Amiodarone-associated phospholipidosis and fibrosis of the liver. Light, immunohistochemical, and electron microscopic studies.

The hepatic morphological findings in 3 patients treated with amiodarone, a potent and effective antiarrhythmic drug, are reported. An enlarged liver and mild elevation of hepatic enzymes were the most important clinical findings. Fibrosis, cholangitis, mixed inflammatory infiltrate, and cytoplasmic granularity of the hepatocytes were the main histologic changes common to all cases. In 2 of the cases the presence of Mallory bodies was confirmed by electron microscopy. In 1 of these 2 cases, Mallory bodies were also confirmed by immunostaining. Ultrastructurally, numerous cytoplasmic inclusions with a membranous or lamellar structure identical to those described in phospholipidosis were the most striking features seen in hepatocytes, biliary epithelial cells, Kupffer cells, and endothelial cells.