A patient with acute kidney pain and high blood pressure.

This case presented challenging diagnostic and management issues in a young healthy man who presented with abdominal pain and new-onset hypertension. The differential diagnosis evolved over the course of the clinical presentation. The patient had severe vascular involvement of his renal and basal cerebral arteries that initially was assumed to be due to a vasculitic process or hypercoagulable state. Finally it became apparent that the patient did not have a systemic illness but rather a localized vascular disease most likely due to segmental arterial mediolysis, a rare, under-recognized condition that can potentially be fatal. This condition is often difficult to distinguish from fibromuscular dysplasia. It is important to recognize and correctly diagnose the condition, particularly in the acute phase of the disease, because delay in diagnosis can contribute to morbidity and mortality.