Abstract: PO2257
Fibromuscular Dysplasia Masquerading as Polyarteritis Nodosa in a Patient with Raynaud Syndrome
Session Information
- Pathology and Lab Medicine: Clinical
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Report
- 1602 Pathology and Lab Medicine: Clinical
Author
- Alam, Salar, Spectrum Health, Grand Rapids, Michigan, United States
Introduction
Fibromuscular dysplasia (FMD) is a non-inflammatory, non-atherosclerotic vascular disease primarily affecting renal and cerebral arteries. Polyarteritis nodosa (PAN) is a small to medium vessel vasculitis that can be fatal if not promptly diagnosed and treated. Both conditions are commonly diagnosed by angiographic findings which may appear similar.
Case Description
A 49-year-old Caucasian woman with a past history of Raynaud's disease presented to the emergency department with acute onset periumbilical abdominal pain. She was mildly hypertensive on presentation; metabolic panel showed no electrolyte abnormalities; urinalysis showed proteinuria and hematuria; ESR was 7 and CRP 22.7. Notably, she had been on prednisone for a skin rash after poison ivy exposure 5 days prior to presentation. Family history was pertinent for rheumatoid arthritis. CT abdomen and pelvis with contrast revealed multiple right renal infarcts. Subsequently a CT angiogram was obtained. During renal arteriography, the right renal artery developed dissection with minimal catheter manipulation suggestive of significant underlying abnormality. The procedure was aborted given risk for further complications including rupture and hemorrhage. Radiology reported findings consistent with medium vessel vasculitis. Autoimmune workup showed positive ANA, Scl 70 and rheumatoid factor, supporting suspicion for systemic vasculitis such as PAN. However, mesenteric vessels were normal. She was advised to continue on prednisone while additional workup was completed. Carotid dopplers were obtained and demonstrated partial dissection of the mid right internal carotid artery, with subsequent CT angiogram of the head and neck showing findings consistent with FMD throughout vertebral arteries and left internal carotid artery. Initial renal CT angiogram was reevaluated by Radiology, with renal artery beading noted, consistent with a diagnosis of FMD. The patient’s creatinine remained stable throughout her hospital stay, and she was initiated on lisinopril prior to discharge.
Discussion
Fibromuscular dysplasia can be diagnosed by histopathology or angiography. It may manifest as a systemic vascular disease involving multiple vascular beds, mimicking systemic vasculitis. Since treatment of PAN and FMD is vastly different, it is important to consider both differentials and have definitive diagnosis prior to initiation of therapy.