[Low grade collecting duct carcinoma of the kidney. Presentation of one case and literature revision].

Collecting duct renal cell carcinoma is an uncommon variant of renal carcinoma. Typically its behaviour is more aggressive than other forms of renal carcinoma and usually it is diagnosed at advanced stages. A 57-year-old man visited our hospital by right lumbar pain. Abdominal CT showed a enhanced mass on the right kidney. A right partial nephrectomy was done. Histological examination of the surgical specimen showed a low grade collecting duct carcinoma of the kidney. This is a new entity, with unknown behaviour but seems to be less aggressive than classical collecting duct carcinoma of the kidney. The clinical, radiological, pathological and immunohistochemical characteristics of this tumor are reported, and the literature is reviewed.