Desmoplastic Small Round Cell Tumor

Desmoplastic small round cell tumor (DSRCT) is a relatively recently identified, rare, aggressive cancer that arises from the peritoneal lining of the abdominal cavity and predominantly affects male adolescents and young adults. DSRCT is included in the Ewing family of tumors and harbors a unique translocation between EWSR and WT1 genes. Patients characteristically present with advanced disease, including widespread involvement of the abdominal cavity and pelvis, with frequent extraperitoneal metastases involving liver, spleen, and thoracic lymph nodes. Five-year overall survival remains approximately 15 to 20% in recent series despite aggressive multimodal therapy. Neoadjuvant chemotherapy, complete resection, defined as less than 1 cm3 of residual tumor, and consolidative whole abdominopelvic radiotherapy (WAP-RT) appear to play important role in curative treatment. The rarity of DSRCT makes large randomized trials difficult and consensus statements about clinical approach impossible. However, this chapter summarizes the best available data on the pathogenesis, diagnosis, and treatment of DSRCT; highlights the major advances made in these areas; and discusses the addition of local therapy to the treatment paradigm. This review contains 3 figures, 1 table, and 51 references.   Key Words: DSRCT, peritoneal malignancy, desmoplastic round cell tumor, surface malignancies of the peritoneum, desmoplastic small round cell tumor of the abdomen, surgical oncology, rare malignancies, surgical therapy of abdominal malignancies