Undiagnosed Marfan's Syndrome Presenting with Primary Spontaneous Pneumothorax in a Young, Short, Nonsmoker Adult at Emergency.

Marfan's syndrome is an autosomal dominant multisystem connective tissue disorder. It commonly presents with complications of aortic dissection, aortic root dilation, or mitral valve prolapse, or less likely with primary spontaneous pneumothorax (PSP) in the emergency department (ED). A 22-year-old male patient presented with undifferentiated chest pain to our ED. The patient was diagnosed with spontaneous pneumothorax, and further examination was suggestive of Marfan's syndrome. The patient was treated with intercostal tube placement and was advised to follow-up at a higher center for genetic testing. It would be prudent for ED physicians treating spontaneous pneumothorax to suspect, examine, and educate patients, guiding them to a confirmatory diagnosis.