Abstract
We aim to present a unique clinical case of 7.10 years old child with nephrotic range proteinuria, hypocomplementemia and fibromuscular dysplasia (FMD) without hypertension or systemic vascular involvement.
Introduction
Fibromuscular dysplasia (FMD) is a non-atherosclerotic disease of the blood vessels characterized by an abnormal growth within the wall of an artery, seen seldom in adults and even less in pediatric population.
Case presentation:
A 7.10 years old boy presented with persistent headache and vomiting, normal b.p (95/51 mmHg) and strong palpable peripheral pulses. Lab showed intact CBC and chemistry and nephrotic range proteinuria (urinalysis with >300 mg/dl protein and 24 hour urine protein collections of 841 to 2390 mg/d). Full serology work up was negative except low C3 79 mg/dl (N 90-180) and intact C4 11.6 mg/dl (N10-40), followed by normal C3 levels. Renal biopsy reveled 6/41 glomeruli with global sclerosis with remainder mild mesangial hypercellularity, tubular atrophy and interstitial fibrosis. Blood vessels showed a markedly thickened wall, extensive medial and segmental intimal fibroplasia embedded with split elastin fibers.
Summary
This clinical presentation of FMD is unique since no hypertension was seen and nephrotic range proteinuria and hypocomplementemia is first to be described in FMD. Pediatric FMD etiology is unknown, but reported cases of genetic AD trait with variable penetrance were described. Low C3 levels suggests an inflammatory component as observed in cholesterol emboli, urticarial vasculitis and one reported case of type I MPGN who developed FMD.
