IgG4-related sialadenitis: IgG4 is helpful, but biopsies are still crucial

IgG4-related disease is rare, but a frequent differential diagnosis for malignant and for autoimmune diseases. Li and colleagues report the largest cohort of patients with IgG4-related sialadenitis. The observations reveal that the most important diagnostic step is obtaining biopsies. In addition, the IgG4 serum concentration may be a biomarker for the disease progression.