Bj. Rembacken et al., Flat and depressed colonic neoplasms: a prospective study of 1000 colonoscopies in the UK, LANCET, 355(9211), 2000, pp. 1211-1214
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
General & Internal Medicine","Medical Research General Topics
Background Flat and depressed colorectal tumours were originally thought to
be unique to the Japanese population. Recently there have been reports of
flat and depressed lesions in western countries but they have been thought
to be uncommon.
Methods In this prospective study, 1000 consecutive patients attending for
routine colonoscopy were examined for flat or depressed lesions. The examin
ations were done by one European colonoscopist using methods developed in J
apan.
Finding 321 adenomas were found: 202 (63%) were polypoid, 36% (117) were fl
at and 2 (0.6%) appeared depressed. Most adenomas contained areas of mild o
r moderate dysplasia but 10% (31) were severely dysplastic. Six Dukes' A ad
enocarcinomas were identified together with 25 more advanced adenocarcinoma
s. The likelihood of Dukes' A cancer or severe dysplasia increased from 4%
(3/70) in small flat lesions, to 6% (9/154) in small polyps, 16% (8/50) in
larger polyps, 29% (14/49) in large flat lesions, and 75% (3/4) in depresse
d lesions. 54% (20/37) lesions containing severe dysplasia or Dukes' A carc
inoma were flat or depressed.
Interpretation The polyp-carcinoma hypothesis prompts colonoscopists to sea
rch only for polypoid lesions when screening for cancer, and many early col
orectal neoplasms may therefore be missed. Colonoscopists require training
in the recognition of flat and depressed lesions to detect colorectal tumou
rs in the early stages.