Aggressive Desmoplastic Small Round Cell Tumor in an Adult: A Case Report and Literature Review.

Desmoplastic small round cell tumor (DSRCT) is a rare and highly aggressive sarcoma that predominantly affects adolescents and young adults. It is defined by a characteristic chromosomal translocation, t(11;22) (p13;q12), resulting in the EWS-WT1 fusion gene. Owing to its rarity and aggressive behavior, optimal treatment strategies remain poorly established. We report the case of a 35-year-old male who presented with progressive abdominal pain, bloating, and early satiety. Imaging revealed an intra-abdominal mass, and histopathological evaluation with immunohistochemistry confirmed the diagnosis of DSRCT. Molecular confirmation of the EWS-WT1 fusion was not performed. The patient underwent cytoreductive surgery followed by early postoperative intraperitoneal chemotherapy (EPIC) and intensive systemic chemotherapy. Although initial disease control was achieved, the patient subsequently developed peritoneal recurrence and isolated liver metastasis requiring multiple lines of salvage chemotherapy and liver metastasectomy. Despite aggressive multimodal management, the disease demonstrated progressive chemoresistance. DSRCT is characterized by an aggressive clinical course with a high risk of recurrence and distant metastasis. This case is distinguished by adult age at presentation, the use of EPIC combined with systemic therapy, liver metastasectomy, and a relatively prolonged survival compared with historical series. It highlights the limitations of current treatment strategies and the urgent need for novel systemic and targeted therapies in DSRCT.