Should all endoscopically excised rectal polyps be tattooed? A plea for localization.

Background: More than 5-8 % of endoscopically removed rectal polyps presumed to be benign contain invasive carcinoma. Tattooing has been advocated for follow-up localization of the resection site. Despite proven benefits, the authors propose that tattooing is not routinely performed when benign-appearing rectal polyps are endoscopically excised, thereby confounding management when invasive cancer is found. The secondary goal of the study was to determine the frequency of localization, polyp characteristics, and accuracy of predicting malignant potential at the authors' institution.

Methods: All patients with rectal neoplasia discovered during endoscopic polypectomy from 1 January 2003 to 1 August 2010 were retrospectively identified from Temple University Hospital's Tumor Registry. Demographic and clinical data were extracted from medical records including polyp size, gross appearance, pathology, resection margins, location based on preoperative colonoscopy, initial removal technique, tattoo performance, and ensuing procedures.

Results: During the study period, 49 patients had colonoscopic excision of presumed benign rectal polyps with ensuing diagnosis of neoplasia in the specimen. The malignant histology included adenocarcinoma (n = 5), carcinoma in situ (n = 21), carcinoid (n = 22), and composite carcinoid (n = 1). Only two polyps were tattooed at the initial polypectomy. Three polyps were "suspicious for malignancy." None of the suspicious polyps were tattooed. One of the suspicious lesions was an adenocarcinoma, and the remaining two were benign. The distance from the anal verge was noted in only seven patients. The predominant excision technique was hot snare polypectomy (n = 29). None of the incomplete polyp excisions for 15 patients were "suspicious for malignancy" or tattooed. Several strategies were used to manage incomplete resections including surveillance (40 %), repeat colonoscopic polypectomy (27 %), and surgery (33 %).

Conclusions: Most malignant rectal polyps are neither diagnosed nor tattooed at initial colonoscopy. Moreover, the distance of the polyp from the anal verge is rarely measured, and gross characteristics are not well described. Tattooing of all endoscopically excised rectal polypectomy sites would avoid confounding of subsequent identification and management.