Background: A desmoplastic small round cell tumor (DSRCT) is a rare tumor occuring most frequently in boys during the second decade of life and is localized in the abdominal cavity, usually in the
pelvis minor. At the moment of diagnosis the process is usually considerably advanced with metastases to liver, lungs, bones, peritoneal or pleural wall and the central nervous system. It
is usually impossible to perform primary radical tumor resection and the treatment starts with preliminary polychemotherapy containing, among others, alkylating cytostatic agents. No definite
therapeutic program has been established to date for this type of tumor. Initial chemosensitivity of the tumor has been emphasized; however positive response to chemotherapy
is usually short-lasting. Abdominopelvic radiotherapy should be considered. The prognosis in inoperable cases is still poor.Case Report: A case of a desmoplastic small round cell tumor (DSRCT) in the abdomen of a 16-year-old boy is presented. Diagnostic problems are discussed, focusing on pathomorphological differentation, the clinical course and therapeutic procedures. The primary resistance of DSRCT to polychemotherapy is emphasized with a short lasting partial tumor regression.Conclusions: Poor results of therapeutic methods used so far indicate the necessity of search for the new methods to be used in patients with such tumors.

Keywords: desmoplastic small round cell tumor, treatment difficulties, diagnostic