Systemic-to-pulmonary artery fistula following actinomycosis.

We report a case of pleuropulmonary actinomycosis in a child followed by a most unusual complication: the appearance of a systemic-to-pulmonary artery fistula in the area where the abscess was drained. Fifteen months after successful treatment with penicillin and surgical drainage, a continuous murmur was heard over the scar. Aortic angiography showed multiple connections between the intercostal arteries and the left pulmonary artery through an angiomatous lesion in the left lower lobe. This resulted in a considerable left-to-right shunt. Possible pathogenic mechanisms are discussed.