Objective: Thoracic actinomycosis is a disease that is difficult to diagnose because its appearance varies from similarities with bronchogenic carcinoma to pneumonitis-like tuberculosis infections. Therefore the majority of patients undergo operations for diagnosis. We had seven patients with thoracic actinomycosis which were not diagnosed before operation.
Methods: Between July 1990 and November 1997, seven patients with thoracic actinomycosis were diagnosed after thoracotomy in our centre. They all had non-specific symptoms and radiographic findings, so we failed to diagnose the disease during preoperative examinations. Therefore they all underwent thoracotomy for diagnosis. Four patients were operated because of suspicion of malignancy, two patients were operated because of pulmonary infiltration and abscess formation and one patient because of undiagnosed pulmonary infiltration. Lobectomy was performed in five of them because of destroyed lobes, and wedge resection was performed in two patients. In two patients the disease was diagnosed by fresh smears obtained from specimens in the course of operation and confirmed histopathologically and in the others histopathologically in the postoperative period.
Results: Three major complications, acute renal failure, empyema and persistent air leakage developed in three cases after the operations. Bronchopleural fistula was found in only one of them and the patient died because of uncontrolled infection and sepsis on the 26th postoperative day. All of the other six cases are still alive. We did not observe any other problem in their long-term follow-up. All patients regularly took 20 million units/day of intravenous crystalline penicillin G when they were in the hospital. After that, antibiotic treatment was completed up to 2 months with procaine penicillin.
Conclusions: Sometimes diagnosis of the actinomycosis of the lung is very difficult although it is an infection. In that case thoracotomy is needed for the diagnosis and sometimes for the treatment. In some cases because of the irreversible parenchymal change resective surgery may be needed. Actinomyces israelii infections should be suspected of in chronic infiltrative, nodular, cavitary process and tumour-like mass lesions besides other most probable causes. After diagnosed, it is treated using penicillin chemotherapy at least for 2 months.