2010 Volume 52 Issue 5 Pages 1426-1431
During colonoscopy as part of a health check-up, a 50-year-old male patient was diagnosed as having a yellowish white submucosal tumor, about 1 cm in size, with a central depression in the right transverse colon. Endoscopic ultrasonography showed a low echoic heterogeneous tumor in the second and third layers of the colon wall. Because a definitive diagnosis could not be made based on histologic examination of the biopsy specimen, a tentative diagnosis of carcinoid tumor of the transverse colon was made by colonoscopy and endoscopic ultrasonography. Complete resection of the tumor by endoscopic mucosal resection was believed to be difficult, therefore we performed a laparoscopy-assisted transverse colectomy. Macroscopic examination showed a flat submucosal tumor with a central depression, 12 mm in diameter. Histological examination showed hyperplasia of glands with cystic dilatation reversing into the submucosa. No atypical gland was seen, and the lesion was diagnosed to be a hamartomatous inverted polyp. There were no surgical complications and the patient was discharged on the 24th day after the operation. Hamartomatous inverted polyps should be included in the differential diagnosis of colonic submucosal tumors.
