RADIOLOGY: GASTROINTESTINAL: GI: Case# 32891: GASTRIC LYMPHOMA. 63 year old man with abdominal pain. The gastric fundus and lesser curvature are replaced by a homogeneous soft tissue mass causing thickening of the wall and extending to the gastric lumen. There is a large mass extending inferiorly from the stomach into the omentum. This appears continuous with the stomach. It measures approximately 14 cm transverse x 7 cm AP x 9 cm cranio-caudal. There are focal areas of low attenuation within this mass consistent with necrosis. There is mesenteric adenopathy and retroperitoneal adenopathy present. There are numerous other small retroperitoneal lymph nodes present. There are streaky changes within the fat of the mesentery, which can be seen with lymphomatous involvement. The stomach is the most common site of gastrointestinal involvement with lymphoma. Gastric involvement is usually manifest by submucosal tumor spread. Focal gastric wall thickening with distortion of the normal rugal-fold pattern is the hallmark of gastric lymphoma. Many patients have associated adenopathy in the greater omentum, gastrohepatic ligament, or gastrosplenic ligament. The gastric wall thickening generally returns to normal after treatment (either radiation, surgery, or chemotherapy).