The pathology of colorectal polyps and cancers

Colorectal neoplasia is amongst the most common cancers in women and men. In the UK, the NHS Bowel Cancer Screening Programme has been established for the early detection of the precursor lesions of colorectal cancers. Endoscopic screening, surveillance and provision of biopsies for histological assessment are the basis for ensuring the diagnosis of a lesion and for informing research regarding epidemiology, biology and evidence-based management. A wide variety of pathological entities may be encountered at endoscopy which may present as a polyp. Amongst others, classical adenomas, serrated adenomas, inflammatory lesions, hamartomas and non-epithelial neoplasms all occur. Understanding the detailed histological layout of the large intestine is important for ensuring understanding of histopathological classifications which now go beyond the classical Dukes and TNM (tumour, node, metastasis) systems. Recently, the molecular biological properties of colorectal neoplasia have become better understood. Five major categories of genetic abnormality have recently been described which correlate with the morphology of the respective entity. The clinical management of a colorectal lesion nowadays comprises a multidisciplinary approach to diagnosis and treatment. It is vital that everyone persistently strives for good communication among gastroenterologists, endoscopists, histopathologists, surgeons and radiologists so that the establishment of management protocols is ensured in order to achieve optimal patient outcome.