Pulmonary actinomycosis complicated by fistula of the chest wall

Actinomycosis is a rare disease caused by Actinomyces spp. The clinical and radiological picture of the disease is uncharacteristic, which delays the diagnosis and can lead to complications. We present a case of pulmonary actinomycosis complicated by a chest wall fistula in a 43-year-old man with advanced tooth decay. The patient was admitted to our Department due to a chest wall fistula with bloody discharge. A few months earlier, he was treated with antibiotics for pneumonia. Since then, weakness, exertional dyspnoea, and weight loss had been observed. On admission, increased inflammatory markers were found in laboratory tests. Chest computed tomography (CT) revealed right-sided encapsulated pleural fluid collection containing gas bubbles, pleural thickening, anterior thoracic wall soft tissues thickening and subcutaneous fat stranding. CT suggested an empyema or a breast either pleural malignancy. The picture suggested a breast or pleural tumour to differentiate with an empyema. Videothoracoscopy was performed, the histological examination of the collected samples revealed granulation tissue and bacterial colony of a morphology corresponding to Actinomyces spp. Pulmonary actinomycosis was diagnosed. Antibiotic therapy according to the guidelines was initiated and dental treatment was recommended. Healing of the fistula and significant regression of lesions in the right lung were achieved. Although it is a rare disease, actinomycosis should be considered in the differential diagnosis of any chronic infiltrative lung lesions.