Hepatocellular carcinoma (HCC) frequently occurs in association with liver cirrhosis, as chronic liver
disease is one of the most important factors in carcinogenesis. In addition to HCCs, recent reports of
pathologic studies of resected specimens from cirrhotic liver describe associated small nodular lesions
such as regenerative nodule, dysplastic nodule (adenomatous hyperplasia), and dysplastic nodule with
subfocus of HCC (early HCC). In hepatocarcinogenesis of the cirrhotic liver, a regenerative nodule
might be the first step in the development of HCC, going through phases of dysplastic nodule, early
HCC and early advanced HCC in a multistep fashion. Fortunately, recent advances in various imaging
techniques have facilitated the verification of these nodules. In this review, new nomenclature of
small hepatocellular nodules, and detection and characterization of hepatic nodules in carcinogenesis
with various imaging techniques are described with focus on the premalignant lesions and early stage
of HCC. In addition, the efficacy of various imaging techniques for diagnosing them is discussed.
Although the terms and definitions of these nodules are still variable and controversial, familiarity
with the concept of these borderline lesions is important.
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