Pathological Study of Adiaspiromycosis in Eurasian Red Squirrel (Sciurus vulgaris orientis) and Brown Rat (Rattus norvegicus) Caught in Tokachi District, Hokkaido

Abstract

　 Multifocal nodular lesions were observed in the lungs of Eurasian red squirrel (Sciurus vulgaris orientis) and brown rat (Rattus norvegicus) caught in Tokachi district, Hokkaido. In histopathological examination, granulomatous inflammation was found in lungs of both squirrel and rat. Spherules from 250 to 350μm in diameter were surrounded by macrophages and multinucleated giant cells. Those spherules lacked obvious internal contents, and clearly indicated trilaminar structure in the cell wall. These results strongly suggest that spherules in the lungs were adiaspores. Pathological diagnosis of both cases was adiaspiromycosis caused by Emmonsia crescens.