[Bacillary angiomatosis related to Rochalimaea quintana. Anatomoclinical and ultrastructural study of cutaneous localizations in AIDS].

We report a case of bacillary angiomatosis in a 53-year-old homosexual man with acquired immunodeficiency syndrome (AIDS). Pathological and bacteriological studies of cutaneous nodules led to the identification of a rickettsia: Rochalimaea quintana. This observation prompted us to relate the clinical presentation of cutaneous and visceral forms of this disease. Histopathological patterns are also considered. They usually consist in a lobular proliferation of capillaries with plump and sometimes epithelioid endothelial cells. Polymorphonuclear cells, histiocytes and necrotic areas may be present. The most characteristic feature is the presence of interstitial, granular and amorphous clusters of bacteria. Diagnostic problems can be raised with Kaposi's angiosarcoma which can be associated with bacillary angiomatosis. Two types of Rochalimaea have so far been isolated in this disease i.e., R. henselae which is the most frequently involved, and R. quintana. The usefulness of making such a diagnosis resides in the sensitivity of bacillary angiomatosis to antibiotics, emphasing the need to carefully look for the presence of bacterial clusters when atypical angioproliferative lesion appears in patients with AIDS.