A survey of thoracic actinomycosis.

We have reviewed the case notes of 19 patients with thoracic actinomycosis. The median age at presentation was 42 (range 9-66) years, 15 were male and 12 were urban residents. Cough, sputum production, chest pain and weight loss were the commonest symptoms. Six patients reported haemoptysis. In contrast with the classical appearances of thoracic actinomycosis, only four patients had cutaneous abnormalities, and only one patient had radiological evidence of bone involvement. The provisional diagnosis was bronchial carcinoma in nine patients, and in seven patients the diagnosis of actinomycosis was only made after resection of the lesion, in two cases by pneumonectomy. The median delay between presentation and diagnosis was 3.5 (range 1-24) weeks. Two patients developed extrathoracic complications, but all patients made a full recovery after receiving antibiotic therapy for a median of 6 (range 1-24) weeks. Thoracic actinomycosis is rare, but should still be considered in the differential diagnosis of a pulmonary lesion thought to be malignant.