Beyond the Bone Marrow: Aortic Inflammation in Waldenström’s Macroglobulinemia

Background Peri-aortitis is defined by inflammation of the adventitia layer of the aortic wall that can extend into the connective tissue surrounding the aorta. Primary peri-aortitis refers to IgG4-related or primary inflammatory diseases, whereas secondary causes can be non-inflammatory in nature. The differential diagnosis of peri-aortitis typically includes large vessel vasculitis, small vessel vasculitis, IgG4-RD, systemic connective tissue disease, Erdheim-Chester, infections and malignancy.[1] We present a case of presumed amyloid peri-aortitis secondary to Waldenström’s macroglobulinemia.

Case Report A 79-year-old man with a history of monoclonal gammopathy of undetermined significance (MGUS) underwent CT imaging of the chest, abdomen, and pelvis to evaluate a presentation of weakness, intermittent cognitive changes, facial purpura, elevated inflammatory markers, and an episode of syncope. Imaging revealed circumferential mural thickening of the thoracic and abdominal aorta with perivascular fat stranding, consistent with peri-aortitis. He underwent initial evaluation which revealed leukocytosis, elevated erythrocyte sedimentation rate and elevated kappa:lambda ratio with monoclonal protein spike on serum protein electrophoresis. Otherwise, his lab work was negative for anti-neutrophil cytoplasmic antibodies (ANCA), antinuclear antibodies (ANA), rheumatoid factor, complements, c-reactive protein and infectious work up. He was started on prednisone due to concern for large vessel vasculitis without any change in symptoms. During his evaluation he was also found to have nephrotic-range proteinuria and peripheral edema. A kidney biopsy was consistent with AL amyloidosis. A bone marrow biopsy was consistent with Waldenström’s macroglobulinemia (WM). The vascular findings were reinterpreted as amyloid aortitis secondary to WM. The patient’s corticosteroids were tapered without change in clinical status, and he transitioned to treatment with bendamustine-rituximab chemotherapy with stability of his aorta on repeat imaging.

Conclusion This case demonstrates an unusual cause for periaortitis and demonstrates the need for a comprehensive workup for individuals presenting with this condition including assessment for hematologic malignancies.

References [1.] Marvisi C. La Presse Médicale 2020;49:1-7.