Wegener granulomatosis with back pain, periaortitis, and dural inflammation developing while receiving monthly cyclophosphamide.

A 61-year-old white man was admitted to our department because of severe back and upper abdominal pain of 1 month's duration. The patient was diagnosed with Wegener granulomatosis 10 months before the presentation based on chronic otitis media, hoarseness, and hemoptysis; positive c-ANCA; and laryngeal and lung biopsies showing multinucleated giant cells. The patient was treated with monthly injections of cyclophosphamide (1-1.5 g per month) and 80 mg prednisone daily with rapid improvement. Prednisone dose was tapered off and 1 month before the present admission, the patient developed severe low back pain. Extensive workup, including abdominal computed axial tomography scan, computed tomography angiography, magnetic resonance image of the spinal cord, and fluorodeoxyglucose-positron emission tomography (FDG-PET) scan, revealed 2 periaortic soft tissue structures seen at the level of L3 and at the level of the celiac trunk and linear meningeal thickening of the spinal cord at the level of D4-8. All these structures showed strong signal on FDG-PET scan. Treatment with methylprednisolone (1000 mg/d) for 3 consecutive days followed by 80 mg prednisone per day and 100 mg cyclophosphamide per day was started with rapid attenuation of the patient's symptoms. This case describes the clinical course of the rare complication of Wegener granulomatosis, periaortitis, and dural inflammation despite monthly cyclophosphamide and demonstrates the role of magnetic resonance imaging and FDG-PET in their diagnosis.