Immunoglobulin G4 Related Disease in the Paranasal Sinus: A Rare and Emerging Entity.

Immunoglobulin G4 related disease (IgG4-RD) is a rare immune mediated condition characterized by extensive tissue fibrosis and infiltration by immunoglobulin G4 positive plasma cells in a single or multiple organs. Earlier known to be a rare occurrence, it is becoming increasingly documented worldwide. Organs predominantly involved in this condition are pancreas, salivary glands and biliary tract while in the head and neck region, the salivary, lacrimal and pituitary glands are commonly affected structures. There are limited documented cases reporting IgG4-RD affecting the nasal cavity and paranasal sinuses to the best of our knowledge. Here in we report a case of a young female with complains of chronic rhinosinusitis, previously misdiagnosed on multiple occasions, later diagnosed with IgG4-RD on the basis of histopathology. Even though the prognosis is favorable, but delay in diagnosis and therapy can lead to multi organ failure and premature death hence warranting the need for discussion.