title: [Immunohistochemical Expression of CD117 (c-kit) in 75 Renal Cell Tumors].
abstract: OBJECTIVE
  c-kit encodes the membrane-bound tyrosine kinase c-kit, whose expression has been identified in several human neoplasms. We analyzed the immunohistochemical expression of c-kit in renal cell tumors.
  
  
  METHODS
  75 cases of renal cell tumors were obtained from the surgical pathology archives at the ABC Medical Center in Mexico, for the period 2001 to 2011. We selected one representative paraffin block of the tumor and immunohistochemical staining for CD117 (c-kit) was performed. Immunopositivity was analyzed according cell location, intensity and percentage.
  
  
  RESULTS
  c-kit was positive in 20 cases (26.66%), all the oncocytomas and chromophobe renal cell carcinoma were positive. A total of 8.27% of conventional clear cell renal cell carcinomas showed cytoplasmic positivity and one case of papillary renal cell carcinoma was positive. In chromophobe renal cell carcinoma c-kit was positive in the membrane and 44.44% showed combined staining. In oncocytoma four cases showed cytoplasmic positivity, with heterogeneous and less intense staining than chromophobe renal cell carcinoma.
  
  
  CONCLUSIONS
  c-kit is a useful marker for the diagnosis of chromophobe renal cell carcinoma and oncocytoma vs. other renal cell tumors. Also it is important to define the cell location, intensity, and percentage of neoplastic cells for the differential between chromophobe renal cell carcinoma and oncocytoma.
authors: Departamento de Patología Quirúrgica y Molecular, Centro Médico ABC (The American British Cowdray Medical Center), México, D.F.; Departamento de Patología Quirúrgica, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México, D.F.
authors: Diana
authors: D
authors: Aguilar-León
authors: Departamento de Patología Quirúrgica y Molecular, Centro Médico ABC (The American British Cowdray Medical Center), México, D.F.
authors: Gabriela
authors: G
authors: Del Ángel-Millán
authors: Departamento de Patología Quirúrgica y Molecular, Centro Médico ABC (The American British Cowdray Medical Center), México, D.F.
authors: Iván
authors: I
authors: Zepeda-Quiroz
authors: Departamento de Patología Quirúrgica y Molecular, Centro Médico ABC (The American British Cowdray Medical Center), México, D.F.
authors: Danny
authors: D
authors: Soria-Céspedes