[Three cases of pulmonary dirofilariasis suspected of lung cancer]

We experienced with three patients with pulmonary dirofilariasis found in resected lungs. Two patients showed abnormal shadows on chest roentgenograms without symptoms. Another patients had chest discomfort. All patients underwent diagnostic thoracotomy. Histopathological examination showed necrotic granulomatous lesions surrounded by fibrous tissue and transverse section of Dirofilaria immits was found. It has been an increasing reported disease. It is important to keep in mind the possibility of dirofilariasis.