IgG4-related disease with atypical laryngeal presentation and Behçet/granulomatous polyangiitis mimicking features.

The following report describes two male patients with an ongoing medical history with a predominant laryngeal focus, who were finally diagnosed with IgG4-related disease (IgG4-RD). Their primary symptoms included hoarseness and pain of the throat, and they had undergone multiple laryngeal surgeries and laser treatments due to tumorous growth with limited success. Due to the onset of additional symptoms, they initially received the diagnoses granulomatous polyangiitis (GPA) and Behçet's disease. However, further analysis showed elevated IgG4 levels in serum and infiltration of IgG4-positive plasma cells upon biopsy of laryngeal and pulmonary tissue. Treatment was started with moderate doses of prednisone, leading to a rapid resolution of symptoms.