Liver nodules resembling focal nodular hyperplasia

Clinicopathological features of nine cases of non-cirrhotic portal hypertension: current definitions and criteria are inadequate

AIMS

The clinicopathological features of nine patients with non-cirrhotic portal hypertension were studied and an attempt was made to apply the descriptive criteria of experts to the morphological alterations of the livers in order to classify them adequately.

METHODS AND RESULTS

Clinical and biochemical data and the alterations in livers resected at transplantation (n=7) or at autopsy (n=2) were gathered in five males and four females (ages 15-78 years) without aetiological factors for chronic hepatic disease who had oesophageal varices and splenomegaly in the absence of typical cirrhosis. Noting the luminal obstruction of the three hepatic vascular trees, hyperplastic nodule size and distribution, and the density of fibrosis, an attempt was made to assign each case to one of the following diagnostic categories: idiopathic portal hypertension, diffuse nodular regenerative hyperplasia, partial nodular transformation and incomplete septal cirrhosis. When a case could not be categorized into one of these groups, it was listed as non-cirrhotic irregular architectural transformation. Only three cases could be assigned to one pure diagnostic category (two diffuse nodular regenerative hyperplasias and one incomplete septal cirrhosis). Three other cases could not be classified due to the heterogeneity of their lesions. In the remaining three cases, the hepatic morphology was a mixture of hilar partial nodular transformation combined with another abnormal architectural pattern in the peripheral parenchyma: diffuse nodular regenerative hyperplasia in two cases and idiopathic portal hypertension in the other. In seven cases, old thromboses in the hilar portal tree were observed. Stenoses were observed in some of the arterial branches in five cases and in some hepatic venous branches in four. However, no obstructions could be discovered in small or large portal veins in the two classical diffuse nodular regenerative hyperplasia cases.

CONCLUSIONS

The hepatic morphology in this group of non-cirrhotic portal hypertension patients was an abnormal remodelling of the liver associated with the frequent development of irregular hyperplastic nodules and frequent obstructions of the pre- and intrahepatic vascular lumens. It was very difficult to apply the nomenclature proposed by international experts.

Focal nodular hyperplasia-like areas in cirrhosis

AIMS

Focal nodular hyperplasia-like lesions have rarely been described in cirrhotic livers. We describe five cases of such lesions.

METHODS AND RESULTS

Between 1998 and 2001, 146 liver transplants were performed at the Royal Free Hospital for cirrhosis of the liver. Nodular lesions identified in the livers removed at transplantation were defined histologically according to the International Working Party classification (Hepatology 1995; 22; 983). They were present in 63 of these livers, as follows: 36 dysplastic nodules, 121 macroregenerative nodules, and 71 hepatocellular carcinomas. In five patients, an additional 12 nodules (size range 4-23 mm, median 10.5 mm) showed histological features suggestive of focal nodular hyperplasia including mildly inflamed vascular fibrous septa, and ductular proliferation. Pre-transplantation imaging showed features suspicious for hepatocellular carcinoma, in three of these lesions (12, 23 and 23 mm diameter) from two different patients. These lesions were histologically indistinguishable from focal nodular hyperplasia occurring in non-cirrhotic livers, with fibrous scars and septa which contained vascular and ductular structures.

CONCLUSIONS

It is important to recognize that these lesions may occur in the context of cirrhosis and that they should be considered in the differential diagnosis with hepatocellular carcinoma, dysplastic nodules and macroregenerative nodules.