Gastrointestinal stromal tumors (GISTs) are characterized by remarkable var
iability in their differentiation potential, but most of these lesions do n
ot display convincing smooth muscle or neuronal differentiation. The GISTs
arising from the rectum or anal canal are extremely uncommon. We present a
case of immunohistochemically proven GIST of the rectum, which was characte
rized by homogenous isointensity mass without necrosis or hemorrhage on T2-
weighted image and by enhancement on gadolinium-enhanced study.