Lipomatous polyposis of the colon

Intramucosal fat is uncommon in large bowel polyps but raises three differential diagnoses

AIMS

This case series intends to expand currently limited knowledge regarding the existence and diagnostic significance of intramucosal fat in colorectal polyps.

METHODS

Clinicopathological features of nine such polyps were reported following histopathological review, including S100 and EMA immunohistochemistry.

RESULTS AND CONCLUSIONS

Such review subdivided seven polyps into three groups: (1) mucosal perineurioma/serrated polyps with fat among the perineurial stroma (three cases); (2) submucosal lipomas with adipose tissue extending into the overlying mucosa (two cases) and (3) polyps with intramucosal adipose tissue only, that is, the newly described but less-recognised entity known as intramucosal lipoma (two cases). The two remaining polyps of this series did not include submucosa but, from assessing their muscularis mucosae, were favoured to represent intramucosal lipomas. The first two phenomena are formally described for the first time by this case series. The last of these three diagnoses should prompt investigations for Cowden syndrome, but intramucosal lipomas are more often sporadic/non-syndromic.

Mesenchymal Tumors of the Gastrointestinal Tract Other than GIST

Mesenchymal tumors involve the gastrointestinal (GI) tract more frequently than other visceral organs. Many such tumors are small, and are benign and increasingly being detected incidentally during colonoscopic screening. Some tumors show distinctive features at this site, such as schwannoma and clear cell sarcoma-like tumor of the GI tract. Without knowledge of these features, recognition of these tumor types can be difficult. This reviews addresses recent developments and diagnostic features of mesenchymal tumors of the GI tract other than gastrointestinal stromal tumor (GIST).

[Lipomatous polyposis of the colon: a case report]

Lipomatous polyposis of the colon is a rare affection, with about 10 published cases. This affection is characterized by a great number of polyps which can reach several hundreds, of diffuse location on the entire length of the colon, with a higher density on the left colon and the sigmoid. The size of polyps varies from 1 to 10 cm. When they are voluminous, they can be cause of obstruction, ulceration or bleeding. We report a case of colonic lipomatous polyposis, associated with an ileocolic lipomatous, an ileocolic diverticulosis and adenomatous polyps in a 70-year-old man.