IgG4-Related Pseudotumor in the Sinonasal Cavity: Presentation of a Case and Literature Review

Immunoglobulin G4-related disease is an increasingly recognized inflammatory condition that was originally associated with autoimmune pancreatitis. Although the involvement of the salivary glands has been reported, the occurrence of immunoglobulin G4-related disease in the sinonasal cavity is uncommon. We present a case of a 42-year-old woman with immunoglobulin G4-related disease involving the sinonasal cavity. The patient presented with a progressive, non-painful lesion on the left nostril and lateral nasal wall that had been present over the course of 7 months. Moreover, there was an enlarged left submandibular gland and cervical lymphadenopathy. Further examination revealed a septal perforation, extensive inflammation of the sinonasal cavity, and a positive Antineutrophil Cytoplasmic Antibodies (c-ANCA) serology. Although the diagnosis of granulomatosis with polyangiitis was initially suspected, histopathology revealed lymphoplasmacytic infiltrations with an increase of immunoglobulin G4-positive plasma cells, confirming the diagnosis of an immunoglobulin G4-related disease. The patient was treated with oral corticosteroids, after which the symptoms improved. Immunoglobulin G4-related disease originating in the sinonasal cavity is uncommon, and presentation as a nasal pseudotumor is considerably rare. Cite this article as: Vercauteren L, Van Haesendonck G, Van Offel S, et al. IGG4-related pseudotumor in the sinonasal cavity: presentation of a case and literature review. B-ENT 2022;18(2):121-127.