OBJECTIVETo recognize the characteristics of desmoplastic small round cell tumor (DSRCT) and improve the standard of diagnosis.

METHODSWe retrospectively reviewed the clinical data on the treatment of 2 patients with DSRCT in terms of their conditions, tissue sources, pathologic characteristics, immunohistochemical methods, clinical manifestation, diagnosis, treatment and prognosis.

RESULTSClinical manifestations were complicated. The 2 patients were mis diagnosed before operation. Their tumors consisted of irregular nests of small and round cells, with nuclear hyperchromatism and scant cytoplasm embedded in a plenty of fibrous connective tissues. The edge of the nest was clear, with different sizes and shapes. Immunohistochemically, the 2 patients were positive for CK or EMA, NSE, des and vim of the epithelium, nerve, muscle and interstitial. They died 9 months after operation.

CONCLUSIONSThe tumor may occur in the abdomen, pelvic cavity and other sites, with different clinical manifestations. Routine examination should be replaced by immunohistochemical test for correct diagnosis of the tumor. Prognosis of most patients is not good.