Immunoglobulin G4-related Disease with Solitary Nasopharynx Involvement Mimicking Nasopharyngeal Tumor: A Case Report

Abstract

Immunoglobulin G4-related disease (IgG4-RD) presenting with isolated nasopharyngeal involvement is rare. A 51-year-old man presented with left-sided otalgia and temporal tingling. Magnetic resonance imaging showed a 2.5-cm infiltrative soft tissue lesion in the left nasopharynx, initially suspected of being nasopharyngeal carcinoma. Serum IgG4 levels were normal. The first biopsy was inconclusive; however, a second, deeper biopsy confirmed IgG4-RD based on storiform fibrosis, dense lymphoplasmacytic infiltration, and increased IgG4-positive plasma cells. The patient responded well to moderate-dose glucocorticoids and azathioprine. IgG4-RD should be considered in the differential diagnosis of mass-forming lesions in the nasal cavity, even in the absence of elevated serum IgG4 levels.