Transplantation of cerebral actinomycosis simulating malignant brain tumor into nude mice. Report of a case.

A case of actinomycotic brain abscess simulating malignant brain tumor is presented. Diagnosis was made by histological examination of the operative specimen and of the organs of xenotransplanted Nude mice. The patient survived 3 months after the operation. None of the characteristic organisms could be detected microscopically at the autopsy in the brain and the lung. Xenotransplantation into Nude mice may be a useful method for the relatively quick identification of the causative agent in cases suspected of actinomycosis.