Early invasive colorectal carcinomas with submucosal invasion: radiographic characteristics with barium double contrast images.
BACKGROUND
We assessed the radiographic characteristics of early colorectal carcinomas with submucosal invasion (CCSI) with the use of double-contrast images.


METHODS
From 1989 to 1997, 193 patients with 196 CCSI lesions underwent double-contrast barium enema examinations. Three gastrointestinal radiologists retrospectively reviewed the radiographic characteristics of the lesions and classified them as protruding and depressed types by consensus. Further, subclassifying the protruding into lobular and smooth types was accomplished on the basis of surface structure. Each type was compared with pathologic findings of resected specimens.


RESULTS
The incidence of the protruding type was 98.0%, and that of the depressed type was only 2.0%. The proportion of smooth lesions was 49.0% for the protruding type; these had a mean diameter of 17.9 mm, which was significantly smaller than the 23.1 mm mean observed for lobular lesions (p < 0.01). Of the smooth lesions, 44.7% demonstrated massive invasion, whereas 91.8% of lobular lesions exhibited only slight or moderate invasion into the submucosa (p < 0.01). The extent of invasion of the smooth lesions was greater than that for their lobular counterparts in terms of venous and lymph node involvement.


CONCLUSIONS
Almost all CCSIs could be identified radiologically as protruding lesions; these had a smooth rather than a lobulated surface and demonstrated greater malignancy, despite the smaller size. It is clinically important to discriminate these from other polypoid lesions in establishing patient treatment. Double-contrast imaging is useful for evaluation of the surface characteristics of CCSIs in barium enema studies.
Department of Diagnostic Radiology, National Cancer Center Hospital, 1-1Tsukiji 5-chome, Chuo-ku, Tokyo, Japan 104-0045.
G
G
Iinuma
N
N
Moriyama
K
K
Miyakawa
N
N
Yamamoto
T
T
Fujii
T
T
Shimoda
T
T
Ishikawa
K
K
Ushio
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology; D001466:Barium Sulfate; D003106:Colon / Q000000981:diagnostic imaging / Q000473:pathology; D012809:Colon, Sigmoid / Q000000981:diagnostic imaging / Q000473:pathology; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D004733:Enema; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000000981:diagnostic imaging / Q000473:pathology; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011859:Radiography; D012007:Rectum / Q000000981:diagnostic imaging / Q000473:pathology; D012811:Sigmoid Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D013499:Surface Properties
D003287:Contrast Media; D001466:Barium Sulfate