A Tumefactive Fibroinflammatory Lesion of the Head and Neck Mimicking Immunoglobulin G4-related Disease.

A 67-year-old woman with a 5-year history of recurrent swollen eyelids and epistaxis, diagnosed as immunoglobulin G4-related diseases (IgG4-RD) based on hyper-IgG4-emia and IgG4-positive cell infiltration to the lesion, was referred to our department due to recurrent symptoms despite corticosteroid therapies. Computed tomography revealed an osteoclastic sinus mass with prominent neutrophil infiltration and necrosis that was incompatible with IgG4-RD histopathologically. Finally, she was diagnosed with a tumefactive fibroinflammatory lesion (TFIL) of the head and neck and treated with high-dose corticosteroids. Physicians should remember that TFIL can mimic IgG4-RD in the head and neck region with prominent neutrophil infiltration and necrosis.