A rare case of human pulmonary dirofilariasis with a growing pulmonary nodule after migrating infiltration shadows, mimicking primary lung carcinoma

•Lung dirofilariasis was seen as a growing coin lesion and a migrating infiltration shadow.•The differential diagnosis of lung dirofilariasis should include primary lung carcinoma or metastatic lung tumor.•Wedge resection under video-associated thoracic surgery is useful for the diagnosis.

IntroductionPulmonary dirofilariasis is a rare pulmonary parasitic infection by the nematode Dirofilaria immitis. It is characterized by an asymptomatic pulmonary nodule usually seen on chest X-ray. The differential diagnosis of pulmonary dirofilariasis includes other pulmonary diseases, primary lung carcinoma and metastatic lung tumor.Case presentationPulmonary dirofilariasis was diagnosed in a woman who presented with interstitial pneumonia. Growth of the pulmonary nodule was detected subsequent to hemoptysis. The histological diagnosis was made based on a wedge resection performed under video-associated thoracic surgery (VATS).ConclusionPulmonary dirofilariasis often varies in its clinical course. The diagnosis is best made using wedge resection under VATS.