Dysplastic lesions associated with ulcerative colitis may be flat or raised. A raised area of dysplasia (dysplasia associated lesion or mass) may be difficult to distinguish from a sporadic adenoma. Dysplasia in ulcerative colitis is often treated differently than sporadic adenoma.
Alternative expansion for DALM: dysplasia-associated luminal mass
Feature
Sporadic Adenoma
DALM
location
in colon not involved in colitis
in colon involved by colitis
patient
older
younger (< 50 years of age) or long duration of disease
flat dysplasia
absent
may be present or develops during followup
loss of heterozygosity
rare
in 3p and/or p16 on 9p
There may be considerable overlap between sporadic adenomas and DALM. A patient with a DALM lesion may show a relatively benign course after complete removal with a low risk of progression to adenocarcinoma (Odze et al, 1999).
Reasons to treat a polypoid lesion more aggressively:
(1) mass lesion rather than discrete polyp
(2) associated with flat dysplasia
(3) presence of high-grade dysplasia
(4) “not adenoma-like”
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