Endoscopic submucosal dissection for rectal carcinoid tumors.

Background: Endoscopic submucosal dissection (ESD) has an advantage over endoscopic mucosa resection (EMR) by enabling removal of gastrointestinal neoplasms en bloc. The ESD procedure is the treatment of choice for rectal carcinoids that have classic histologic architecture with minimal cellular pleomorphism and sparse mitoses, but it has not been applied for such tumors.

Methods: The ESD procedure was performed for patients with colorectal tumors that fulfilled the inclusion criteria specifying tumor with a diameter of 10 mm or less, no muscular layer invasion, and no metastases to the lymph nodes or distal organs. The ESD procedure was performed for patients with rectal carcinoids but no node or distal metastasis.

Results: This study enrolled 20 rectal carcinoid tumors from 20 consecutive patients. The mean tumor size was 7.6 mm (range, 3-16 mm). En bloc removal was achieved for all the tumors, and the complete resection (en bloc with tumor-free lateral/basal margins) rate was 90% (18/20). The two cases in which the margins were not evaluable due to burn effects still are free of recurrence and metastasis at this writing. Perforation was seen in one case, which was managed nonsurgically.

Conclusions: Precise histolopathogic assessment of the specimens resected en bloc by ESD may reduce tumor recurrence and metastasis after ESD. As the treatment of choice for small rectal carcinoids, ESD is associated with nominal risks of metastatic disease.