RADIOLOGY: GASTROINTESTINAL: GI: Case# 32843: GASTRIC LYMPHOMA, RADIATION CHANGES IN LIVER. This patient is a 70 year old white male with lymphoma diagnosed four years ago and a recently diagnosed gastric mass. He has undergone a course of radiation. There is a 3.2 x 2.2cm soft tissue mass present on the lesser curvature of the stomach. A 1 x 1.7cm node posterior to the lesser curvature of the stomach is seen. The left lobe of the liver demonstrates a zone of low attenuation in the region of the radiation port. An accessory spleen is noted. 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). The effects of radiation on the liver may be seen within weeks. A zone of low attenuation within the radiation port develops due to fatty infiltration. Over time, the irradiated area becomes atrophic.