Polyphasic type A hepatitis: histological features.

The histology of polyphasic type A hepatitis was analyzed in liver biopsy specimens of two patients. The microscopic examination showed, together with changes of acute viral hepatitis, portal plasma cell infiltration, limiting plate erosion and porto-portal bridging necrosis. These features, although sometimes described in classical HAV hepatitis, appear to be similar to those commonly observed in severe and evolving forms of acute hepatitis due to other hepatotropic viruses. Only careful serological analyses can lead to a correct diagnosis and prognosis in case of polyphasic type A hepatitis.