[Chromophobe renal cell carcinoma: immunohistochemical study of 7 cases]

A series of 7 cases of chromophobe cell carcinoma with clinicopathological correlation is studied. The immunohistochemistry analysis was carried out evaluating in all cases: low and high cytoqueratines (AE1, AE3), membrane epithelial antigen (EMA), vimentin, carcinoembrionary antigen (CEA), proliferative cell nuclear antigen (PCNA) and the oncoproteins p53 and focal c-erbB2. In all cases a diffuse positivity for EMA, AE3 and focal for AE1 was observed, while vimentin and CEA were negative. The positivity for PCNA was always less than 25% of tumoral cells. The oncoprotein p53 was in all cases negative and only in one case a mild and focal positivity for c-erbB2 was observed.

1) The negativity for vimentin and positivity for EMA, AE1 and AE3 allows to differentiate this carcinoma from clear cell carcinoma. This corroborate a distinct histogenesis, thus suggesting their origin in the intercalar cells of distal collector tubules. 2) The low values of PCNA and the negativity for both oncoproteins p53 and c-erbB2 supports the low aggresivity of this tumor and a better prognostic than other types of kidney carcinomas.