Partial nodular transformation in a cirrhotic liver

We present a case of partial nodular transformation (PNT) of the liver in a 57-year-old man with a history of heavy drinking. On computed tomography, a low-density mass, measuring 3 cm in diameter, and associated with portal flow defect was visualized. Based on this finding and on the findings of other imaging studies, hepatic resection was performed because of suspected hepatocellular carcinoma. Pathology examination of the excised specimen showed small portal tracts in the lesion. The findings for the rest of the liver were suggestive of mild liver cirrhosis. While PNT is similar to nodular regenerative hyperplasia (NRH), in NRH there is diffuse nodular transformation of the whole liver, whereas in PNT only the area adjacent to the porta hepatis is affected. The portal flow defect in PNT may be the result of attenuation of the portal tracts in the lesion. This case is of interest because there was only one PNT lesion, rather than multiple lesions, and because it occurred in a cirrhotic liver, thus giving rise to the suspicion of hepatocellular carcinoma. PNT is a benign disorder, thus it is essential to establish a definitive diagnosis by imaging and ultrasound-guided histological biopsy to prevent unnecessary hepatic resection.