Desmoplastic Small Cell Tumor

PURPOSE: Desmoplastic round cell tumor (DSCT) is a highly malignant abdominal tumor first described in 1991, with subsequent cases predominantly noted in pathologic case reports. The authors evaluated response to alternating, intensive chemotherapy in three patients with DSCT, and reviewed the clinical experience with this newly described tumor as reported in the literature. PATIENTS AND METHODS: Three adolescent boys with DSCT were treated intravenously with vincristine 2 mg/m2, doxorubicin 75 mg/m2, cyclophosphamide 1.8 g/m2, alternating with 5-day cycles of etoposide 100 mg/m2/day, ifosfamide 1.8 g/m2/day for a total of 11-15 courses. RESULTS: Each patient showed initial tumor regression during chemotherapy, but developed progressive disease within 8-18 months. One patient subsequently showed a transient response to doxorubicin 45 mg/m2 plus 5-fluorouracil 500-600 mg/m2. All three patients died of disease within 20 months of diagnosis. A comprehensive literature review of clinical data on 101 reported cases of DSCT is presented. The median age was 21 years (range 6-38 years) with 78 male patients and 23 female patients. Ninety-nine cases involved tumor mass in the abdominal-pelvic cavity in proximity to the mesentery. Metastatic seeding to the omentum was most common, followed by spread of disease to liver, distant lymph nodes, lung, and occasionally to scrotum or to ovary. Tumor response to chemotherapy was noted in approximately 50% of 40 patients who received combinations of doxorubicin, cisplatin, cyclophosphamide, etoposide, and/or 5-fluorouracil. Four of 13 patients who received additional radiotherapy were alive at 24-48 months. Median survival was 17 months (range: 3-72 months), with only two patients reported disease free beyond 2 years at 40 and 48 months. CONCLUSION: DSCT should be included in the differential diagnosis of small round cell tumors in children and young adults. Tumor regression has been noted during multiagent chemotherapy, but prolonged survival is rare with current therapies.