IgG4-related Paravertebral Mass and Peri-aortitis.

A 57-year-old man presented at our clinic with a 1-year history of back pain. Blood tests showed high levels of IgG4 (209 mg/dL), C-reactive protein (5.1 mg/dL) and myeloperoxidase-antineutrophil cytoplasmic antibody (ANCA) (27.4 U/mL), whereas the proteinase 3-ANCA level was normal (<1.0 U/mL). Computed tomography revealed paravertebral and abdominal periaortic lesions (Picture 1) that showed a fluorodeoxyglucose (FDG) uptake on FDG positron emission tomography (Picture 2, 3). Because some patients demonstrating granulomatosis with polyangiitis (GPA) have prevertebral lesions simulating IgG4-related disease (IgG4-RD) (1), we performed an open surgical biopsy to obtain an accurate diagnosis. A specimen from the abdominal periaortic lesion, in which the FDG uptake was strong, showed IgG4-positive plasma cells (IgG4/IgG-positive cells >40%). Although both neutrophil infiltration and tiny granulomas were also observed, there was no evidence of head, neck, lung, or kidney disease, which are typically associated with GPA. We therefore diagnosed the patient to have IgG4-RD (2). Corticosteroid treatment resulted in a resolution of the physical and imaging abnormalities.

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The authors state that they have no Conflict of Interest (COI).