title: Extraneural hemangioblastoma of the kidney: the challenge for clinicopathological diagnosis.
abstract: BACKGROUND
  Hemangioblastoma is a benign cerebellar tumour which may occur as a sporadic entity or in association with von Hippel-Lindau (VHL) disease in approximately 25% of cases. Renal hemangioblastoma (RH) is an extremely rare and newly recognised tumour. Here, we describe five cases of RH, one discovered by CT in an accident and the other four detected during routine examinations.
  
  
  METHODS
  Five cases of renal hemangioblastoma retrieved from the Department of Pathology, Fudan University Shanghai Cancer Center were studied and the literatures were reviewed. Immunohistochemistry was used to differentiate and confirm this tumour.
  
  
  RESULTS
  Pathological examination following tumour resection revealed RH in all cases, the first patient was also diagnosed with renal cell carcinoma (RCC), suggesting the possibility of VHL syndrome, but PCR sequencing analysis of the VHL gene confirmed no mutation in any of the three exons, implying sporadic disease. Histologically, the tumours were circumscribed, composed of sheets of oval or polygonal cells and a prominent vascular network. Tumour cells had pleomorphic nuclei, but mitotic figures were rare. The diagnosis of hemangioblastoma was confirmed by immunohistochemistry.
  
  
  CONCLUSIONS
  RH is very rare and is challenging to differentially diagnose. Distinguishing RCC and RH is difficult and each has a different prognosis, so differentiating between them is essential for avoiding over-diagnosis and unnecessary treatment.
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Pei-Pei
authors.initials: PP
authors.lastname: Zhang
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Xiaoqun
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Chao-Fu
authors.initials: CF
authors.lastname: Wang
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D002292:Carcinoma, Renal Cell / Q000473:pathology; D002528:Cerebellar Neoplasms / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D018325:Hemangioblastoma / Q000473:pathology*; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D006623:von Hippel-Lindau Disease / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor
keywords: IMMUNOHISTOCHEMISTRY; KIDNEY; RENAL CANCER