Pancreatic neuroendocrine tumors in French VHL mutation carriers: a multicentric retrospective study.

BACKGROUND: Von Hippel-Lindau disease (VHL) is a rare autosomal dominant hereditary cancer-predisposition syndrome caused by germline pathogenic variants (PV) in VHL gene. It is associated with a high penetrance of benign and malignant vascular tumors in multiples organs, including pancreatic neuroendocrine tumors (PanNETs), whose long-term natural history is ill-known. METHODS: Patients with both documented germline PV in VHL gene and PanNETs included in the French PREDIR database between 1995 and 2022 were included. Primary endpoint was the proportion of patients with PanNET-related metastases and secondary endpoint was overall survival (OS). Genotype/phenotype correlations were studied. RESULTS: We included 121 patients with 259 PanNETs. Median age at diagnosis was 38 years. Median follow-up was 89.5 months. PanNET surgical resection was performed in 51 patients. Overall, 29 patients (24%) had metastases (5 synchronous, 10 metachronous), with a higher risk in case of larger PanNET size (p=0.0089; best threshold 28 mm) and grade 2 PanNET (p=0.048), and a pejorative prognostic impact (p=0.043). Patients with PV in VHL exon 1 had larger PanNETs (p=0.018), more often metastatic disease (48% vs 11.5%; p < 0.001) and a trend toward shorter OS (p=0.16). CONCLUSION: The risk of metastases associated to VHL-related PanNETs remains low (24%) but increases with tumor size >28 mm, higher grade and in case of PV located VHL exon 1. These data might help improving the management of these patients, who should be referred to an expert center.

Von-Hipple Lindau syndrome with family history: a case report and seventeen years follow-up study.

Background: Von-Hipple Lindau syndrome is an uncommon autosomal dominant disorder. 17 years ago we diagnosed a young woman with VHL syndrome validated by Sanger sequencing, her family members were genetically tested as well, and 187 healthy people were randomly selected for VHL genetic testing as controls. We analyze the clinical and genetic characteristics of VHL syndrome in a Chinese lineage and with 17-year follow-up. Case presentation: A woman was finally diagnosed with VHL syndrome due to the detection of a missense mutation c.353T > C in exon 2 of the short arm of chromosome 3, which resulted in a leucine substitution at amino acid 118 of the encoded protein by a proline, which may be thought the main cause of the disease. The same mutation was observed in two other family members, their clinical symptoms are not entirely identical. However, this mutation was not found in other family members or 187 healthy controls. She clinically presented with central nervous system hemangioblastomas, clear renal cell carcinoma, and pancreatic neuroendocrine neoplasms, despite the multi-organ involvement and several relapses during the disease, the patients survive well for she was treated with aggressive surgery early in the course of the plaguing symptoms, whereas patients who are not aggressively treated have a poorer prognosis. Conclusion: The clinical presentation of VHL syndrome is atypical, and early identification and treatment of VHL syndrome is possible by genetic testing techniques. Multiple relapses occurred during the course of the disease, but early diagnosis and aggressive treatment allowed the patients to survive well.

Biallelic ELOC-Inactivated Renal Cell Carcinoma: Molecular Features Supporting Classification as a Distinct Entity.

Approximately 70% of clear cell renal cell carcinoma (ccRCC) is characterized by the biallelic inactivation of von Hippel-Lindau (VHL) on chromosome 3p. ELOC-mutated (Elongin C-mutated) renal cell carcinoma containing biallelic ELOC inactivations with chromosome 8q deletions is considered a novel subtype of renal cancer possessing a morphologic overlap with ccRCC, renal cell carcinoma (RCC) with fibromyomatous stroma exhibiting Tuberous Sclerosis Complex (TSC)/mammalian Target of Rapamycin (mTOR) mutations, and clear cell papillary tumor. However, the frequency and consequences of ELOC alterations in wild-type VHL and mutated VHL RCC are unclear. In this study, we characterize 123 renal tumors with clear cell morphology and known VHL mutation status to assess the morphologic and molecular consequences of ELOC inactivation. Using OncoScan and whole-exome sequencing, we identify 18 ELOC-deleted RCCs, 3 of which contain ELOC mutations resulting in the biallelic inactivation of ELOC. Biallelic ELOC and biallelic VHL aberrations were mutually exclusive; however, 2 ELOC-mutated RCCs showed monoallelic VHL alterations. Furthermore, no mutations in TSC1, TSC2, or mTOR were identified in ELOC-mutated RCC with biallelic ELOC inactivation. Using High Ambiguity Driven biomolecular DOCKing, we report a novel ELOC variant containing a duplication event disrupting ELOC-VHL interaction alongside the frequently seen Y79C alteration. Using hyper reaction monitoring mass spectrometry, we show RCCs with biallelic ELOC alterations have significantly reduced ELOC expression but similar carbonic anhydrase 9 and vascular endothelial growth factor A expression compared with classical ccRCC with biallelic VHL inactivation. The absence of biallelic VHL and TSC1, TSC2, or mTOR inactivation in RCC with biallelic ELOC inactivation (ELOC mutation in combination with ELOC deletions on chromosome 8q) supports the notion of a novel, molecularly defined tumor entity.

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.

An optimized protocol for evaluating pathogenicity of VHL germline variants in patients suspected with von Hippel-Lindau syndrome: Using somatic genome to inform the role of germline variants.

The interpretation of hereditary genetic sequencing variants is often limited due to the absence of functional data and other key evidence to assess the role of variants in disease. Cancer genetics is unique, as two sets of genomic information are often available from a cancer patient: somatic and germline. Despite the progress made in the integrated analysis of somatic and germline findings, the assessment of pathogenicity of germline variants in high penetrance genes remains grossly underutilized. Indeed, standard ACMG/AMP guidelines for interpreting germline sequence variants do not address the evidence derived from tumor data in cancer. Previously, we have demonstrated the utility of somatic tumor data as supporting evidence to elucidate the role of germline variants in patients suspected with VHL syndrome and other cancers. We have leveraged the key elements of cancer genetics in these cases: genes with expected high disease penetrance and those with a known biallelic mechanism of tumorigenicity. Here we provide our optimized protocol for evaluating the pathogenicity of germline VHL variants using informative somatic profiling data. This protocol provides details of case selection, assessment of personal and family evidence, somatic tumor profiles, and loss of heterozygosity (LOH) as supporting evidence for the re-evaluation of germline variants.

Assessment of genomic alterations in non-syndromic von Hippel-Lindau: Insight from integrating somatic and germline next generation sequencing genomic data.

Von Hippel-Lindau (VHL) syndrome is a hereditary cancer genetic condition associated with inactivating pathogenic alterations in the VHL tumor suppressor gene located at 3p (short arm of chromosome 3). Classic features of VHL include clear cell renal cell carcinoma, hemangioblastomas of the brain, spinal cord, and retina, pheochromocytoma, pancreatic cysts, and neuroendocrine tumors. Two sets of genomic information may be available from patients with VHL: the germline data showing the constitutional genetic profile and somatic profile obtained from patient tumor(s). Here we present both somatic and germline dataset from heterozygous carriers of germline VHL variants who exhibit non-syndromic VHL phenotypes. This data description article accompanies the paper "Pathogenicity of VHL variants in families with non-syndromic von Hippel-Lindau phenotypes: an integrated evaluation of germline and somatic genomic results'' by Huma Q. Rana, Diane R. Koeller, Alison Schwartz, Danielle K. Manning, Katherine A. Schneider, Katherine M. Krajewski, Toni K. Choueiri, Neal I. Lindeman, Judy E. Garber, Arezou A. Ghazani. We provide next generation sequencing (NGS) data obtained from DNA from tumors (renal cancer, bladder cancer, and cerebral hemangioblastoma) of three VHL carriers. The somatic dataset was analyzed for single nucleotide variants (SNVs) and copy number variants (CNVs) in 447 cancer genes, and structural variation (SVs) in 191 regions across 60 genes for rearrangements. We also present germline raw NGS data and analyzed SNV and CNV data in exonic regions of 133 hereditary cancer genes obtained from the peripheral blood of two VHL carriers.

Familial erythrocytosis 2 and von Hippel-Lindau disease in the same pediatric patient / Eritrocitosis familiar 2 y enfermedad de von Hippel-Lindau en el mismo paciente

Abstract Background: Patients with familial erythrocytosis type 2 have no increased risk of von Hippel-Lindau-associated tumors, although mutations in the VHL gene cause both pathologies. Case report: We present a case of a compound heterozygote patient with von Hippel-Lindau disease and familial erythrocytosis type 2. One of the mutations found in our patient, c.416C>G (p.Ser139Cys) of the VHL gene, has not been previously reported. This case is the second one reported where von Hippel-Lindau disease and familial erythrocytosis type 2 coexist in the same individual. Conclusions: Despite the low frequency of familial erythrocytosis type 2 in patients with von Hippel-Lindau disease, the possibility of this diagnosis should be considered to avoid unnecessary invasive studies to explain the polyglobulia in these patients and guarantee an adequate follow-up and vigilance of both diseases.

Resumen Introducción: Los pacientes con eritrocitosis familiar tipo 2 no muestran un riesgo incrementado de desarrollar tumores asociados con la enfermedad de von Hippel-Lindau, a pesar de que ambas afecciones están causadas por variantes patogénicas en el gen VHL. Caso clínico: Se presenta el caso de un paciente heterocigoto compuesto con enfermedad de von Hippel-Lindau y eritrocitosis familiar tipo 2. Una de las variantes patogénicas en el paciente, VHL c.416C>G (p.Ser139Cys), no ha sido previamente reportada. Este es el segundo reporte de caso en que la enfermedad de von Hippel-Lindau y la eritrocitosis familiar tipo 2 coexisten en el mismo individuo. Conclusiones: A pesar de la baja frecuencia de la eritrocitosis familiar tipo 2 en pacientes con enfermedad de von Hippel-Lindau, la posibilidad del diagnóstico debe considerarse con el fin de evitar estudios invasivos innecesarios para explicar la presencia de poliglobulia en estos pacientes y para garantizar un adecuado seguimiento y una correcta vigilancia de ambas enfermedades.

Anorexia as the first clinical manifestation of von Hippel-Lindau syndrome.

Hemangioblastomas (HBs) of the brain may present without neurological symptoms over a long period of time due to their benignity and slow growth. We herein present the case of a female patient who developed a HB of the fourth ventricle presenting only with severe weight loss and anorexia. The patient was screened for mutations in all 3 exons of the VHL gene using Sanger sequencing, and was found to have a nonsense mutation in the VHL gene (single-nucleotide change causing a premature stop codon: c.481C>T; p.Arg161*), causing formation of a truncated protein, consistent with von Hippel-Lindau syndrome (VHLs). The patient was first misdiagnosed with anorexia nervosa (AN) due to the lack of other symptoms. Molecular diagnosis allows further investigation of other VHLs-related tumors and timely, appropriate treatment. However, misdiagnosing anorexia nervosa may lead to poor prognosis and even death; thus, differential diagnosis is crucial in all such cases. The present case report provides evidence that fourth ventricular lesions may affect food intake control and satiety, and highlights the importance of accurate molecular diagnosis.

Sharing the initial experience of pan-cancer panel analysis in high-risk renal cell carcinoma in the Korean population.

BACKGROUND: This study aimed to assess the feasibility of a pan-cancer panel assay for high-risk renal cell carcinoma (RCC) in the Korean population. We also analyzed the clinical and genetic factors contributing to metastasis in clear cell RCC. METHODS: Thirty-one patients with advanced RCC who underwent radical nephrectomy were analyzed. A 1.8 Mb multi-cancer panel (including 25 RCC-related genes, such as VHL, PBRM1, SETD2, and MET), comprising 181 target genes, 23 fusion genes, and 45 drug target lesions developed by Seoul National University Hospital, was used for this study. RESULTS: We extracted DNA from 30 of the 31 (96.7%) RCC specimens. Twenty-one patients (average age 63.3 ± 11.3 years) with clear cell RCC, 5 with papillary RCC, 3 with chromophobe RCC, and one patient, each with MiT family translocation carcinoma RCC and succinate dehydrogenase deficiency RCC, were analyzed. The sequencing depth was 430.8 ± 206.6 and 97 mutations (7.3 ± 2.7 mutations per patient) were detected. The most commonly mutated genes were VHL (46%), PBRM1 (30%), and BAP1, NOTCH4, and POLQ (23.33% each). Compared with TNM stage matched data from TCGA of clear cell RCC, VHL and PBRM1 are most common in both cohorts. Univariate and multivariate analyses revealed that tumor size (Hazard ratio = 2.47, p = 0.04) and PBRM1 (Hazard ratio = 28.69, p = 0.05) were related to metastasis in clear cell RCC. CONCLUSION: The pan-cancer panel comprised of RCC-related genes is a feasible and promising tool to evaluate genetic alterations in advanced RCC. However, large-scale studies and a focus on the clinical utility of this cancer panels is needed.

Clinical diagnosis, treatment and screening of the VHL gene in three von Hippel-Lindau disease pedigrees.

The present study aimed to investigate the clinical characteristics of von Hippel-Lindau (VHL) disease and the clinical significance of VHL gene detection. The clinical materials of patients with VHL disease were collected from 3 different families between May 1985 and October 2017. A systematic pedigree study and VHL gene detection at the germline level were performed together with a literature review. Of the 22 patients from 3 VHL pedigrees, 10 exhibited VHL gene mutations (3 genotypes) at the germline level. The genotypes of pedigree were VHL-p.R161Q (c.482G>A), VHL-p.N78S (c.233A>G), and VHL-p.R167Q (c.500G>A). During the follow-up period, the symptoms were stable in 10 patients, including 2 cases of central nervous system hemangioblastomas (CNS-HB), 3 cases of bilateral multiple renal cell carcinoma (RCC) and 5 cases of adrenal pheochromocytoma without local recurrence or distant metastasis. Patients with p.R161Q and p.N78S were not associated with CNS-HB, which was different from the clinical phenotype of previously reported families. RCC were Fuhrman II grade, which was consistent with the previous study. The results of the present study indicated that the standardization of early diagnosis and the improvement of long-term efficacy may be achieved by combining clinical screening and VHL gene detection.

Third-line sunitinib treatment in a VHL-mutated metastatic intrahepatic cholangiocarcinoma: a case report and literature review.

Intrahepatic cholangiocarcinoma (iCCA) is a highly aggressive malignancy with a poor prognosis. There is no standard treatment beyond first-line chemotherapy and no molecular-targeted drug approved for advanced iCCA. We herein present a case of a 46-y-old Asian iCCA patient with multiple metastases in lung, bone, and liver. The patient progressed rapidly after first- and second-line chemotherapy. According to next-generation sequencing result of somatic Von Hippel-Lindau (VHL) gene mutation, the patient was administered third-line sunitinib and obtained a relatively longer survival of 9 months after taking sunitinib. Additionally, we briefly summarized the current targeted treatment of iCCA. To our knowledge, this is the first report of VHL mutation and sunitinib usage in metastatic iCCA patient. As a highly heterogeneous and aggressive malignancy, we strongly recommend making clinical decisions based on precision medicine concept in advanced iCCA.

von Hippel-Lindau Syndrome: Genetic Study of Case With a Rare Pathogenic Variant With Optic Nerve Hemangioblastoma, a Rare Phenotypic Expression.

von Hippel-Lindau syndrome (VHLS) is a rare, autosomal dominant genetic disease with high penetrance and variable phenotypic expression caused by variants in the VHL gene. VHLS is associated with the presence of vascular tumors, often hemangioblastoma of the central nervous system, retina, or spinal cord and, less frequently, pancreatic cystic neoplasm, pancreatic neuroendocrine tumor, clear cell carcinoma of the kidney, endolymphatic sac tumor, pheochromocytoma, and paraganglioma. The authors report a case of a patient with VHLS with a rare pathogenic variant in the VHL gene and with an optic nerve hemangioblastoma, a rare phenotypic expression. Case report: A 49-year-old woman was diagnosed with cystic neoplasm of the pancreas, renal cell carcinoma of the right kidney, and hemangioblastoma of the left optic nerve. The patient's family history revealed siblings with VHLS manifestations. The index case was her mother who died at age 63 of clear cell renal carcinoma. The information was obtained by consulting the patient's medical register and by interviews with the patient and her relatives. The presence of left optic nerve hemangioblastoma was suggested by CT scan of the skull and orbit. The sequencing of the VHL gene was performed in the peripheral blood by the polymerase chain reaction (PCR) technique, and the duplication and deletion research was performed using the multiplex ligation-dependent probe amplification (MPLA) technique. The presence of a rare pathogenic variant c.263G> A (p.Trp88Ter) was observed in heterozygosity in the VHL gene that determined a premature stop codon. CT scan of the skull and orbits suggested the presence of HB in the optic nerve of the left eye. The results of the CT scan of the skull and orbits show thickening with tortuosity of the left optic nerve, with a small area of nodular enhancement. The right optic nerve had a conserved aspect. Conclusion: This is the fourth case described of this rare pathogenic variant of the VHL gene, according to the Human Gene Mutation Database and VHLdb database records and with an optic nerve hemangioblastoma of the optic nerve, a very rare phenotypic expression of the VHLS.

Clear cell chondrosarcoma in Von Hippel-Lindau disease.

A diagnosis of clear cell chondrosarcoma of the ulna was made in a patient with Von Hippel-Lindau disease (VHL). After surgery, genetic analysis of the tumor tissue showed loss of heterozygosity at the VHL gene locus. Immunohistochemical analysis confirmed loss of expression of the VHL protein in the tumor cells. In addition, abundant Cyclin D1 expression in the tumor was observed. Chondrosarcoma has been described before in a VHL patient and VHL protein expression has been correlated to tumor grade in a series of sporadic chondrosarcomas. In this report, we show that clear cell chondrosarcoma may be a rare but canonical VHL manifestation through a cell-autonomous mechanism involving somatic loss-of-heterozygosity of the VHL tumor suppressor gene. We discuss the relevance of this observation with regard to the pathogenesis of clear cell chondrosarcoma in the context of VHL.

Renal Cell Carcinoma with Clear Cell Papillary Features: Perspectives of a Differential Diagnosis.

Thirty-one cases of low-grade renal cell carcinoma (RCC) with clear cells and tubulopapillary/papillary architecture were analyzed retrospectively with immunohistochemical and genetic markers to gain more experience with the differential diagnosis of such cases. All samples coexpressed CK7 and CA9; the TFE3 or TFEB reactions were negative; the CD10 and the AMACR stainings were negative in 27 cases and 30 cases, respectively. The FISH assays for papillary RCC, available in 27 cases, and deletion of chromosome 3p, available in 29 cases, gave negative results. The results for 3p deletion, VHL gene mutation or VHL gene promoter region hypermethylation testing, along with the diffuse CD10-positivity in 2 cases confirmed 21 cases as clear cell papillary RCC (CCPRCC; CK7+, CA9+; no 3p loss, no VHL abnormality) and 10 cases as clear cell RCC (CCRCC; CK7+, CA9+; no 3p loss, VHL abnormality mutation/hypermethylation present). In CCPRCCs, the representative growth pattern was branching tubulo-acinar, commonly accompanied by cyst formation. The linear nuclear arrangement or cup-shaped staining of CA9 did not necessarily indicate CCPRCC, and the absence of these did not exclude the diagnosis of CCPPRC. One tumor infiltrated the renal sinus; the others exhibited pT1 stage; and metastatic outcome was not recorded. The CCRCC cases were in pT1 stage; 6 exhibited cup-shaped staining of CA9, and 1 displayed lymph node metastasis at the time of surgery. Distant metastatic disease was not observed. In summary, the VHL abnormalities distinguished the subset of CCRCC with diffuse CK7-positivity and no 3p loss from cases of CCPRCC.

Mouse- and patient-derived CAM xenografts for studying metastatic renal cell carcinoma.

Renal cell carcinoma is the seventh most common cancer in the United States, and its metastatic form has a very poor prognosis due to a lack of effective treatment and thorough understanding on metastatic mechanism. This chapter will demonstrate a novel concept that intratumoral heterogeneity is essential for metastasis in renal cell carcinoma. We will first introduce the in vitro system and the mouse model that led to the finding of the cooperative mechanism for metastasis. Then, the results from the CAM model illustrate the cooperative interactions that lead to metastasis also occur in this model. We believe that the CAM model, as a unique and sustainable system, can open up new opportunities to study the metastatic disease.

Ocular Manifestations of von Hippel-Lindau Disease.

In this review article, we aimed to analyze the available data on the ocular manifestations of von Hippel-Lindau (VHL) disease. In this disease, the VHL protein becomes inactivated by germline mutations of the VHL tumor suppressor gene on chromosome 3p25-26, resulting in an overproduction of VEGF in non-hypoxic conditions. Ocular manifestations are expected in roughly half of VHL patients. Retinal capillary hemangioblastomas (RCHs) are the most commonly observed tumors in VHL and are often the initial manifestation of the disease. Ablative therapy, surgical resection, and pharmacotherapy have been implemented to control tumors. Left untreated, RCHs will often enlarge, emphasizing the importance of early diagnosis and treatment to preserve vision. Complications of enlarging peripheral or optic nerve tumors may be severe. Large RCHs may disrupt normal retinal architecture, eventually leading to exudative retinal detachment. Rarely, non-retinal manifestations, such as neovascularization of the iris or cornea, may progress to neovascular glaucoma and vision loss. Ablative therapy of larger tumors carries increasing risks and offers limited success, often necessitating surgical resection. Because this life-threatening disease is not routinely encountered in clinical practice, clinicians will benefit from our review which brings awareness to the ocular presentation of VHL and lifelong screening recommendations for diagnosed patients.

Whole-exome sequencing and immunohistochemistry findings in von Hippel-Lindau disease.

BACKGROUND: von Hippel-Lindau (VHL) disease has a hereditary, autosomal dominant pattern, and multiple tumors can develop in multiple organs of a single patient. However, the exact mechanisms of tumorigenesis are unclear, and further studies are needed to clarify whether the same signaling pathways are involved in different VHL-related tumors. METHODS: Whole-exome sequencing (WES) of tumor and paired peripheral blood samples were performed for a VHL disease pedigree. A bioinformatics analysis was conducted to identify candidate somatic single-nucleotide variants (SNVs) present in all tumor tissues. Sanger sequencing was then used to validate the SNVs identified using WES. Immunohistochemistry was performed to analyze components of the mTOR pathway, which was abnormally activated in tumor tissues. RESULTS: Two hemangioblastomas and two renal cell carcinomas were sequenced. The bioinformatics analysis revealed a VHL somatic variant in all tumors; no other SNV was detected. Immunohistochemistry showed the abnormal expression of the phospho-S6 ribosomal protein in the hemangioblastomas, but not in the renal clear cell carcinomas. CONCLUSION: Except for a SNV in the VHL gene, no other somatic SNVs were detected using WES. The phospho-S6 ribosomal protein in the mTOR pathway is a potential target in VHL-related cerebellum hemangioblastomas.

Primary peritoneal epithelioid mesothelioma of clear cell type with a novel VHL gene mutation: a case report.

Clear cell variant of epithelioid mesothelioma is an extremely rare tumor with only isolated cases reported so far in the peritoneum. Here, we report a case of peritoneal epithelioid mesothelioma, clear cell variant, in a 63-year-old female patient with a novel VHL gene mutation and an unusual indolent clinical course. The patient, who has no clinical history of asbestos exposure, presented with a 27.2-cm upper abdominal mass and a 5.5-cm liver lesion. Retrospective review of the patient's abdominal computed tomographic scan 4 years ago showed 2 small abdominal lesions that were felt clinically to represent hemangiomas. These were retrospectively considered to have grown in size and represented the current abdominal mass. Both masses were subsequently biopsied and showed a proliferation of monomorphic epithelioid cells with distinct cell membranes, fine chromatin, and clear to finely vacuolated pale eosinophilic cytoplasm arranged in nests and solid sheets. Immunohistochemical staining confirmed it to be malignant mesothelioma. Clear cell variant of peritoneal epithelioid mesothelioma should always be considered in patients with an abdominal or pelvic mass with clear cell features. Given the rarity of such entity, its clinical course and prognosis remains unclear.

Clinical characteristics and genetic testing of an atypical familial von Hippel-Lindauzon renal cell carcinoma.

BACKGROUND: A case of familial bilateral von Hippel-Lindauzon (VHL) renal cell carcinoma (RCC) was retrospectively reviewed and the etiological diagnosis was based on clinical characteristics and genetic testing. METHODS: The clinical manifestations and imaging data were gained from the hospital information system (HIS). Peripheral blood samples were collected and genomic DNA and RNA were extracted. Additionally, mutations of VHL gene such as tiny insertion and deletion of base, point mutation and large deletion of gene were then detected and analyzed by DNA sequencing, real-time quantitative PCR and RT-PCR. RESULTS: Real-time quantitative PCR and RT-PCR products sequencing showed that the number of VHL gene copies in peripheral blood of the patient was decreased, and pathological germline mutation was detected caused by single copy deletion of exon 2 of VHL gene. The patient was diagnosed as atypical VHL RCC according to clinical manifestations and genetic testing outcomes. CONCLUSIONS: VHL RCC can be diagnosed based on its clinical manifestations and genetic testing results.

VHL Dependent Expression of REDD1 and PDK3 Proteins in Clear-cell Renal Cell Carcinoma.

BACKGROUND: Sporadic clear-cell renal cell carcinoma (ccRCC) is associated with mutations in the VHL gene, upregulated mammalian target of rapamycin (mTOR) activity and glycolytic metabolism. Here, we analyze the effect of VHL mutational status on the expression level of mTOR, eIF4E-BP1, AMPK, REDD1, and PDK3 proteins. METHODS: Total proteins were isolated from 21 tumorous samples with biallelic inactivation, 10 with monoallelic inactivation and 6 tumors with a wild-type VHL (wtVHL) gene obtained from patients who underwent total nephrectomy. The expressions of target proteins were assessed using Western blot. RESULTS: Expressions of mTOR, eIF4EBP1 and AMPK were VHL independent. Tumors with monoallelic inactivation of VHL underexpressed REDD1 in comparison to wtVHL tumors (P = 0.042), tumors with biallelic VHL inactivation (P < 0.005) and control tissue (P = 0.004). Additionally, REDD1 expression was higher in tumors with VHL biallelic inactivation than in control tissue (P = 0.008). Only in wt tumor samples PDK3 was overexpressed in comparison to tumors with biallelic inactivation of VHL gene (P = 0.012) and controls (P = 0.016). In wtVHL ccRCC, multivariate linear regression analysis revealed that 97.4% of variability in PDK3 expression can be explained by variations in AMPK amount. CONCLUSION: Expressions of mTOR, eIF4EBP1 and AMPK were VHL independent. We have shown for the first time VHL dependent expression of PDK3 and we provide additional evidence that VHL mutational status affects REDD1 expression in sporadic ccRCC.