# Multiple Desmoplastic Small Round Cell Tumor in the Intestine: A Case Report

## TL;DR

This case report describes a rare desmoplastic small round cell tumor in the intestine of a 38-year-old male, diagnosed after surgery and confirmed through histopathology and genetic analysis.

## Contribution

The paper presents a rare clinical case of DSRCT in the intestine, emphasizing the need for more case reports to improve treatment strategies.

## Key findings

- The patient had multiple tumors in the descending and sigmoid colon with peritoneal dissemination.
- Histopathology and genetic analysis confirmed the diagnosis of desmoplastic small round cell tumor.
- The patient underwent successful surgery and will continue chemotherapy.

## Abstract

Desmoplastic small round cell tumor (DSRCT) is a highly malignant sarcoma and an extremely rare tumor, predominantly found in the abdominal and pelvic regions. Here, we report the case of a patient who underwent surgical treatment for multiple desmoplastic round cell tumor in the intestine.

A 38-year-old male patient visited our hospital after a health check revealed positive occult blood in his stool and a colonoscopy revealed tumors in descending colon and sigmoid colon. Biopsy results revealed poorly differentiated adenocarcinoma. Chest and abdominal enhanced computed tomography revealed 3 tumors from descending colon to sigmoid colon and numerous peritoneal disseminations. Based on these findings, we diagnosed multiple colon cancers and performed a laparoscopic left hemicolectomy. Hematoxylin–Eosin (H&E) staining showed that in all tumors, atypical cells with large and small swollen nuclei formed irregular solid nests of various sizes against a background of extensive desmoplastic or myxomatous stroma. Immunohistochemistry showed that tumor cells were AE1/3 (+), S-100 (–), Desmin (–), WT1 (–). Genetic analysis detected the Ewing’s sarcoma and Wilms tumor fusion gene at another inspection agency. Histopathological examination identified desmoplastic small round cell tumor. The patient was discharged on the 19th postoperative day without postoperative complications. He will undergo chemotherapy at another hospital.

We experienced a very rare case of DSRCT. DSRCT is a fatal disease that primarily affects adolescent and young adult males. Currently, there is no proven treatment. More case reports are essential to improve management of this disease.