When Arteries Twist and Kidneys Shrink: A Case of Fibromuscular Dysplasia with Right Upper-Quadrant Abdominal Pain

Introduction: Fibromuscular Dysplasia (FMD) is frequently underrecognized because of its non-specific symptoms and often attributed to more common conditions leading to delay in diagnosis. In this case report, we present a patient managed for Hypertension (HTN) for decades who was found to have FMD after a hospitalization for right upper quadrant (RUQ) abdominal pain. We discuss importance of early recognition and diagnosis. Case Description: A 49-year-old female with a history of HTN diagnosed since age 18, nearly thirty years later, hospitalized for acute RUQ pain radiating to flank. A renal angiogram identified 2 right renal artery aneurysms requiring endovascular coil embolization. CT abdomen revealed atrophy of the right kidney and she was referred to Nephrology. Review of symptoms include tension-like headaches. She is a former smoker and social drinker. Family history non contributary. Medications: Amlodipine 5 mg, Lisinopril-HCTZ 20-25 mg, and aspirin 81 mg daily. Physical exam no bruits. Urinalysis 2+ blood. Her GFR was 55 ml/min, negative ANCA antibodies, non-reactive RPR, low plasma aldosterone/renin ratio of 0.2 and renin level of 54 ng/L. Normal cystoscopy within the past year. Carotid ultrasound found 50-60% stenosis of left internal carotid artery. CTA of the neck was unremarkable. Discussion: FMD is a non-inflammatory, non-atherogenic arteriopathy affecting small and medium-sized arteries with diverse non-specific clinical manifestation like HTN (65%) and tinnitus (27.5%). It predominately affects middle age women (91%). The renal and extracranial carotid and vertebral arteries are most commonly involved(1,2). Diagnostic delays result in poorly controlled HTN, increased risk of TIA, stroke, arterial dissection, or aneurysm rupture. Contributing factors include perceptions of FMD as a rare disease, limited awareness among healthcare providers, and the non-specific nature of its presenting symptoms(1). Diagnosis can be made by the pathognomonic “string of beads" sign on CT Angiography of the renal arteries stenosis(2). We believe our patient had long-standing renal artery stenosis, but late diagnosis resulted in symptomatic renal artery aneurysms that required urgent coil embolization. Optimal treatment may involve a multidisciplinary team approach to achieve the best patient outcome(3).