Systemic fibromuscular dysplasia masquerading as polyarteritis nodosa.

The diagnosis of systemic diseases, such as vasculitis, may be difficult because of an uncharacteristic clinical presentation or the inability to obtain histopathological confirmation. Classification criteria for the systemic vasculitides have been composed as a guide for the diagnostic process. If polyarteritis nodosa (PAN) is strongly suspected histological confirmation is not mandatory for the diagnosis [1]. Characteristic angiographic findings such as visceral microaneurysms provide strong support for the diagnosis of PAN. In the present case the angiographic findings were considered to be typical of PAN but the clinical course and autopsy findings revealed another systemic vasculopathy.