Disseminated atypical mycobacteriosis in HIV-infected patient with predominant lesion of digestive system (clinical case)

The article is devoted to the description of a rarely diagnosed secondary opportunistic infection in an HIV-infected patient – atypical mycobacteriosis. A feature was the predominant lesion of the digestive system. Clinical, laboratory and instrumental research methods and prognosis are analyzed. The diagnosis was verified only by sectional and histological examinations.

Intrahistiocytic Storage of Clofazimine Crystals in a Cat

A 13-year-old castrated male Maine coon cat with a 5-year history of atypical mycobacteriosis was euthanized and submitted for necropsy. The cat had been kept in clinical remission since diagnosis using a combination of the antimycobacterial drug clofazimine and additional multimodal antimicrobial therapy. Grossly, tissues were diffusely discolored red-brown to yellow. Histologically, the myocardial interstitum was expanded by numerous, often multinucleated cells, which were distended by uniformly shaped acicular cytoplasmic spaces. These cells were immunopositive for CD18 and immunonegative for desmin, suggesting a histiocytic rather than muscular origin. Macrophages in other tissues contained similar acicular spaces. Ultrastructurally, the spaces were surrounded by 2 lipid membranes, resembling an autophagosome. Based on the clinical history and histologic, immunohistochemical, and ultrastructural data, we diagnosed clofazimine crystal storage. To our knowledge, this is the first report of clofazimine storage in a cat or within myocardial interstitial macrophages.