Liver cell adenoma in a young man with elevated serum PIVKA-II level.

A 21-year-old man was referred to our hospital because of a liver mass lesion detected by abdominal ultrasonography. He had received no hormonal treatment. Physical examinations revealed no abnormalities, and laboratory data, including hepatic function test results, were within normal ranges, with the exception of elevated levels of serum protein induced by vitamin K absence or antagonist (PIVKA)-II (2.2 AU/ml). Abdominal ultrasonography revealed a hyperechoic mass lesion measuring 10 x 10 cm, with hypoechoic areas located in the right posterior segment of the liver. A low-density area and a hypervascular area were detected in the right posterior segment of the liver by computed tomography and celiac angiography, respectively. As hepatocellular carcinoma could not be completely excluded, the tumor was resected. The tissue consisted of sheets of tumor cells with eosinophilic cytoplasm and round nuclei showing a thin trabecular pattern, and these histological findings indicated liver cell adenoma. After resection of the tumor, serum PIVKA-II returned to the normal level.