Microscopic incipient hepatocellular carcinoma found incidentally in a routine liver biopsy specimen

A microscopic atypical focus suggestive of hepatocellular carcinoma is reported. The lesion, 0.3 mm in diameter, was found by chance in a liver biopsy specimen taken from a cirrhotic patient; it was characterized histologically by cytoplasmic basophilia, hypercellularity (high nucleus-to-cell ratio) and microacinar structures. The reticulin framework of the focus was relatively sparse compared with the surrounding noncancerous area. The focus had developed in a regenerative nodule apparently no different from other regenerative nodules of the cirrhosis and showed no accompanying preneoplastic lesion such as adenomatous hyperplasia. A thorough search for the primary lesion, including ultrasonographic imaging and superselective hepatic arteriography, demonstrated no mass lesion in the liver. Therefore, the lesion may have been an incipient de novo hepatocellular carcinoma, and this may be the first report of such a lesion discovered in a biopsy sample.