Intra-abdominal desmoplastic small round cell tumour: multiphase CT findings with histopathologic correlation

Objective To characterize the CT features of desmoplastic small round cell tumor of the abdomen and to correlate them with the histopathologic findings.Methods The spiral CT findings in 4 cases of desmoplastic small round cell tumor proved by immunohistochemical staining were analyzed and compared with pathology retrospectively.Results Multiple large masses in the abdominopelvis were detected in 4 cases,and none of the masses had a definite organ origin.CT showed soft tissue masses with patchy foci of hypodense areas.Contrast-enhanced CT showed mildly or moderately heterogeneous enhancement of the lesions.Other associated findings included calcification(n=2),peritoneal seeding(n = 3),hepatic metastasis(n = 3) and retroperitoneal lymphadenopathy(n = 3),ascites(n=2).Conclusion Intra-abdominal desmoplastic small round cell tumour has certain characteristic on CT scan and enhancement.The diagnosis of desmoplastic small round cell tumor may be suspected in young men with multiple bulky heterogeneous peritoneal soft tissue masses.