Ask-Upmark kidney with contralateral renal artery fibromuscular dysplasia

A case of Ask-Upmark kidney with coexistent contralateral renal artery fibromuscular dysplasia is presented with detailed light and electron microscopic findings. Both lesions are known to produce renin-mediated hypertension which was corrected in this patient by nephrectomy and contralateral renal artery bypass. Ask-Upmark kidney is briefly reviewed.