Histological comparison of colon polyps by endoscopic forceps biopsy compared to polypectomy

Kang, Gu Hyum; Huh, Kyu Chan; Kim, Sun Moon; Lee, Tae Hee; Im, Euyi Hyeong; Choi, Young Woo; Kim, Beom Kyoung; Kang, Young Woo; Kang, Gu Hyun

Abstract

BACKGROUND/AIMS: Adenomatous polyps of the colon are believed to be precursor of colon cancer. Total polyp resection is indicated when they are identified. However, resection of the polyp is not always attainable at the initial colonoscopy. The aim of this study was to assess the validity of cold biopsy findings as representative of the whole polypectomy specimen, with regard to the histopathological features.
METHODS
We analyzed 221 patients with colon polyps that were biopsied at their initial colonoscopy and had their adenomas subsequently removed by polypectomy within 2 weeks from the initial procedure. We analyzed the histopathological discrepancies between the cold biopsy and the polypectomy specimens.
RESULTS
We analyzed 302 cases from 221 patients. There was 71.2% agreement between the forceps biopsy and the polypectomy. When colon polyps were diagnosed as carcinoma and villous adenomas, the diagnosis was the same in the polypectomy. Discrepancy between in forceps biopsy with polypectomy was found in the tubular adenomas obtained by forceps biopsy. Fifty tubular adenoma samples obtained by forceps biopsy had a deferent diagnosis than did the polypectomy. Fourteen of 50 tubular adenomas were underestimated by the forceps biopsy samples and seven of the 50 tubular adenomas were finally diagnosed as carcinoma from the polypectomy specimens. Seven villous adenomas were diagnosed as carcinoma and had severe dysplasia (n=4) or 1>=(n=1) size.
CONCLUSIONS
Accurate tissue sampling of colorectal adenomas is crucial for their management. However, forceps biopsy does not accurately reflect the histology of colon polyps. Total resection of colon polyps is needed for an accurate diagnosis.