A rare case of human pulmonary dirofilariasis with nodules mimicking malignancy: approach to diagnosis and treatment

Background: Human pulmonary dirofilariasis is a rare zoonosis caused by the dog worm Dirofilaria spp., a parasite transmitted by mosquitos and resulting in peripheral lung nodules. The filarial nematode enters the subcutaneous tissue, travels to the right ventricle and dies causing a small pulmonary infarction that may embolize through the pulmonary vessels and may appear as a solitary nodule. These nodules are usually incidentally identified in asymptomatic patients undergoing chest imaging studies, and are generally interpreted to be malignant. Case presentation: We present the case report of a human dirofilariasis in a patient with multiple pulmonary nodules resected using video-assisted thoracic surgery (VATS). According to our literature review, this is the first case with double synchronous lung nodules reported in Italy. Conclusions: Minimally invasive resection with histologic examination may be the best approach for the diagnosis and treatment of pulmonary dirofilariasis. Polymerase Chain Reaction testing may provide a more accurate etiological diagnosis in case of an inconclusive pathology result.