Complete response of giant desmoplastic small round cell tumor treated with chemoradiotherapy: A case report

Abstract

Desmoplastic small round cell tumor (DSRCT) is a rare tumor that mainly affects adolescents, and typically involves the abdominal and pelvic peritoneum. The present study reports one case of giant DSRCT, treated with concurrent chemoradiotherapy, and reviews the available medical literature. A 38-year-old man presented with a 3-month history of pain in the left lower abdomen and nausea, associated with decreased appetite and weight loss. Computed tomography (CT) showed a 12.3×7.9 cm confluent solid mass in the lower abdomen and pelvic cavity. The patient underwent exploratory laparotomy and the final pathological diagnosis was DSRCT. Following laparotomy, the patient was treated with external beam radiotherapy to the whole abdomen and pelvis to a dose of 40 Gy plus a 20 Gy boost to the residual disease. The results indicated that synchronous chemotherapy with cyclophosphamide, adriamycin and cisplatin combined with radiotherapy significantly improved locoregional control of DSRCT and a complete response, as measured by CT assessment 2 months subsequent to radiotherapy. In conclusion, DSRCT is a rare malignancy requiring multidisciplinary treatment, including surgery, chemotherapy and radiotherapy. The results of the present study confirm that radiotherapy has a significant role in the treatment of advanced abdominal DSRCT and may contribute to durable remission.

Keywords: chemotherapy; desmoplastic small round cell tumor; radiotherapy.

Figure 1.

Computed tomography prior to treatment revealed a 12.3×7.9 cm giant confluent solid mass in the (A) upper and (B) lower abdominal cavity with moderate, heterogeneous enhancement, as well as (C) several additional soft-tissue masses in the pelvic cavity. Red outlines indicate the gross tumor volume.

Figure 2.

Hematoxylin and eosin staining of a biopsy specimen from the tumor. (A) Nests of small round cells separated by desmoplastic stroma (magnification, ×200). (B) Certain cells are arranged in well-defined nests, which are delimited by a cellular desmoplastic stroma (magnification, ×400).

Figure 3.

Computed tomography following one month of radiotherapy indicated marked shrinkage of the (A) upper abdominal, (B) lower abdominal and (C) pelvic tumors. Red outlines indicate the gross tumor volume.

Figure 4.

Computed tomography demonstrated complete response of the tumor at 2 months following radiotherapy.