RADIOLOGY: ABDOMEN: Case# 55: MAI C MESSENTERIC MASS/HIV. 42 year old male with AIDS and history of a left lower quadrant mass. A low attenuation fluid collection in the left mesenteric root is seen. It appears well-defined and has a central thick septation through it. It measures approximately 3 x 3 cm. Some adjacent loops of proximal small bowel have minimal wall thickening.