Background: The incidence rate of idiopathic dilatation of the pulmonary artery (IDPA) has been reported as 0.007%. We performed radical pulmonary resection under 3-port video-assisted thoracic surgery (VATS) in a patient with primary lung cancer and IDPA.

Methods: A 61-year-old man presented with an abnormality identified on chest X-ray during a medical check. Computed tomography revealed a 56-mm pulmonary tumor (diagnosed as squamous cell carcinoma by bronchoscopy) located in S6 of the right lower lobe, with clinical middle and lower interlobular lymph node metastasis on the basis of lymphadenopathy. Moreover, the right and left main pulmonary arteries were dilated, but the common basal artery after branches A4, A5, and A6 was normal. The presence of pulmonary hypertension was ruled out by cardiac catheterization, which revealed a pulmonary artery pressure within the normal range (24/11 mmHg). No infectious disease was present, and the patient did not have any history of chronic inflammatory disease. Therefore, IDPA was diagnosed. Surgery was performed, and the intraoperative findings were consistent with those of preoperative CT. Although there were concerns that the pulmonary artery wall might have been weakened due to IDPA, all pulmonary arteries, including the dilated right intermediate trunk, were cut safely with a stapler in this case.

Conclusions: In this case, the intraoperative and histopathological findings demonstrated no fragility of the pulmonary arteries, and the pulmonary artery was safely dissected using a stapler in 3-port VATS. However, radical surgery for lung cancer with IDPA is rare, and the safety needs to be verified by accumulating of further cases in the future.