CYFRA 21-1 is a fragment of cytokeratin 19 (CK 19). Four patients with
large intrahepatic (orperipheral) cholangiocarcinoma (CC) and high se
rum levels of CYFRA 21-1 (normal, less than or equal to 2 ng/ml) are r
eported. CYFRA 21-1 levels exceeded 9 ng/ml in all 4 patients. Carcino
embryonic antigen (CEA), was high in 1 (CEA; normal range, less than o
r equal to 5.0 ng/ml) and carbohydrate antigen 19-9 (CA 19-9) was high
in 3 (CA19-9; normal range, less than or equal to 36 U/ml). We also m
easured serum levels of CYFRA 21-1 in 13 patients with hepatocellular
carcinoma (HCC) more than 5 cm in diameter. Levels of CYFRA 21-1 excee
ded 2 ng/ml in 9 of the HCC patients and were higher than 9 ng/ml in 2
of the HCC patients. Levels of alpha fetoprotein (AFP) and/or protein
induced by vitamin K absence or antagonist II (PIVKA II) were elevate
d in all HCC patients (AFP, PIVKA II, respectively; normal range, less
than or equal to 10.0 ng/ml and less than or equal to 0.1 AU/ml) CYFR
A 21-1 levels were measured twice or three times during the clinical c
ourse in 2 CC patients and in 6 HCC patients, and increased gradually
with tumor growth in the 2 CC patients and in 3 of the 6 HCC patients.
Marked increases in serum CYFRA 21-1 levels in patients with large li
ver cancers, particularly in those with normal levels of AFP and PIVKA
II, would suggest the existence of intrahepatic CC rather than HCC.