Primary actinomycosis of the breast: a clinical review and a case report.

An uncommon situation of primary actinomycosis of the breast is reported in a 40-year-old woman who presented with a lump, clinically simulating malignancy, in the right breast. Diagnosis of actinomycosis was established by incision biopsy. Resolution of infection, while conserving the breast, was achieved by timely diagnosis, limited surgery, and effective antibiotic therapy. Diagnostic failures leading to avoidable mastectomies have not been uncommon in cases previously reported in the literature. It is, therefore, imperative that this condition be considered in the differential diagnosis of intractable breast abscess and malignancy.