Empyema necessitatis: review of the manifestations of thoracic actinomycosis.

Actinomycosis is a relatively uncommon infectious process involving the chest. A case of thoracic actinomycosis mimicking an inflammatory breast carcinoma in an elderly woman is presented with a review of the literature. The authors suggest that considering this disease in the differential diagnosis of indolent pulmonary parenchymal and pleural lesions is essential if appropriate diagnostic tests are to be obtained and proper therapy initiated, thus avoiding unnecessary invasive procedures.