Abstract

Primary carcinoid tumor of the kidney is a very rare disease. Until now, only 41 cases have been reported worldwide, and nine of these arose in a horseshoe kidney. In Korea, 3 cases have been reported to date, and all of these arose in a horseshoe kidney. We present a case of primary carcinoid tumor occurring in a normal kidney of a 45 year old man. A tumor was incidentally found close to the hilum of the left kidney. Histologically, the tumor exhibited trabecular and ribbon-like pattern of cuboidal or columnar cells. Mitotic activity was rarely seen. The tumor cells were positive for synaptophysin and chromogranin A. Numerous dense-core neurosecretary granules were observed by the electron microscopic examination. To our knowledge, the present case is the first report of primary renal carcinoid tumor arising in a normal kidney in Korea.

• Keywords: Kidney;Carcinoid;