Renal botryomycosis.

A case of visceral botryomycosis which arose in the left kidney of a 60-year-old woman is reported. This is the fifth reported case of renal botryomycosis which, in this patient, was mistaken clinically for a renal carcinoma. The lesion was composed of confluent abscesses containing 'sulphur granule-like' lesions in which irregularly lobed aggregates of Gram-negative organisms surrounded by an eosinophilic capsule were noted. Awareness of this unusual lesion is important because of its histopathological similarity to actinomycosis.