Ultrasonographic features and clinical management of IgG4-related submandibular gland inflammation: a case report.

IgG4-related submandibular gland inflammation (IgG4-RSGI) is an immunologically mediated condition characterized by chronic fibroinflammatory lesions and elevated serum IgG4 levels. It often lacks specific clinical and imaging features, leading to misdiagnosis.We present a case of IgG4-RSGI to enhance clinical recognition and diagnostic accuracy. A patient presented with a four-month history of progressive bilateral submandibular gland enlargement. Ultrasonography revealed bilateral submandibular gland enlargement with heterogeneous internal echoes, a "mesh-like" pattern, and nodular hypoechoic areas. Color Doppler flow imaging (CDFI) showed increased vascularity. Ultrasound-guided biopsy confirmed the diagnosis, establishing ultrasound as a valuable initial diagnostic tool in the clinical assessment of IgG4-RSGI.