Gastrointestinal stromal tumors (GIST) are relatively rare lesions of mesenchymal origin, being more frequent in the stomach and small intestine. These are clinically asymptomatic lesions, and in advanced stages may present with nausea, vomiting, bleeding, abdominal pain, a palpable mass, and even intestinal obstruction. The only effective treatment consists of a complete tumor resection. We report two cases of GIST located in the distal rectum and evaluated with three-dimensional anorectal ultrasonography, a procedure of great value in identifying the size of the lesion, its involvement toward nearby structures and lymph node invasion.
Gastrointestinal stromal tumor; CD 34; CD 117