RENAL ONCOCYTOMATOSIS

RENAL oncocytoma is an uncommon benign neoplasm of the kidney of unkno wn etiology. Zippel was the first to report a case of renal oncocytoma in 1942.(1) Since 1976, when the review by Klein and Valensi(2) drew attention to this entity, well over 600 cases have been reported.(3) A n oncocytoma typically presents as a solitary, solid renal mass, which is incidentally discovered in up to 66% of patients.(4) To our knowle dge, only eight cases of bilateral, multicentric renal oncocytomas hav e been reported.(5-11) In 1982, Warfel and Eble reported the only case of bilateral diffuse renal involvement by oncocytomas; innumerable mi croscopic and macroscopic oncocytomas were discovered at autopsy in a 71-year-old woman who died of unrelated causes.(11) These investigator s coined the term ''renal oncocytomatosis'' to describe this process. We report the imaging and pathology findings in a 46-year-old man with incidentally discovered marked bilateral nephromegaly due to diffuse infiltration by oncocytomas.