Pulmonary artery hypoplasia associated with posterior mediastinal hematoma accompanied by a ruptured pseudoaneurysm of the esophageal branch of the left gastric artery

A 65-year-old woman with no significant medical history visited the emergency department complaining of epigastric discomfort. A computed tomography of the thorax and abdomen showed the attenuation of the pulmonary artery and a posterior mediastinal hematoma. Angiography showed a tortuous esophageal branch of the left gastric artery and a pseudoaneurysm, and during the later phase, the left lower lobe of the lung was enhanced, and finally, the left pulmonary vein was enhanced. We considered that the patient was exhibiting hypoperfusion of the left pulmonary artery arising from left pulmonary artery hypoplasia, since the left lung was supplying the systemic circulation. Transcatheter arterial embolization was performed. The patient has not experienced any recurrence of a ruptured pseudoaneurysm or epigastric discomfort. Here, we report the first documented case of pulmonary artery hypoplasia associated with posterior mediastinal hematoma accompanied by a ruptured aneurysm of the left gastric artery.