Abdominal visceral peliosis associated with bacillary angiomatosis. Ultrastructural evidence of endothelial destruction by bacilli.

Peliosis involving solid internal organs is a rare entity, and it has been reported in association with chronic debilitating diseases. Bacillary angiomatosis (BA), on the other hand, is a recently identified lesion found virtually only in individuals infected by the human immunodeficiency virus. We describe herein two cases of visceral BA and peliosis in human immunodeficiency virus-infected patients. Based on light and electron microscopic findings, we conclude that (1) BA bacilli present in the hepatic sinusoidal endothelial cells, in a suitable host milieu, may be the causative agents of peliosis hepatis; (2) BA bacilli can be found both intracellularly and extracellularly; and (3) peliosis is also identified in association with BA in abdominal lymph nodes.