Small hepatocellular carcinomas undetected on two-phased incremental computed tomography. Angiographic and clinicopathologic findings.
OBJECTIVE
To elucidate the characteristic clinicopathologic features of hepatocellular carcinomas (HCCs) undetected on two-phased incremental computed tomography (CT).


METHODS
Computed tomographic scans of 115 surgically resected small (< or = 3 cm) HCCs from 83 patients were performed 45 seconds and 6 minutes after the administration of contrast material. These scans were compared with corresponding angiographic and histopathologic findings.


RESULTS
Eighty HCCs (70%) were depicted on the early images; 73 (63%) on the delayed images; and 89 (77%) using two-phased incremental CT. The small HCCs undetected on the early images but seen histologically had the following characteristics: (1) absence of a fibrous capsule, (2) well-differentiated tumor, (3) replacing growth patterns of the tumors, (4) lack of fatty metamorphosis and/or clear cell changes, (5) hypovascular on angiography. Those not seen on delayed images had the following characteristics: (1) absence of a fibrous capsule, (2) replacing growth patterns, and (3) presence of portal tracts in the tumors.


CONCLUSIONS
The replacing growth pattern and the presence of portal tracts correlate with the undetectability on CT. For HCCs undetected on CT, treatment methods must be considered carefully, because the HCCs may be receiving transsinusoidal and portal blood supplies.
Honda
H
H
Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Kaneko
K
K
Maeda
T
T
Kuroiwa
T
T
Fukuya
T
T
Yoshimitsu
K
K
Irie
H
H
Aibe
H
H
Takenaka
K
K
Tsuneyoshi
M
M
D000328:Adult; D000368:Aged; D000792:Angiography / Q000379:methods*; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D003287:Contrast Media; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D008113:Liver Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media