Pulmonary Actinomycosis Masquerading as Malignancy.

An 81-year-old ex-smoker with chronic cough and weight loss had imaging showing right upper-lobe nodules, tree-in-bud changes and bronchial obstruction. Bronchoscopy revealed a right upper lobe bronchus polypoidal mass with histological evidence of actinomycosis. This case highlights actinomycosis mimicking malignancy and the need to exclude wider differentials and cancer mimics.