Nodular regenerative hyperplasia of the liver associated with polyarteritis nodosa.

Nodular regenerative hyperplasia (NRH) of the liver was found at autopsy in a 74-year-old woman with generalized polyarteritis nodosa. Such an association is very rare. Small hepatic arteries displayed necrotizing angiitis with thrombotic occlusion of parallel-running portal veins in the portal tracts. Sinusoidal dilatations with an atrophy and occasional dropout of the hepatocytes were often found in the extranodular parenchyma around and between the hyperplastic nodules of hepatocytes. The arterial, portal venous, and sinusoidal lesions of the liver were prominent in the present case, and all might be contributing factors for the development of NRH of the liver.