DESMOPLASTIC SMALL-CELL TUMOR - A REPORT OF 3 CASES AND A REVIEW OF THE LITERATURE

Purpose: Desmoplastic round cell tumor (DSCT) is a highly malignant ab dominal tumor first described in 1991, with subsequent cases predomina ntly noted in pathologic case reports. The authors evaluated response to alternating, intensive chemotherapy in three patients with DSCT, an d reviewed the clinical experience with this newly described tumor as reported in the literature. Patients and Methods: Three adolescent boy s with DSCT were treated intravenously with vincristine 2 mg/m(2), dox orubicin 75 mg/m(2), cyclophosphamide 1.8 g/m(2), alternating with 5-d ay cycles of etoposide 100 mg/m(2)/day, ifosfamide 1.8 g/m(2)/day for a total of 11-15 courses. Results: Each patient showed initial tumor r egression during chemotherapy, but developed progressive disease withi n 8-18 months. One patient subsequently showed a transient response to doxorubicin 45 mg/m(2) plus 5-fluorouracil 500-600 mg/m(2). All three patients died of disease within 20 months of diagnosis. A comprehensi ve 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 mal e patients and 23 female patients. Ninety-nine cases involved tumor ma ss in the abdominal-pelvic cavity in proximity to the mesentery. Metas tatic seeding to the omentum was most common, followed by spread of di sease to liver, distant lymph nodes, lung, and occasionally to scrotum or to ovary. Tumor response to chemotherapy was noted in similar to 5 0% of 40 patients who received combinations of doxorubicin, cisplatin, cyclophosphamide, etoposide, and/or 5-fluorouracil. Four of 13 patien ts who received additional radiotherapy were alive at 24-48 months. Me dian survival was 17 months (range: 3-72 months), with only two patien ts reported disease free beyond 2 years at 40 and 48 months. Conclusio n: DSCT should be included in the differential diagnosis of small roun d cell tumors in children and young adults. Tumor regression has been noted during multiagent chemotherapy, but prolonged survival is rare w ith current therapies,