A rare vascular proliferation found as a skin lesion in patients suffering from the acquired immunodeficiency syndrome and sometimes referred to as epithelioid angiomatosis is believed to be a manifestation of infection by the cat scratch bacillus or a related organism. We describe the histological findings from eight lesions seen in two cases. In all cases the diagnosis could be confirmed by demonstration within the lesions of groups of gram-negative rod-shaped organisms staining positively with the Warthin-Starry stain. This condition needs to be distinguished from a variety of reactive and neoplastic vascular proliferations.