Computed tomography imaging of gastrointestinal stromal tumors with pathology correlation

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors that typically arise in association with the muscularis propria of gastrointestinal (GI) tract wall. They occur most frequently in the stomach (60%) but also can occur in the small bowel (30%) or elsewhere, including the colon and rectum (5%) and esophagus (<5%). In addition, a GIST may occur as a primary tumor of the omentum, mesentery, or retroperitoneum. They account for 1%-3% of gastric neoplasms, 20% of small bowel tumors, and 0.2%-1% of colorectal tumors. These tumors arise pathologically from the wall of the GI tract and can be characterized as benign, borderline, or with low or high malignant potential based on the pathologic appearance. Computed tomography (CT) plays an important role for the diagnosis and staging of these neoplasms because it can identify the tumor and assess for local spread or distant metastases. This article reviews the role of CT in the detection and characterization of GISTs. The optimal CT technique for visualization of small bowel tumors is reviewed, and a variety of GISTs are illustrated. Pathologic correlation is also included.