Unique case of granulomatous arteritis in a grey mouse lemur (Microcebus murinus) - first case description

Abstract

Overall, diseases of the vascular system are rarely observed entities among nonhuman primates that are commonly associated with systemic infections, septicemia or bacteremia. Rhesus monkeys infected with simian immunodeficiency virus (SIV) may develop a chronic occlusive arteriopathy of unknown etiology in late stages of the disease. This SIV associated arteriopathy is the only well-known specific vascular entity described in nonhuman primates. We herein report a unique case of granulomatous arteritis in a grey mouse lemur affecting multiple organs, which is not comparable to other disease entities formerly described in nonhuman primates. The features of the entity most closely resemble disseminated visceral giant cell arteritis in humans. A concise description of the disease is given, and the differential diagnoses are discussed. An idiopathic pathogenesis is suspected.

Figure 1

Grey mouse lemur (picture by Dr. Manfred Eberle).

Figure 2

Grey mouse lemur, lung. (a) Perivascularly accentuated distribution pattern of the inflammation (arrows) and severe alveolar hemorrhage, scale bar 1 mm. (b) Granulomatous inflammation around a blood vessel, scale bar 100 $\mathrm{\mu }$m. (c) Discreet fibrinoid necrosis of a vessel wall (arrow) accompanied by a severe inflammatory reaction with characteristic giant cells (asterisk), scale bar 40 $\mathrm{\mu }$m. (d) Mixed inflammatory cell infiltrate with eosinophils in the vascular periphery, scale bar 30 $\mathrm{\mu }$m. Hematoxylin and eosin stain.