[Pseudotumor by asymptomatic pulmonary infarction diagnosed by video-assisted thoracic surgery].

Two cases of asymptomatic pulmonary infarction were diagnosed by open lung biopsy with video-assisted thoracic surgery (VATS). Case 1: A pulmonary nodule in right S8b was pointed out in a 62-year-old man undergoing hemodialysis on chest x-ray film and CT. Case 2: A 50-year-old woman had undergone left mastectomy for mammary cancer 3 years previously and total hip replacement 1 year before. Chest X-ray film and CT revealed a pulmonary nodule in the left lower lung field and it was suspected to be metastasis of the mammary cancer. Both cases underwent open lung biopsy by VATS, and asymptomatic pulmonary infarction was revealed. When chest X-ray film shows a nodule in the lower-peripheral lung field in patients with risk factors, pulmonary infarction should be considered.