CT findings of regression in intraabdominal desmoplastic small-cell tumor.

We report the computed tomographic (CT) findings in a patient with intraabdominal desmoplastic small-cell tumor before and after 10 weeks of chemotherapy. This tumor is a rare, frequently fatal neoplasm of the peritoneum, seen predominantly in young males. Initial CT demonstrated large intraperitoneal masses, hepatic metastases, retroperitoneal and right axillary lymphadenopathy, ascites, and pleural effusion. Follow-up CT showed marked decrease of the main tumor bulk and complete regression in the axillary nodes.