Massive spontaneous hemothorax as a presenting sign of aneurysmal rupture of the internal thoracic artery. A case report.

Massive spontaneous hemothorax is a very uncommon, life-threatening situation. Acute dissection and ruptured aorta can be one of the differential diagnoses, but usually the clinical feature is completely different, and very few patients have survived this event and received medical attention. Among other causes of spontaneous bleeding, some are extremely rare, demanding precise diagnosis and judicial and immediate intervention. We describe a patient who presented with a massive hemothorax. There was no immediately apparent cause. Emergent angiography revealed active bleeding from an extremely unusual source: aneurysmal dilatation of the internal thoracic artery.