From Scar to Shunt: Incidental Discovery of Pulmonary Arteriovenous Malformation in a Healthy Adult Trauma Patient.

Pulmonary arteriovenous malformations (PAVMs) are rare vascular anomalies that create right-to-left shunts, predisposing patients to hypoxemia, paradoxical emboli, and cerebral abscess. While often congenital and associated with hereditary hemorrhagic telangiectasia (HHT), they may also be acquired. We describe the case of a 59-year-old Hispanic man who was incidentally found to have a large left lower lobe PAVM with a 1.1 cm feeding artery during evaluation for traumatic injuries. Despite severe hypoxemic respiratory failure, he had no respiratory symptoms or distress. Initial embolization reduced but did not eliminate the shunt, necessitating a second procedure that achieved complete closure. This case reinforces the importance of recognizing that PAVMs can remain clinically silent despite severe physiologic burden and often require staged management when large feeding arteries are involved. Vigilant follow-up and genetic evaluation remain essential to preventing long-term complications.