Leiomyosarcoma of colon: report of two cases.

Leiomyosarcoma of the colon is a rare tumor, with fewer than 45 cases being reported by 1980. Wide resection, 10 cm margin, and adjacent mesentery will decrease chances of locoregional relapse. We recently encountered two leiomyosarcomas in the colon in the past two years. One is a 63-year-old female who was seen with rectal bleeding, pain, and was found to have a large intraluminal leiomyosarcoma in the descending colon. Biopsy revealed leiomyosarcoma, grade III. She underwent a wide subtotal colectomy with ileosigmoid anastomosis, with metastases to three of the nodes in the mesentery, and remains well. The second is a 69-year-old female with general weakness who had previously undergone a hysterectomy and cholecystectomy. On examination she was found to have an abdominal mass. This proved to be a large leiomyosarcoma arising in the proximal portion of the transverse colon. There were no metastatic areas to the liver, chest, or any other areas. She has undergone extended right colectomy and remains well. Because of the rarity of this type of cancer, there is no established protocol concerning its treatment.