A 4-year-old boy with neurofibromatosis and severe renovascular hypertension due to renal arterial dysplasia.

A 4-year-old boy had severe hypertension, cardiac failure, and signs of neurofibromatosis. Arteriography disclosed renal artery stenosis in both kidneys with signs of ischemia, particularly in the right kidney. Because of insufficient response to antihypertensive therapy, a right-sided nephrectomy was performed. Histological examination of this kidney showed segmental stenosis in all branches of the renal artery. The vascular lesions were characterized by an intimal proliferation of spindle cells in a mucoid matrix with destruction of the internal elastic membrane frequently accompanied by loss or attenuation of the media and fibrosis of the adventitia. Occasionally, a nodular arrangement of the spindle cells at the interface between intima and media was observed. Immunohistochemical studies demonstrate a smooth-muscle cell origin for these cells.