BACKGROUND: The potential for malignancy in rectal polyps increases with the size of the polyp, and unexpected malignancy is reported in up to 39 % of large rectal adenomas. Transanal endoscopic microsurgery (TEM) offers the possibility of an en bloc full-thickness excision for lesions in the rectum. We present our results with TEM in the removal of giant polyps equal or greater than 4 cm in diameter.

METHODS: In the period between 1998 and 2012, TEM was performed in 39 patients with rectal polyps measuring at least 4 cm in diameter. Transrectal ultrasound and/or magnetic resonance imaging of the rectum was used when cancer was suspected.

RESULTS: The polyp was removed with en bloc full-thickness excision in 77 % (n = 30). The preoperative diagnosis was benign rectal adenoma in 89.7 % (n = 35). The median size of the polyps was 30 cm(2) (range 16-100 cm(2)). Postoperative complications included bleeding in 4 patients (10.3 %). Histological examination showed unexpected cancer in 4 patients (10.3 %). TEM was curative in 2 of these patients, and the other 2 underwent further surgery. Recurrences occurred in 10 patients (25.6 %) and consisted of 5 adenomas and 5 adenocarcinomas. In 5 patients, these recurrences were treated with endoscopic removal or re-TEM. The remaining 5 underwent total mesorectal excision and/or chemotherapy.

CONCLUSIONS: Full-thickness TEM provides a safe and efficient treatment for excision of giant polyps. In case of unexpected cancer, TEM can be curative. Local recurrence can be often treated with a second TEM procedure.