First case report of histoplasmosis in a cat in Japan.

Cytological, histopathological and immunohistochemical examinations were carried out on a presumed 10-year-old Japanese cat showing vomiting and emaciation. On cytologic examination of the mass of the upper abdominal cavity, many yeast-like organisms were detected in the macrophages. At necropsy, the upper part of colon was markedly dilated with a thickened wall.