Mesenchymal polyps

Most mesenchymal polyps are encountered in the colorectum but some characteristically arise in the oesophagus and stomach. Small bowel polyps are not often sampled but many of the types found in the other locations can be found in the small intestine and are covered elsewhere in this volume. Generally mesenchymal lesions of the tubular gastrointestinal tract that present as polyps are centred in the mucosa or submucosa. However, some lesions that are typically centreed in the muscularis propria are included since they are often confused with superficial lesions. Often the issues in interpreting such lesions revolve around whether the tumour is a gastrointestinal stromal tumour and whether it is a syndromic or sporadic, which has been addressed particularly for neural lesions.