In this paper two cases of colonic lipoma are reported, which is relatively rare disease having been reported only 30 cases in Japan.
Case 1. A man aged 75 year-old was sent to our clinic with the complaints of persistent constipation and abdominal tenderness. With barium enema a globar, sessile and clearly bordered tumor shadow in the sigmoid colon was demonstrated, and the border of the defect was smooth so was diagnosed a benign tumor radiographically. Endoscopically, the tumor had smooth and yellowish red mucosal surface suggesting a submucosal tumor. The operated specimen showed a sessile, semiglobar tumor (3.5 × 3.0 × 3.0 cm) with no ulceration ; on the mucosa. Cut surface of the tumor was yellowish and we diagnosed a lipoma histologically.
Case 2. A 56 year-old woman with left lower abdominal pain was hospitalized. Barium enema showed in the descending colon a globar, sessile and clearly defined tumor shadow of which surface was smooth and not ulcerative. Endoscopically, the tumor was covered with almost normal mucosa but had shallow ulceration and erosion on the central mucosa. Clinically we diagnosed a submucosal tumor and suspected it of leiomyoma, but biopsy specimen showed normal. Operated specimen was a sessile, semiglobar tumor with ulceration having surrounding erosion on the central mucosa of the tumor. Histologically fatty tissue developed expansively between muscle layers and no malignant findings were not recognized.