IgG4 Related Disease of The Larynx Mimicking Malignancy: A Case Report and Review of the Literature

Abstract Objectives: Immunoglobulin G4–related disease is characterized by increased serum IgG4 level, enlargement in the relevant organs and histopathologically intense storiform fibrosis, lymphoplasmacytic infiltration rich in IgG4 positive plasma cells, and obliterative phlebitis. Methods and Results: In this report, a patient who underwent a laryngeal biopsy with a pre-diagnosis of malignancy, but had findings consistent with immunoglobulin G4–related disease in the biopsy sample, is described. Conclusion: Immunoglobulin G4–related disease can be seen in very rare localizations. It should be kept in mind in differential diagnosis when tissues especially containing inflammation rich in plasma cells are encountered. Clinical, laboratory and pathological correlation is extremely important in the diagnosis of an IgG4-related disease.