Full-thickness excision using transanal endoscopic microsurgery for treatment of rectal neuroendocrine tumors

To assess the efficacy of full-thickness excision using transanal endoscopic microsurgery (TEM) in the treatment of rectal neuroendocrine tumors.

We analyzed the data of all rectal neuroendocrine tumor patients who underwent local full-thickness excision using TEM between December 2006 and December 2014 at our department. Data collected included patient demographics, tumor characteristics, operative details, postoperative outcomes, pathologic findings, and follow-ups.

Full-thickness excision using TEM was performed as a primary excision (n = 38) or as complete surgery after incomplete resection by endoscopic polypectomy (n = 21). The mean size of a primary tumor was 0.96 ± 0.21 cm, and the mean distance of the tumor from the anal verge was 8.4 ± 1.4 cm. The mean duration of the operation was 57.6 ± 13.7 min, and the mean blood loss was 13.5 ± 6.6 mL. No minor morbidities, transient fecal incontinence, or wound dehiscence was found. Histopathologically, all tumors showed typical histology without lymphatic or vessel infiltration, and both deep and lateral surgical margins were completely free of tumors. Among 21 cases of complete surgery after endoscopic polypectomy, 9 were histologically shown to have a residual tumor in the specimens obtained by TEM. No additional radical surgery was performed. No recurrence was noted during the median of 3 years' follow-up.

Full-thickness excision using TEM could be a first surgical option for complete removal of upper small rectal neuroendocrine tumors.