Diagnosis and Treatment of Rectal Gastrointestinal Stromal Tumors

A 69-year-old man presented with a rectal mass that was noted on physical examination. Flexible sigmoidoscopy confirmed the presence of a well-defined mass 3 cm from the anal verge (). Magnetic resonance imaging of the pelvis identified a 5.8-cm heterogeneous mass with intersphincteric extension. Positron emission tomography-computed tomography revealed no evidence of distant metastatic disease. Endoscopic ultrasound (EUS) with fine-needle...