Exertional hypoxia in a healthy adult: a pulmonary arteriovenous malformation.

Pulmonary arteriovenous malformations (PAVMs) are a rare cause of pulmonary symptoms, including dyspnoea on exertion, hypoxemia and haemoptysis. PAVMs are an aetiology that is often overlooked by physicians when developing a differential diagnosis for pulmonary symptoms and unidentified lung masses. However, it is an important differential diagnosis to have as PAVMs can have serious sequelae including strokes, brain abscess and life-threatening bleeding. We present a case of an impressive PAVM presenting with chest pain, chronic cough, feelings of anxiety, mild resting hypoxemia and exertional hypoxemia. Of note, on previous chest X-ray, 8 years prior to presentation, an incidental mass was found during a shoulder repair presurgical workup but not further evaluated.