[Two cases of pulmonary dirofilariasis in Nagasaki Prefecture].

We reported two cases of pulmonary dirofilariasis in Nagasaki Prefecture. Each case was admitted to our hospitals for evaluation of an abnormal shadow on chest X-ray film taken for examination. We strongly suspected lung cancer before operation. It was resected in order to confirm the pathological diagnosis. There was a Dirofilaria immitis in the vessels surrounded by the necrotic tissues. The case of pulmonary dirofilariasis tends to increase in Japan, but the positive rate of dogs with Dirofilaria immitis tends to decrease, because of decreasing breeding places of mosquitoes by the spread of the public sewage system in Nagasaki City.