Abstract

Dysplastic nodule (DN) is considered as precancerous lesion of hepatocellular carcinoma (HCC). There are several evidences to support the theory about multistep progression of hepatocarcinogenesis. Recently we experienced a patient with HCC of the odule-in-nodule pattern, namely small HCC within DN, which supported the multistep theory of hepatocarcinogenesis. The tumor was seen as a 3 cm, arterial enhancing mass with delayed wash-out patterns in the segment Ⅶ at helical CT. The patient was treated by surgical resection. A 3.0×2.5 cm mass was seen in the resected specimen. A 2.2×1.5 cm, smaller nodule was observed within this mass, i.e. the odule-in-nodule pattern. Microscopically, various grades of HCC foci were seen within high grade DN. Because DN does not always progress to HCC, further studies are needed to evaluate what kind of DN has the high possibility of progressing of HCC at last.

• Keywords: Dysplastic nodule;Small hepatocellular carcinoma;Carcinogenesis