[Thoracic actinomycosis. Report of 8 cases]

We report 8 cases of thoracic actinomycosis, a disease which is now uncommon owing to the widespread use of antibiotics and which is caused by anaerobic filamentous bacteria living as saprophytes in natural cavities. Recent pathogenetic data, such as propagation by continuity or blood stream, as well as bacteriological and clinical data (mediastino-pulmonary, pleural, parietal, cardiac and disseminated lesions) are reviewed. Diagnostic problems are due to the difficulties encountered in trying to isolate the saprophytic organism, and pathological examination is often required for the diagnosis. Treatment is basically medical and consists of penicillin G or A administered for prolonged periods. Nitroimidazoles are ineffective against these anaerobic bacteria.