Neurofibromatosis and arterial aneurysms.

Neurofibromatosis (NF) is a common autosomal dominant disease characterized by the development of hamartomatous or neoplastic lesions due to the proliferation of neural crest cells. An association of aneurysmal arterial lesions with NF, which may have catastrophic complications, has been rarely reported. Our recent experiences with the diagnosis and management of three male NF patients with aneurysms is described. A 19-year-old-man with refractory hypertension due to unilateral, complex, unreconstructable renal artery aneurysms was successfully treated by nephrectomy. Histopathology demonstrated intramural renal artery Schwann cell proliferation. A 44-year-old patient underwent ligation of a ruptured superior mesenteric artery aneurysm. Finally, a femoral-popliteal artery saphenous vein bypass graft with aneurysm exclusion was performed in a 58-year-old-man with a 3.5 cm symptomatic popliteal artery aneurysm. In NF, the underlying pathology in large arteries is intramuscular Schwann cell proliferation with secondary fibrosis. Mesodermal dysplasia may affect small arteries resulting in stenosis, post-stenotic dilatation, or aneurysmal degeneration. Clinicians should be aware of the unusual association of NF with aneurysms, particularly the occult development of visceral and renal artery aneurysms. These lesions are subject to sudden rupture with potentially devastating consequences, and they mandate a high index of suspicion in NF patients.