IgG4-related disease presenting with an epidural inflammatory pseudotumor: a case report.

BACKGROUND Inflammatory pseudotumor is a rare clinical condition that can be related to immunoglobulin G4 disease. Only a few cases of spinal inflammatory pseudotumors have been reported in the literature and an association with immunoglobulin G4 disease was not conclusive in any of them. We describe what we believe to be the first biopsy-proven case of an epidural inflammatory pseudotumor related to immunoglobulin G4 disease. CASE PRESENTATION A 57-year-old Caucasian woman presented to our hospital with severe paraparesis, gait disturbance, and sensory loss secondary to a relapsing epidural mass. Examination of a biopsy specimen revealed a lymphoplasmacytic infiltration with fibrosis and an immunoglobulin G4-positive plasma cell ratio of over 50 %, which are compatible with a diagnosis of immunoglobulin G4-related inflammatory pseudotumor. Our patient was successfully treated with systemic and epidural administration of glucocorticoids. CONCLUSION Immunoglobulin G4-related disease is an emerging clinical condition in which central nervous system involvement is still uncommon. We describe the case of a patient with an epidural mass with medullar compression, which was proved to be an immunoglobulin G4-related epidural inflammatory pseudotumor. Our findings suggest a new manifestation of immunoglobulin G4-related disease. This disorder should be considered in the differential diagnosis of spinal tumors as a potentially treatable condition with glucocorticoids.