Ten cirrhotic patients with ultrasonically discernible focal liver masses underwent fine cutting needle biopsy. Specimens were obtained from the focal lesions under ultrasound guidance and histologically diagnosed as regenerative nodules. An image analyzer was then used to determine the cytoplasmic area, nuclear area, and nuclear/cytoplasmic ratio for 100 randomly selected cells from each specimen. Data were then compared with data for specimens of normal liver tissue and data from patients with alcoholic or posthepatic cirrhosis or well-differentiated hepatocellular carcinoma (HCC). The morphometric parameters for the group of regenerative nodule specimens fell within an intermediate range between those for HCC and the nondysplastic samples, strongly suggesting a preneoplastic nature. Nine of the 10 regenerative lesions showed liver cell dysplasia, and 3 of these patients developed HCC during follow-up. Ultrasonically discernible focal masses in a cirrhotic liver should be considered preneoplastic, if not neoplastic lesions and treated aggressively to prevent their progression to outright malignancy.