title: Case report of renal cell carcinoma diagnosed in voided urine confirmed by CD10 immunocytochemistry.
abstract: BACKGROUND
  Preoperative diagnosis of renal cell carcinoma (RCC) by exfoliative urine cytology is difficult, as infiltration of RCC into the pelvicalyceal system is uncommon. The exfoliation of RCC cells in urine is a rare phenomenon and when it does occur, it is likely to be missed. Cytologic examination of the urine coupled with ancillary immunocytochemistry can clinch the diagnosis leading to appropriate clinical management.
  
  
  METHODS
  A 50-year-old man presented with complaints of hematuria and abdominal pain of 6 months' duration. Ultrasonographic examination of the abdomen and pelvis showed a well-defined mass lesion in the upper pole of the left kidney, suggestive of neoplastic etiology. In the given clinical context of renal mass, urine cytology was suggestive of RCC and biopsy confirmation was suggested. One cytology smear subjected to immunocytochemistry with anti-CD10 antibody which showed strong diffuse cytoplasmic positivity in these cells confirmed the diagnosis of RCC. Subsequently, fine needle aspiration cytology of the kidney mass was reported as RCC.
  
  
  CONCLUSIONS
  RCC has distinct cytologic features that facilitate a diagnosis in urine in an appropriate clinical and radiological context. Their recognition in the urine smear is important to avoid costly and invasive modalities like image-guided needle biopsy.
authors.affiliation: Department of Cytopathology, Tata Memorial Hospital, Mumbai, India.
authors.forename: Sanjivani B
authors.initials: SB
authors.lastname: Dubal
authors.forename: Saleem
authors.initials: S
authors.lastname: Pathuthara
authors.forename: Dulhan
authors.initials: D
authors.lastname: Ajit
authors.forename: Santosh
authors.initials: S
authors.lastname: Menon
authors.forename: Shubhada V
authors.initials: SV
authors.lastname: Kane
mesh_terms: D002292:Carcinoma, Renal Cell / Q000378:metabolism / Q000652:urine*; D006801:Humans; D007124:Immunoenzyme Techniques; D007680:Kidney Neoplasms / Q000378:metabolism / Q000652:urine*; D008297:Male; D008875:Middle Aged; D015260:Neprilysin / Q000652:urine*; D011379:Prognosis; D014556:Urine / Q000166:cytology*
chemical_list: D015260:Neprilysin