Ultrasonographic Features of Immunoglobulin G4-Related Sialadenitis

The aim of this study was to determine the role of ultrasonography in the diagnosis and follow-up evaluation of immunoglobulin G4-related sialadenitis. In this study, 42 patients with immunoglobulin G4-related sialadenitis underwent ultrasonography of the parotid and submandibular glands, and the sonographic appearance was compared with the pathologic findings. Post-treatment ultrasonographic appearance was compared with the pre-treatment findings in 30 patients who received immunomodulatory therapy. The ultrasonographic appearance of the affected glands was divided into five patterns: superficial hypo-echoic, multiple hypo-echoic foci, whole-gland heterogeneity, space occupying and normal echo. Histopathologic examination revealed marked lymphoplasmacytic inflammation and inter-lobular fibrosis, which were more severe in the superficial than deep portion of the affected glands. After treatment, the volume of the affected gland decreased significantly, the internal echo became more homogeneous and the superficial hypo-echoic area disappeared or was reduced. In conclusion, ultrasonography may play an important role in the diagnosis and follow-up evaluation of immunoglobulin G4-related sialadenitis.