Pulmonary artery pseudoaneurysm showing rapid growth in a patient with lung cancer

Pulmonary artery pseudoaneurysm is rare and is usually associated with infection. In this report, we describe the case of a patient with pulmonary artery pseudoaneurysm in association with pulmonary squamous cell carcinoma. A 64-year-old man with a previous history of lung cancer showed massive hemoptysis and large consolidation in the right lower lung. Emergency radiologist interpreted this lesion as cancer progression or hematoma. Thus, emergency bronchial and intercostal angiography were performed. However, during admission, the patient presented with another episode of massive hemoptysis. A thoracic radiologist reviewed the previous computed tomography scans and noted the presence of a large hematoma in the right lower lobe of the lung; a pseudoaneurysm was seen within the hematoma arising from the pulmonary artery. On follow up computed tomography, the pseudoaneurysm showed rapid growth. Thus, the patient underwent embolization for the branch of the right lower lobar pulmonary artery using coil and histoacryl. Misdiagnosis of pulmonary artery pseudoaneurysm could be fatal; hence, radiologists should be familiar with the features of pulmonary artery pseudoaneurysm.