ABSTRACT
Colorectal biopsies form a significant proportion of the work of most departments of diagnostic histopathology. Colorectal diseases are common, carcinoma of the large bowel, for example, being the second most frequent malignant neoplasm to cause death in developed countries (Office of Population, Censuses and Surveys, 2003; World Health Organization, 1995). Rectal biopsy has always been a highly cost-effective and non-invasive investigation, but since the introduction of flexible fibre-optic colonoscopy and sigmoidoscopy and subsequent digital and other technologies (Saunders, 2005; Brown and Saunders, 2005) the scope of biopsy diagnosis of large bowel diseases has greatly increased. It is now a routine matter to examine and biopsy the terminal ileum. This has led to an acceleration in the rate of advance in our understanding of these diseases and the development of new forms of treatment. The range of diagnostic material now presented to the pathologist reflects these developments and demands a wide knowledge of the tissue changes in interpreting ever-smaller biopsy samples. These changes are described and illustrated in subsequent chapters, but in their interpretation the clinician and pathologist must appreciate each other’s roles.
