Histopathological work-up of resection specimens, local excisions and biopsies in colorectal cancer.

The pathological examination of material removed from patients with colorectal neoplasia is important. It provides a wide range of information on, for example, the quality and completeness of excision, the stage and biological aggressiveness, the need for further therapy, and response to therapy. Molecular testing adds valuable information on genetic risk and is required before treatment with anti-EGF-r antibodies. This article highlights the value derived from macroscopic inspection of surgical specimens, careful microscopy and excellent reporting according to national guidelines. Increasing use of a number of preoperative therapies and combinations in rectal cancer change the pathological features found and a standardised approach to the diagnosis of complete response is required. It touches upon the issues with frequent changes in TNM staging and the difficulties these changes are causing. The widespread introduction of bowel cancer screening is changing the stage of presentation of colorectal cancer leading to increasing numbers of local excisions and polyp cancers.