marrow smear. Furthermore, both family history and genetic analysis indicated that the patient had VHL disease caused by VHL c.208G > A. In this patient, a large number of bone marrow erythrocytes proliferated due to VHL disease, which led to the increase of blood viscosity and erythrocyte vascular adhesion, resulting in the obstruction of central retinal vein blood flow, and finally CRVO. For CRVO and its pathogenic factor polycythemia, patient received laser retinal photocoagulation and phlebotomies. After a 1-year follow-up, the vision in the left eye improved to 0.2 logMAR.

Conclusions

This is a rare case of polycythemia complicated by CRVO in patient with VHL disease. It reminds us that the systemic disease factors should be fully considered in the diagnosis of young patients with CRVO, and that treatment requires a coordinated effort of physicians.

Tumorigenesis Mechanisms Found in Hereditary Renal Cell Carcinoma: A Review

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

Retinal hemangioblastoma in a patient with Von Hippel-Lindau disease: A case report and literature review

BACKGROUND

Retinal hemangioblastoma (RH) is a rare benign tumor and a considerable number of which are caused by Von Hippel-Lindau disease (VHL). Herein, we described a case of VHL-associated RH with retinal detachment who underwent both laser photocoagulation and vitreoretinal surgery and received satisfactory visual recovery. In addition, we reviewed the current diagnosis, genotype-phenotype association, and treatment of VHL-associated RH.

CASE DESCRIPTION

A 34-year-old woman presented with vision loss in the right eye at our hospital. Fundus photography and angiography showed retinal detachment and multiple large hemangiomas in the right eye. The visual acuity improved significantly after laser photocoagulation and vitreoretinal surgery. Genetic analyses showed a p.Asn78Ser (c.233A>G) heterozygous missense mutation in the VHL gene.

CONCLUSION

We described a rare case of VHL-associated RH and may provide a new perspective towards diagnosis and treatment of this disease. RH is one of the most common manifestations of VHL and poses a serious threat to vision. Ophthalmic examination methods include fundus examination and fundus photography, etc. The management of the disease emphasizes timely follow-up, early detection of the lesion, and the decision of treatment options according to the size, location and complications of the lesion, including ablation therapy and vitreoretinal surgery. Clinicians should strengthen the understanding of this rare disease for early detection and treatment.

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

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

Intramedullary spinal cord metastasis of clear cell renal carcinoma in a Von Hippel–Lindau patient

Background:

Intramedullary spinal cord metastasis is uncommon and represents only 0.6% of all spinal tumors. Renal cell carcinoma is even less frequent in this group than in lung and breast cancer. Patients with Von Hippel– Lindau disease (VHLd) present spinal hemangioblastoma more frequently.

Case Description:

A 59-year-old female patient presented with medullary syndrome. There was a previous history of VHLd, with a cerebellar hemangioblastoma resection years ago. The radiological investigation showed a cervical intramedullary solid-cystic lesion. The patient has submitted a tumor resection, and a pathological and immunohistochemistry study confirmed clear cell renal carcinoma metastasis.

Conclusion:

In patients with VHLd, the presence of an intramedullary solid-cystic lesion may not represent always a hemangioblastoma. Other diagnostic possibilities must be evaluated, despite being epidemiologically less frequent. Inside the group of patients with VHLd, only a previous case of intramedullary spinal cord renal cell carcinoma was reported in the literature.

VHL syndrome without clear family history: A rare case report and literature review of Chinese patients

Objective

To analyze the clinical manifestations and imaging features of a hospitalized patient with intermittent headache who was finally diagnosed with von Hippel–Lindau (VHL) syndrome and to perform whole-exon gene detection to improve the understanding of the diagnosis and treatment strategies of the disease.

Methods

A case of suspected VHL syndrome in Shanxi Provincial People's Hospital was analyzed. Proband DNA was also extracted for whole exome sequencing and screened for causative mutation sites, which were validated by Sanger sequencing. The literature about VHL gene mutations in Chinese patients in the past 10 years were also reviewed.

Results

There is a heterozygous mutation site c.499C > G on the VHL gene on the short arm of chromosome 3 of the patient, which is a missense mutation. The mutation results in the substitution of arginine with glycine at amino acid 167 of the encoded protein, which may be primarily responsible for the disease in the patient with VHL syndrome. However, the mutation did not occur in other family members.

Conclusion

Early recognition and treatment of VHL syndrome can be available with genetic testing technology. Strengthening the understanding of this complex genetic disease and improving the diagnostic rate of VHL syndrome are helpful for the precise treatment of patients with this disease, which may help prolong the survival time of patients to a certain extent and improve their quality of life.

An MRI-based radiomics model to predict clear cell renal cell carcinoma growth rate classes in patients with von Hippel-Lindau syndrome

PURPOSE

Upfront knowledge of tumor growth rates of clear cell renal cell carcinoma in von Hippel-Lindau syndrome (VHL) patients can allow for a more personalized approach to either surveillance imaging frequency or surgical planning. In this study, we implement a machine learning algorithm utilizing radiomic features of renal tumors identified on baseline magnetic resonance imaging (MRI) in VHL patients to predict the volumetric growth rate category of these tumors.

MATERIALS AND METHODS

A total of 73 VHL patients with 173 pathologically confirmed Clear Cell Renal Cell Carcinoma (ccRCCs) underwent MRI at least at two different time points between 2015 and 2021. Each tumor was manually segmented in excretory phase contrast T1 weighed MRI and co-registered on pre-contrast, corticomedullary and nephrographic phases. Radiomic features and volumetric data from each tumor were extracted using the PyRadiomics library in Python (4544 total features). Tumor doubling time (DT) was calculated and patients were divided into two groups: DT <  = 1 year and DT > 1 year. Random forest classifier (RFC) was used to predict the DT category. To measure prediction performance, the cohort was randomly divided into 100 training and test sets (80% and 20%). Model performance was evaluated using area under curve of receiver operating characteristic curve (AUC-ROC), as well as accuracy, F1, precision and recall, reported as percentages with 95% confidence intervals (CIs).

RESULTS

The average age of patients was 47.2 ± 10.3 years. Mean interval between MRIs for each patient was 1.3 years. Tumors included in this study were categorized into 155 Grade 2; 16 Grade 3; and 2 Grade 4. Mean accuracy of RFC model was 79.0% [67.4-90.6] and mean AUC-ROC of 0.795 [0.608-0.988]. The accuracy for predicting DT classes was not different among the MRI sequences (P-value = 0.56).

CONCLUSION

Here we demonstrate the utility of machine learning in accurately predicting the renal tumor growth rate category of VHL patients based on radiomic features extracted from different T1-weighted pre- and post-contrast MRI sequences.

The hypoxia-driven crosstalk between tumor and tumor-associated macrophages: mechanisms and clinical treatment strategies

Given that hypoxia is a persistent physiological feature of many different solid tumors and a key driver for cancer malignancy, it is thought to be a major target in cancer treatment recently. Tumor-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment (TME), which have a large impact on tumor development and immunotherapy. TAMs massively accumulate within hypoxic tumor regions. TAMs and hypoxia represent a deadly combination because hypoxia has been suggested to induce a pro-tumorigenic macrophage phenotype. Hypoxia not only directly affects macrophage polarization, but it also has an indirect effect by altering the communication between tumor cells and macrophages. For example, hypoxia can influence the expression of chemokines and exosomes, both of which have profound impacts on the recipient cells. Recently, it has been demonstrated that the intricate interaction between cancer cells and TAMs in the hypoxic TME is relevant to poor prognosis and increased tumor malignancy. However, there are no comprehensive literature reviews on the molecular mechanisms underlying the hypoxia-mediated communication between tumor cells and TAMs. Therefore, this review has the aim to collect all recently available data on this topic and provide insights for developing novel therapeutic strategies for reducing the effects of hypoxia.

Imaging manifestations of von Hippel-Lindau disease: an illustrated guide focusing on abdominal manifestations

Von Hippel-Lindau (VHL) disease is a monogenic autosomal dominant disorder with germline mutations of the VHL anti-oncogene on the short arm of chromosome 3 (3p25-26). It affects 1:36,000-50,000 individuals, with a penetrance greater than 90% at 65 years of age. Although of variable onset and presentation, with pleiotropism even among members of the same family who share a specific mutation, VHL disease usually manifests initially in young adults. It predisposes to the development of benign and malignant tumors of the central nervous system (CNS) and visceral organs. The clinical diagnosis of VHL disease can be made in the following circumstances: a) in patients with a family history of the disease and at least one of the tumors characteristic of it (e.g., retinal or CNS hemangioblastomas, clear cell renal cell carcinoma, pancreatic neuroendocrine tumors, and endolymphatic sac tumors); b) in patients with two or more CNS hemangioblastomas; c) or in patients with a retinal or CNS hemangioblastoma plus at least one visceral tumor characteristic of the disease, excluding renal and epididymal cysts. Imaging plays an important role in the diagnosis and follow-up of patients with VHL disease. This pictorial essay presents characteristic images of abdominal manifestations of VHL disease-related tumors that all radiologists should be aware of.

Manifestações de imagem da doença de von Hippel-Lindau: um guia ilustrado das manifestações abdominais

Resumo A doença de von Hippel-Lindau (VHL) é uma desordem autossômica dominante monogênica com mutações na linha germinativa do antioncogene VHL, no braço curto do cromossomo três (3p25-26). Afeta 1:36.000-50.000 indivíduos, com penetrância superior a 90% aos 65 anos de idade. Embora tenha início e apresentação variáveis, com pleiotropismo mesmo entre membros da mesma família que partilham uma mutação específica, usualmente manifesta-se de início em adultos jovens e predispõe ao desenvolvimento de tumores benignos e malignos no sistema nervoso central (SNC) e órgãos viscerais. Clinicamente, o diagnóstico pode ser realizado em uma das seguintes circunstâncias: a) em pacientes com história familiar de doença de VHL e pelo menos um dos tumores característicos relacionados à síndrome (como hemangioblastomas retinianos ou do SNC, carcinoma de células renais de células claras, tumores neuroendócrinos pancreáticos e tumores do saco endolinfático); b) dois ou mais hemangioblastomas do SNC; c) um hemangioblastoma retiniano ou do SNC mais pelo menos um tumor característico visceral relacionado à síndrome, excluindo-se cistos renais e epididimários. Nesse contexto, a imagem ocupa importante papel no diagnóstico e acompanhamento desses pacientes. Este ensaio iconográfico apresenta imagens características de manifestações abdominais de tumores relacionados à doença de VHL que todos os radiologistas devem conhecer.

Aggressive dissemination of central nervous system hemangioblastoma without association with von Hippel–Lindau disease: A case report and literature review

Background:

Hemangioblastomas (HBs) typically present with benign behavior and are most commonly found in the posterior fossa. Multiple central nervous system (CNS) HBs are usually associated with von Hippel–Lindau disease, and leptomeningeal dissemination of sporadic HBs is extremely rare. A review of the literature identified 30 cases of leptomeningeal dissemination of sporadic HBs previously published in the literature.

Case Description:

We report the case of a patient who was diagnosed with multiple CNS HBs with aggressive progression 6 years after resection of a posterior fossa HB. He underwent multiple surgeries and died 4 years after the diagnosis of the first spinal dissemination.

Conclusion:

Dissemination of sporadic HBs is rare and aggressive disease evolution is usually observed. Further studies are necessary to determine the optimal therapeutic options.

Hyper-reflective retinal foci as possible in vivo imaging biomarker of microglia activation in von Hippel-Lindau disease

Purpose

von Hippel-Lindau (VHL) disease is caused by a mutation of the VHL gene and characterized by the development of retinal hemangioblastomas (RH). Current pathophysiologic mechanisms of RH development and progression are still insufficient to predict RH behavior. VHL gene is involved in the cellular response to hypoxia and in many intracellular signaling pathways expressed both in angiogenesis and inflammation. Optical coherence tomography (OCT) allows to identify hyper-reflective retinal foci (HRF) known as aggregates of activated microglial cells as possible in vivo biomarker of local inflammation. The aim of the present study was to investigate the presence of HRF in patients with genetically confirmed VHL disease.

Methods

In this cross-sectional study, patients with VHL underwent complete ophthalmological examination and OCT with HRA + OCT Spectralis. HRF were manually identified and calculated in inner (IR), outer (OR) and full retina. Age-matched healthy subjects were enrolled as controls.

Results

113 eyes of 63 VHL patients and 56 eyes of 28 healthy subjects were evaluated. HRF number was significantly higher in VHL than in controls in IR (28.06 ± 7.50 vs 25.25 ± 6.64, p = 0.042). No difference was observed in OR and in full retina (OR: 7.73 ± 2.59 vs 7.95 ± 2.51, p = 0.599; full retina: 35.79 ± 8.77 vs 33.20 ± 7.47, p = 0.093).

Conclusion

The increase of HRF, which mirror retinal microglial activation, characterizes VHL eyes. The role of activated microglia in the retina of VHL eyes needs to be better investigated, mainly considering local VHL disease manifestations.

Diagnostic Strategies and Algorithms for Investigating Cancer Predisposition Syndromes in Children Presenting with Malignancy

Simple Summary

Here we provide an overview of several genetically determined conditions that predispose to the development of solid and hematologic malignancies in children. Diagnosing these conditions, whose prevalence is estimated around 10% in children with cancer, is useful to warrant personalized oncologic treatment and follow-up, as well as psychological and genetic counseling to these children and their families. We reviewed the most recent studies focusing on the prevalence of cancer predisposition syndromes in cancer-bearing children and the most-used clinical screening tools. Our work highlighted the value of clinical screening tools in the management of young cancer patients, especially in settings where genetic testing is not promptly accessible.

Abstract

In the past recent years, the expanding use of next-generation sequencing has led to the discovery of new cancer predisposition syndromes (CPSs), which are now known to be responsible for up to 10% of childhood cancers. As knowledge in the field is in constant evolution, except for a few “classic” CPSs, there is no consensus about when and how to perform germline genetic diagnostic studies in cancer-bearing children. Several clinical screening tools have been proposed to help identify the patients who carry higher risk, with heterogeneous strategies and results. After introducing the main clinical and molecular features of several CPSs predisposing to solid and hematological malignancies, we compare the available clinical evidence on CPS prevalence in pediatric cancer patients and on the most used decision-support tools in identifying the patients who could benefit from genetic counseling and/or direct genetic testing. This analysis highlighted that a personalized stepwise approach employing clinical screening tools followed by sequencing in high-risk patients might be a reasonable and cost-effective strategy in the care of children with cancer.

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.

Manifestações de imagem da doença de von Hippel-Lindau: um guia ilustrado com foco no sistema nervoso central

Abstract A doença de von Hippel-Lindau (VHL) é uma síndrome hereditária autossômica dominante rara que afeta a linha germinativa do gene VHL, um gene supressor tumoral. A doença de VHL é caracterizada pelo desenvolvimento multissistêmico de uma variedade de tumores benignos e malignos, especialmente no sistema nervoso central (SNC). Dentre eles, destacam-se hemangioblastomas retinianos e do SNC, e o tumor do saco endolinfático. Os diferentes locais dos tumores justificam a diversidade de sinais e sintomas relacionados à doença, que usualmente se manifestam com a idade média de 33 anos. Apesar dos avanços da medicina, a expectativa de vida média desses pacientes é de 49 anos. Exames de imagem têm papel fundamental no diagnóstico e são essenciais no seguimento dos pacientes com doença de VHL. Este ensaio iconográfico descreve as manifestações características dos tumores do SNC relacionados à doença de VHL que todos os residentes de radiologia devem saber.

Imaging manifestations of von Hippel-Lindau disease: an illustrated guide focusing on the central nervous system

Von Hippel-Lindau (VHL) disease is a rare, autosomal dominant inherited syndrome that affects the germline of the VHL gene, a tumor suppressor gene. VHL disease is characterized by the multisystemic development of a variety of benign and malignant tumors, especially in the central nervous system (CNS). Such tumors include retinal and CNS hemangioblastomas, as well as endolymphatic sac tumors. The various tumor sites are responsible for the diversity of signs and symptoms related to the disease. The mean age at symptom onset is 33 years. Despite medical advances, the average life expectancy of patients with VHL disease is 49 years. Imaging plays a pivotal role in the clinical diagnosis and is essential to the follow-up of patients with VHL disease. This pictorial essay describes characteristic CNS manifestations of VHL disease-related tumors that all radiology residents should be aware of.

Lenvatinib as a Therapeutic Option in Unresectable Metastatic Pheochromocytoma and Paragangliomas

Context

Metastatic pheochromocytomas and paragangliomas (mPPGL) are rare vascular neuroendocrine tumors that highly express vascular growth factors. Systemic treatment options in cases of unresectable multi-site disease are limited. Multikinase inhibitors, that inhibit angiogenesis, such as lenvatinib, have proven effective in several other malignancies, and may be a viable option for mPPGL.

Objective

To evaluate the efficacy of lenvatinib as salvage therapy in mPPGLs.

Design

Retrospective analysis of mPPGL patients who received lenvatinib from 2015-2020.

Setting

Tertiary referral center

Patients

Patients ≥ 18 years with mPPGL who were treated with lenvatinib were included.

Intervention

Patients were started on lenvatinib 20 mg daily and dose was adjusted according to tolerance or disease progression.

Results

11 patients were included. Median treatment duration was 14.7 months (95% CI: 2.3-NE). Treatment was discontinued due to disease progression, adverse events, or death. Overall survival at 12 months was 80.8% (95% CI: 42.3-94.9%) but its median was not reached. Median progression free survival was 14.7 months (CI 95%: 1.7-NE). Among the 8 patients with measurable disease, overall response rate was 63% as 5/8 experienced a partial response and 3/8 had stable disease. Worsening hypertension and anemia were the most common adverse events (AE).

Conclusions

Lenvatinib may be a viable treatment option for mPPGL, though at the potential risk of worsening hypertension. Larger, multi-center studies are needed to better characterize treatment efficacy.

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.

Practical Genetics for the Neuroradiologist: Adding Value in Neurogenetic Disease

Genetic discoveries have transformed our understanding of many neurologic diseases. Identification of specific causal pathogenic variants has improved understanding of pathophysiology and enabled replacement of many confusing eponyms and acronyms with more meaningful and clinically relevant genetics-based terminology. In this era of rapid scientific advancement, multidisciplinary collaboration among pediatricians, neurologists, geneticists, radiologists, and other members of the health care team is increasingly important in the care of patients with genetic neurologic diseases. Radiologists familiar with neurogenetic disease add value by (1) recognizing constellations of characteristic imaging findings that are associated with a genetic disease before one is clinically suspected; (2) predicting the most likely genotypes for a given imaging phenotype in clinically suspected genetic disease; and (3) providing detailed and accurate descriptions of the imaging phenotype in challenging cases with unknown or uncertain genotypes. This review aims to increase awareness and understanding of pathogenic variants relating to neurologic disease by (1) briefly reviewing foundational knowledge of chromosomes, inheritance patterns, and mutagenesis; (2) providing concrete examples of and detailed information about specific neurologic diseases resulting from pathogenic variants; and (3) highlighting clinical and imaging features that are of greatest relevance for the radiologist.

The Role of VHL in the Development of von Hippel-Lindau Disease and Erythrocytosis

Von Hippel-Lindau disease (VHL disease or VHL syndrome) is a familial multisystem neoplastic syndrome stemming from germline disease-associated variants of the VHL tumor suppressor gene on chromosome 3. VHL is involved, through the EPO-VHL-HIF signaling axis, in oxygen sensing and adaptive response to hypoxia, as well as in numerous HIF-independent pathways. The diverse roles of VHL confirm its implication in several crucial cellular processes. VHL variations have been associated with the development of VHL disease and erythrocytosis. The association between genotypes and phenotypes still remains ambiguous for the majority of mutations. It appears that there is a distinction between erythrocytosis-causing VHL variations and VHL variations causing VHL disease with tumor development. Understanding the pathogenic effects of VHL variants might better predict the prognosis and optimize management of the patient.

Pheochromocytomas and Abdominal Paragangliomas: A Practical Guidance

Simple Summary

Pheochromocytomas and abdominal paragangliomas (PPGLs) are rare. They can be discovered incidentally by imaging with computed tomography or magnetic resonance imaging and during hormonal surveillance in patients with known genetic variants that are associated with PPGLs. As most PPGLs are functioning, a hormonal work-up evaluating for catecholamine excess is recommended. Classical symptoms, such as tachycardia, hypertension and headache, can be present, but when the PPGL is discovered as an incidentaloma, symptoms may be lacking or be more discrete. PPGLs carry malignant potential, and patients should undergo close surveillance, as recurrence of disease or metastasis may develop. Genetic susceptibility for multifocal disease has gained more attention, and germline variants are commonly detected, thus facilitating detection of hereditary cases and afflicted family members. Any patient with a PPGL should be managed by an expert multidisciplinary team consisting of endocrinologists, radiologists, surgeons, pathologists and clinical geneticists.

Abstract

Pheochromocytomas and abdominal paragangliomas (PPGLs) are rare tumors arising from the adrenal medulla or the sympathetic nervous system. This review presents a practical guidance for clinicians dealing with PPGLs. The incidence of PPGLs has risen. Most cases are detected via imaging and less present with symptoms of catecholamine excess. Most PPGLs secrete catecholamines, with diffuse symptoms. Diagnosis is made by imaging and tests of catecholamines. Localized disease can be cured by surgery. PPGLs are the most heritable of all human tumors, and germline variants are found in approximately 30–50% of cases. Such variants can give information regarding the risk of developing recurrence or metastases as well as the risk of developing other tumors and may identify relatives at risk for disease. All PPGLs harbor malignant potential, and current histological and immunohistochemical algorithms can aid in the identification of indolent vs. aggressive tumors. While most patients with metastatic PPGL have slowly progressive disease, a proportion of patients present with an aggressive course, highlighting the need for more effective therapies in these cases. We conclude that PPGLs are rare but increasing in incidence and management should be guided by a multidisciplinary team.

Combination therapies in clinical trials for renal cell carcinoma: how could they impact future treatments?

INTRODUCTION

Pharmacological combinations using immune checkpoint inhibition (ICI), tyrosine kinase inhibition (TKIs), and mammalian target of rapamycin inhibitors (mTOR) have improved survival in metastatic clear cell renal cell cancer (mccRCC). Despite improvements in survival, complete durable responses are rare.

AREAS COVERED

Molecular pathways involved in mccRCC and drugs targets are highlighted. The background and rationale for combination therapy are covered. Results from combination trials are reviewed and potential approaches with biomarker-stratified treatment and novel experimental agents are examined. PubMed Central and ClinicalTrials.gov were searched. Search terms used to identify clinical trials were '(metastatic renal cell cancer OR renal cell carcinoma OR mccRCC OR mRCC OR RCC OR kidney cancer) AND (combination OR combined).'

EXPERT OPINION

First-line standard of care has moved to combination therapy with ICI-ICI and TKI-ICI combinations; VEGF-mTORi is available in subsequent lines. Combining targeted treatments without validated biomarkers is imprecise, and combinations may lead to overtreatment of a subset of patients, exposing them to unnecessary toxicity. The aim of combinations must be clear: improvement in overall survival (OS) and complete response (CR). Recent data suggest a role for novel biomarker stratification rather traditional risk groups. Further combination approaches with triplets and quadruplets should be biomarker directed.

The role of redox homeostasis biomarkers in clear cell renal cell carcinoma development and progression

The clear cell renal cell carcinoma (ccRCC) is the most frequent and the most aggresive subtype of renal cell carcinoma usually detected at an already advanced stage. It might even be observed as a metabolic disease since complex molecular changes and disturbed redox homeostasis are its hallmark. As certain changes are characteristic for tumorigenesis, while some other for metastatic disease, the identification of metabolic modifications could also point out the stage of tumor progression. Hypoxia inducible factor, as a factor regulating transcription of genes encoding glycolytic enzymes, as well as controlling lipid accumulation, has a particular place in ccRCC development. Additionaly, disturbed redox homeostasis induces the Keap1/Nrf2 pathway which further modulates the synthesis of phase-II detoxifying metabolism enzymes. The upregulation of glutathione transferases, Pi class especially, inhibits kinase-dependent apoptosis that is essential in tumor progression. Furthermore, hydrogen peroxide (H2O2) acts as a signaling molecule conveying redox signals, while superoxide dismutase, as well as glutathione peroxidase are enzymes involved in its production and degradation. Hence, the activity of these enzymes impacts hydrogen peroxide levels and consequentially the ability of ccRCC cells to evade negative effect of reactive oxygen species.

Retinal Glial Cells in Von Hippel-Lindau Disease: A Novel Approach in the Pathophysiology of Retinal Hemangioblastoma

Simple Summary

The in vivo optical coherence tomography analysis of the biomarkers of retinal microglia and macroglia in Von Hippel–Lindau disease represents an innovative field of research. The different behavior of these glial cells in Von Hippel–Lindau patients provides new data regarding the pathophysiology of retinal hemangioblastoma, the most common ocular manifestation of this hereditary disorder. Moreover, these biomarkers show a different behavior in Von Hippel–Lindau patients in relation to the presence or absence of retinal hemangioblastoma. Therefore, we can hypothesize that retinal hemangioblastoma is mainly due to the activation of macroglia by previously activated microglial cells.

Abstract

Background: Von Hippel–Lindau (VHL) disease is a neoplastic syndrome caused by a mutation of the VHL tumor suppressor gene. Retinal hemangioblastoma (RH) is a vascularized tumor and represents the most common ocular manifestation of this disease. At the retinal level, VHL protein is able to regulate tumor growth, angiogenic factors, and neuroinflammation, probably stimulating retinal glial cells. The aim of the present study was to analyze in vivo the optical coherence tomography (OCT) biomarkers of retinal macroglia and microglia in a cohort of VHL patients. Methods: The mean thicknesses of macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), and peripapillary retinal nerve fiber layer (pRNFL) were measured with OCT as biomarkers of retinal macroglia. OCT images were also analyzed to detect and quantify hyperreflective retinal foci (HRF), a biomarker of retinal activated microglia. Results: 61 eyes of 61 VHL patients (22 eyes (36.07%) with peripheral RH and 39 eyes (63.93%) without RH) and 28 eyes of 28 controls were evaluated. pRNFL was thinner in VHL patients (p < 0.05) and in VHL without RH (p < 0.01) compared to controls, and thicker in VHL patients with RH than in those without RH (p < 0.05). The thickness of mRNFL (p < 0.0001) and GCL (p < 0.05) was reduced in VHL patients and in VHL without RH compared to controls, whereas mRNFL (p < 0.0001) and GCL (p < 0.05) were increased in VHL patients with RH compared to those without RH. HRF were significantly higher in number in VHL patients and in VHL without RH, than in controls, and significantly lower (p < 0.05) in the eyes of VHL patients with RH, than in those without RH. Conclusions: The OCT analysis, which detects and allows to quantify the biomarkers of retinal microglia (HRF) and macroglia (pRNFL, mRNFL and GCL), showed a different behavior of these two retinal glial cells populations in VHL patients, related to the presence or absence of peripheral RH. These data allow to hypothesize a novel pathophysiologic pathway of retinal hemangioblastoma in VHL disease.

Protocol for presurgical and anesthetic management of pheochromocytomas and sympathetic paragangliomas: a multidisciplinary approach

OBJECTIVE

To offer a practical guide for the presurgical and anesthetic management of pheochromocytomas and sympathetic paragangliomas (PGLs).

METHODS

This protocol was based on a comprehensive review of the literature and on our own multidisciplinary team's experience from managing pheochromocytoma and sympathetic PGLs at a referral center.

RESULTS

Patients with pheochromocytomas and sympathetic paragangliomas (PGLs) may develop potentially life-threatening complications, especially during surgical procedures. A complete biochemical, radiological, genetic, and cardiological assessment is recommended in the preoperative stage as it provides an evaluation of the risk of surgical complications and malignancy, allowing individualization of the presurgical treatment. Treatment with α-blockade and proper volume expansion in the preoperative stage significantly reduces the perioperative morbidity. During surgery, the anesthesiologist should look for a deep anesthetic level that inhibits the cardiovascular effects of catecholamines to minimize the risk of intraoperative complications.

CONCLUSIONS

An optimal presurgical evaluation of pheochromocytomas/ sympathetic PGL requires a multidisciplinary approach, including a complete hormonal, radiological, cardiac, genetic, and functioning evaluation in most cases. A proper preoperative evaluation in combination with strict blood pressure and heart rate control, and blood volume status optimization, will significantly reduce the risk of intraoperative and perioperative complications. In those patients who unfortunately develop intraoperative complications, the role of the anesthesiologist is essential since the selection of the appropriate management has a direct impact on morbimortality reduction.