Small liver masses in cirrhotic patients. A pathological clue for the morphogenesis of human hepatocellular carcinoma.

Eleven small primary liver lesions detected in four cirrhotic patients are reported in detail. Some lesions showed the histopathological features of macroregenerative nodules (MRN) containing foci of cellular and structural atypia or of hepatocellular carcinoma (HCC). Other lesions showed the histological abnormalities of the early developmental stage of HCC without a background of MRN. Finally one lesion is described with an equivocal background between benign and malignant, containing a focus of carcinoma. All lesions presented suggest the presence of different pathways in the morphogenesis of human HCC.