Putative chromophobe cell renal carcinoma: are they or are they not?
OBJECTIVE: According to the literature, the typical histological findings and simple colloidal iron staining permit the identification of chromophobe cell renal carcinoma, a genetically well-established entity. Our doubts on whether this tumor type can be recognized by conventional methods are presented in this study. METHODS: 130 cases of renal carcinoma were treated from 1977 to 1997. Of these, 12 showed characteristic general histological features compatible with chromophobe cell renal carcinoma and reticulated and intense, diffuse cytoplasmic positivity on colloidal iron staining. These tumors were reviewed for the following: 1) gross appearance, 2) architecture, 3) cytoplasmic characteristics, 4) nuclear characteristics, 5) colloidal iron histochemical staining which is considered fundamental and exclusive, 6) immunohistochemical phenotype. Ultrastructural study of material fixed in paraffin was also performed. RESULTS: One case met all 6 criteria, 3 met 5 of them, 6 cases met 4,
