Transanal local excision in the treatment of rectal carcinoid: results and implications

For rectal carcinoid tumors smaller than 10mm in diameter, local excision is thought to be an appropriate treatment. On the other hand, the biological behavior of tumors measuring 10 to 20mm is unpredictable. In this study our goal was to assess the validity of transanal excision in the treatment of rectal carcinoid tumors.

We identified 18 rectal carcinoid cases that underwent transanal excision. These patients' clinical data were reviewed retrospectively for details of age, gender, tumor location, lesion size, recurrence at follow-up assessment and histopathological findings.

Patients were divided based on tumor size (<10, 10-15mm) and then analyzed for clinical and pathological factors. Of the 18 tumors, 9 were smaller than 10mm. Of patients with tumors <10mm, 1 patient had invasion into the muscularis propria. Of patients with tumors 10-15mm, 3 tumors had invaded the muscularis propria and lymphovascular invasion was seen in 2 tumors. No patient showed recurrence or tumor-related mortality.

Our results suggest that transanal local excision against smaller rectal carcinoids (<15mm) is effective in the treatment of rectal carcinoid tumors. To achieve disease clearance, local excision should be performed even in the case of small rectal carcinoid tumors. Our strategy for treating rectal carcinoid tumors with lesions smaller than 15mm with initial local resection to assess histopathological findings is thought to be an appropriate treatment.