While adenomatous polyps of the colon have traditionally been thought of as exophytic, polypoid lesions, increasing recognition is being given to a subtype of colonic polyp with only minimal luminal elevation. These 'flat adenomas' are characteristically nonpolypoid, plaque-like elevations, some with a central depression. Substantial reported evidence, mainly from Asian populations, suggests that such lesions have an increased malignant potential despite their relatively small size. The magnitude of risk in Western populations remains controversial. An autosomal dominant syndrome, hereditary flat adenoma syndrome, has been described, with features intermediate between those of familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer. Chromoscopy and high-resolution video endoscopy may be useful diagnostic modalities to detect these lesions in high-risk populations. Endoscopic mucosal resection ('strip biopsy') may be a useful therapeutic technique to remove these flat adenomas. Meticulous colonoscopic examination is prudent policy for all colonoscopists, especially in patients for whom a high index of suspicion exists for these lesions.
|Original language||English (US)|
|Number of pages||7|
|State||Published - Jan 1 1997|
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