Angiomyolipoma of the colon: report of a case.

Angiomyolipomas are benign mesenchymal tumors mostly arising from the kidney. Angiomyolipoma of the colon is extremely rare. Here we report the findings of a 51-year-old man who presented with a submucosal tumor covered with normal mucosa and hemorrhage in the descending colon. He underwent a partial resection of the descending colon. A histopathological examination showed that the tumor of 5.7 cm in diameter included smooth muscle (spindle cell type), mature adipose tissue, and vessels, and therefore a diagnosis of angiomyolipoma was made. A submucosal type of angiomyolipoma of the colon is extremely rare. If a renal angiomyolipoma is larger than 4 cm, there is a risk of rupture. When colonoscopy shows a submucosal tumor of the colon with hemorrhage, angiomyolipoma should be considered. If an angiomyolipoma of the colon is large, surgical resection should be considered as a treatment option due to the risk of hemorrhage.