Figure 3b. Persistent, nonspecific abdominal symptoms in a 23-year-old woman. (a) Initial contrast-enhanced CT scan shows an omental soft-tissue mass (arrowheads) and ascites (arrows). No other masses were present. Desmoplastic small round cell tumor was diagnosed with CT-guided biopsy, and the patient underwent omentectomy and chemotherapy. (b) Contrast-enhanced CT scan obtained 8 months after a shows interval development of diffuse, nodular peritoneal thickening (arrowheads) and mesenteric soft-tissue infiltration (arrow), findings indicative of tumor progression. (c) Contrast-enhanced CT scan obtained 1 month after b shows scalloping of the hepatic capsule from serosal tumor spread (arrowheads) and hematogenous hepatic metastases (straight arrows). A right pleural effusion (curved arrow) is also present.