Case presentation

A 40-year-old man presented with numbness of the lower limbs and pain in the lower back for 11 months. Abdominal CT revealed multiple retroperitoneal masses around the left renal hilus and abdominal aorta. Over the subsequent 4 months, the lesions progressed, resulting in hydronephrosis of the left kidney and bone destruction in the L2 vertebral body (figure 1). Three biopsies (two from the L2 vertebral body and one from the retroperitoneal mass) had been previously taken at another hospital. Pathological examination of all three biopsies had resulted in a diagnosis of IgG₄-related disease (IgG₄-RD) (figure 2). He had been taking a moderate dose of methylprednisolone (20 mg/day) for 4 months. Chest CT revealed a nodule in the apical segment of the right lung, 7 months after initial presentation. His symptoms did not improve on treatment with steroids. By 9 months after presentation, the patient had developed paralysis, hypoaesthesia, numbness and pain in both lower limbs. Intravenous methylprednisolone (250 mg/day) …