A Case of Ascending Colon Liposarcoma Diagnosed after Surgery for Sigmoid Colon Cancer

Liposarcoma is a non-epithelial malignant tumor of soft tissue, which occurs mainly in the retroperitoneum and lower limbs, but rarely in the colon. The present case was a 74-year-old man with no particular complaint, who had undergone surgery for sigmoid colon cancer about a year ago and had no recurrence. One year after the operation, abdominal CT for follow-up showed a submucosal tumor with a contrast effect in the ascending colon. He had no symptoms. Colonoscopy showed no abnormalities. He had no tumors in other sites. The results of the examinations were suggestive of a tumor such as GIST or NEN. The tumor size showed an increasing tendency. Because of these findings we performed laparoscopic ileocecal resection and D2 lymph node dissection. Intraoperative findings showed that the tumor protruded on the serosal side of the ascending colon, but adhesion was not found around it. The pathological findings revealed dedifferentiated liposarcoma of the colon. Liposarcoma of the colon is a rare tumor.