Colonic Leiomyosarcoma Treated With Laparoscopy-Endoscopy Cooperative Surgery for Colorectal Tumors (LECS-CR) Resulting in Peritoneal Dissemination Recurrence: A Case Report.

Gastrointestinal leiomyosarcoma is a rare tumor, particularly in the colon. We report a case of colonic leiomyosarcoma treated with laparoscopy-endoscopy cooperative surgery for colorectal tumors (LECS-CR) and discuss its feasibility and limitations. A 57-year-old man presented with a submucosal tumor in the ascending colon detected following a positive fecal occult blood test. LECS-CR was performed for both diagnostic and therapeutic purposes. Histopathological examination confirmed leiomyosarcoma. Although complete resection was achieved, peritoneal dissemination recurrence at the anastomotic site was observed one year postoperatively, requiring open right hemicolectomy. No recurrence has been observed during the six months following the second surgery. While LECS-CR may represent a minimally invasive treatment option, strategies to prevent tumor dissemination associated with bowel opening procedures remain a critical issue. This case highlights the potential limitations of LECS-CR in leiomyosarcoma and underscores the importance of appropriate patient selection and postoperative surveillance strategies.