IgG4-Related Perineural Disease

Aims . To elucidate characteristics of IgG4-related disease involving the peripheral nervous system. Methods . Retrospective review of 106 patients with IgG4-related disease identified 21 peripheral nerve lesions in 7 patients. Clinicopathological and radiological features were examined. Results . Peripheral nerve lesions were commonly identified in orbital or paravertebral area, involving orbital ( n = 9), optic ( n = 4), spinal ( n = 7), and great auricular nerves ( n = 1). The predominant radiological feature was a distinct perineural soft tissue mass, ranging 8 to 30 mm in diameter. Histologically, the epineurium was preferentially involved by massive lymphoplasmacytic infiltration rich in IgG4 + plasma cells. All lesions were neurologically asymptomatic and steroid-responsive at the first presentation, but one recurrent lesion around the optic nerve caused failing vision. Conclusion . IgG4-related disease of the peripheral nervous system is characterized by orbital or paravertebral localization, perineural mass formation, and rare neurologic symptoms. The term “IgG4-related perineural disease” seems appropriate to describe this entity.