[A case of pulmonary dirofilariasis with a single nodule on an apical lesion of the right upper lobe].

A 75-year-old man with chronic gastritis and gastro-esophageal regurgitation syndrome was admitted to our hospital complaining of continuous productive cough, and an abnormal shadow was noted on a chest X-ray film. Chest computed tomography revealed a nodule 2.8 cm in diameter with a regular margin on the right apex. Fiberoptic bronchoscopy was performed, but did not yield a definitive diagnosis. We suspected primary lung cancer, and therefore, lung partial resection was performed under thoracoscopic surgery. The intraoperative pathological findings revealed inflammatory granuloma with necrosis, and pulmonary dirofilariasis was finally diagnosed. Pulmonary dirofilariasis is an important differential diagnosis in elderly patients with a chest abnormal nodular shadow. Lesions have been reportedly observed in the peripheral portion of the right lower lobe in many previous reports. However, in this case, a nodular lesion was noted in the right apex.