A case of pulmonary acariasis in lung of Japanese macaque

A 20-year-old female Japanese macaque, weighing 8.7 kg, developed severe pulmonary acariasis. Numerous whitish nodules, 2-4 mm, were scattered throughout the lungs. Histologically multifocal granulomatous lesions consisting of a large number of eosinophils, epithelioid cells, foreign body type giant cells, and collagen fibers were aggregated around the mait bodies. Numerous mast cells were also detected in the lesions by toluidine blue staining, and tested positive for tryptase by immunohistochemistry. This may be the first reported case of severe pulmonary acariasis in a Japanese macaque.