ACP Best practice no 159. Examination of large intestine resection specimens

Abstract

Macroscopic examination of large intestinal resection specimens by the surgical pathologist provides important diagnostic and prognostic information. This review summarises current recommended protocols and evidence based guidelines for gross description, dissection, and histological block selection in both neoplastic and non-neoplastic colorectal disease. Specific lesions discussed include colorectal cancer, polypectomies and polyposis syndromes, and inflammatory bowel disease. Microscopic examination is briefly described, with emphasis on certain pitfalls that might be encountered in routine practice. A section covering special techniques for the investigation of occult bleeding is included.

Figure 1 Extent of serosal covering of the large intestine. Arrows indicate the "bare" non-peritonealised areas at different levels. (A) The ascending and descending colon are devoid of peritoneum on their posterior surface. (B) The sigmoid colon is completely covered with peritoneum, which extends over the mesentery. (C) The lower rectum lies beneath the pelvic peritoneal reflection. The asterisks in (A) indicate the sites where serosal involvement by tumour is likely to occur.

Figure 2 Sectioning technique for submucosal and full thickness polypectomy specimens.