Thoracic actinomycosis may occur:
(1) following aspiration
(2) by contiguous spread from head and neck
(3) by contiguous spread from abdomen
(4) as part of disseminated disease
Actinomycosis may involve one or more of the following:
(1) lung
(2) pleura
(3) chest wall
(4) mediastinum
(5) pericardium
(6) heart, including endocardium
(7) esophagus
(8) vertebra
Clinical findings may include:
(1) fever
(2) cough
(3) chest or back pain
(4) weight loss
(5) dyspnea
(6) hemoptysis
(7) chest wall sinus
Imaging studies may show:
(1) pleural effusion, empyema and/or pleural thickening
(2) pericardial effusion
(3) one or more masses or cavitary lesions in the lungs
An ECG may show changes of pericarditis or cardiac arrhythmias.
Drainage or aspirates should be examined for sulfur granules but these may be absent. False negative cultures are fairly common, especially if a specimen is not handled properly or if anaerobic cultures are not performed.
Thoracic actinomycosis may mimic lung carcinoma, so it is important to obtain tissue confirmation of cancer before starting chemotherapy. It may also mimic many other infectious diseases such as tuberculosis or histoplasmosis.
