Epidural inflammatory pseudotumor in the thoracic spine in a patient with polymyalgia rheumatica

Background context: Only six previous cases of epidural inflammatory psedotumor in the spine have been reported. None of them were seen in the course of polymyalgia rheumatica (PMR).

Purpose: To describe a rare case of epidural inflammatory pseudotumor in the thoracic spine in a patient with PMR.

Study design: Case report.

Methods: A 63-year-old man had a 6-year history of PMR treated with prednisone and cyclosporine. He presented with gait disturbance. Magnetic resonance imaging on the 12th day after the onset of the symptoms showed spinal cord compression caused by a posterior epidural mass at the T5-T6 level.

Results: The patient underwent a T5-T6 laminectomy and a total excision of the mass, which involved the ligament flavum and epidural adipose tissue and firmly attached to the dura mater. Histopathologic examination revealed severe lymphoplasmacytic infiltration with fibrosis in the entire specimen and no evidence of hematomas or tumorous lesions. After surgery, the patient's neurologic symptoms disappeared immediately. Two years after surgery, the patient is neurologically normal and has not had a recurrence.

Conclusions: This report identifies a rare case of epidural inflammatory pseudotumor in the thoracic spine in a patient with PMR.