A Case of Epithelioid Leiomyosarcoma of Transverse Colon.

We report here a rare case of epithelioid leiomyosarcoma found in the colon. A 59-year-old male was ad-mitted to our department with a pain in the upper abdomen. Total colonoscopy showed a tumor with ulceration in the transverse colon, and CT scanning demonstrated a large mass with low density areas attaching to thicked great curvature wall of the stomach extending from the body to antrum. He underwent partial resec-tion of the transverse colon and stomach to remove an 8.0×7.5×6.0 cm tumor of the transverse colon, which invaded to the stomach and metastasized to the lymph nodes of the middle colic artery and in the great omen-tum. Histopathological examination of the tumor showed that reticular network was formed by round or polygonal cells with eosinophilic spacious cytoplasm and highly pleomorphilic nuclei. Immunohistologic assess-ment revealed that most of the cells were positively stained for smooth muscle actin, and a diagnosis of epithelioid leiomyosarcoma was made. Surgical removal is selected as the primary treatment of this tumor, but poor prognosis has been reported on this disease, especially the tumor originated from the colon.