What are the cross sectional imaging features of GI tract lymphoma?
GI tract lymphoma most commonly occurs in the stomach (70%) (most often in the gastric antrum and body), followed by small bowel (20%) (most often in the ileum) and ileocecal region (10%). It is most commonly due to non-Hodgkin’s lymphoma of B cell origin.
Bowel wall thickening or focal soft tissue enhancing mass, which is typically homogeneous, may be seen. In the stomach, the wall thickening may be focal, segmental, or diffuse, and luminal narrowing may be present. In the small bowel, focal or segmental involvement may occur along with aneurysmal dilation of the affected bowel loops due to tumor infiltration of the myenteric plexus, although bowel obstruction is uncommonly seen. Intraluminal and/or exophytic soft tissue tumor components are commonly present, and direct spread of tumor to adjacent organs or to the peritoneal space may be encountered. Lymphadenopathy is commonly present, and involvement of distant sites may also be seen