The histopathology and ultrastructure of liver disease in erythropoietic protoporphyria

Abstract
The light, polarization and EM changes in the liver of 4 [human] cases of erythropoietic protoporphyria (EPP) are described. In 1 of these cases liver involvement resulted in death, whereas in the other 3 there were no symptoms referable to hepatic disease. In 2 cases hepatic pigment was readily visible on light and polarization microscopy and corresponded to characteristic crystalline aggregates seen ultrastructurally. Pronounced micronodular cirrhosis and cholestasis were present in the fatal case, while in the other only mild periportal fibrosis and mononuclear inflammatory cell infiltrate occurred. The 3rd and 4th cases showed no evidence of hepatic involvement on light microscopy. EM revealed characteristic crystal-containing vacuoles indicative of protoporphyrin deposition. The need for early detection of the hepatic lesion is emphasized.