Figure 2c: Patient 2. Contrast-enhanced transverse CT scans in 48-year-old man with no known history of acute leukemia who presented with diffuse abdominal pain. (a) Initial CT scan shows a mass (arrow) and tumor infiltration of the mesentery. A mesenteric vessel (arrowhead) is situated within the mass. An intraluminal polypoid mass of high attenuation (not shown) was noted in the ileum. Exploratory laparotomy was performed for obstructive symptoms, and open lesion biopsy enabled diagnosis of granulocytic sarcoma. (b, c) Follow-up scans obtained 1 month later show large amount of ascites with enhancement of the peritoneum (black arrowheads in b), diffuse bowel wall thickening (white arrowhead in b), infiltration of the mesentery, and rapid interval development of diffuse mesenteric infiltration by soft tissue (arrowheads in c). (d, e) Second set of follow-up scans obtained 1 month after b and c, after chemotherapy, shows marked reduction of tumor dissemination with substantial resolution of ascites, infiltration of bowel wall and mesentery, and the tumor mass, which had once largely occupied the pelvic cavity. There remains some thickening of the bowel (arrowheads) and residual infiltration of the mesentery.