[Pulmonary actinomycosis. Fine needle aspiration diagnostic]

We present four cases of pulmonary actinomycosis in patients over 40 years of age, two of them with chronic obstructive pulmonary disease (COPD), showing an increase in productive cough, episodes of dyspnea, hemoptysis and long-term fever. Routine chest radiographs revealed segmental air-space consolidation, suggestive of unresolved pneumonia or neoplasm. Computed tomography (CT) scan showed similar findings to the ones previously described. Sputum cultures for mycobacteriae and Mantoux tests were constantly negative. Due to the poor clinical and radiodological outcome of the patients, a fine needle aspiration (FNA) was made to rule out a neoplasm. Tridimensional filamentous colonies of Actinomyces were observed in cytology. Antibiotic treatment resulted in an improvement of symptoms. The follow-up showed a decrease of the consolidation areas. Pulmonary actinomycosis is rare nowadays and clinical symptoms are unspecific and can be confused with a neoplasm process. Therefore, in patients with risk factors, symptoms of subacute pneumonia and radiologic findings of consolidation, it is advisable to consider pulmonary actinomycosis as a diagnostic possibility. It is a treatable disease and its correct diagnosis by FNA, avoids performing invasive diagnostic tests, delays in the diagnosis and allows for a complete cure by antibiotic therapy.