摘要Pulmonary actinomycosis is difficult to diagnose,and many clinicians lack an understanding of the disease.Delayed diagnosis and misdiagnosis are common.Diffuse panbronchiolitis(DPB)is a rare clinical and pathologic syndrome that involves pulmonary bronchiolitis and chronic sinusitis.This report describes a case of DPB complicated with pulmonary actinomycosis.A 77-year-old Chinese male was admitted with complaints of chronic cough,expectoration,shortness of breath,and fever.He had a history of smoking,drinking,and dental caries.Chest examination revealed coarse crackles.Pulmonary function tests showed an obstructive defect.Computed tomography of the chest showed consolidation shadows,thickening and dilatation of bronchiolar walls,and diffuse central lobular nodules in both lungs.Histopathological examination of a surgical lung biopsy specimen confirmed DPB combined with actinomycosis.The patient's symptoms and radiological findings were significantly improved after penicillin combined with azithromycin therapy.Actinomycosis should be considered in older men who have structural lung diseases with recurrent lung infections.Early histological diagnosis and combination antibiotic therapy are very important in such patients.