A 76-year-old man was seen in the clinic for a painless mass in his left upper neck. Physical examination and computed tomography showed an enlargement of the left submandibular gland. Sonography revealed multiple lobulated hypoechoic lesions within the enlarged left submandibular gland. Excision of the left submandibular gland was performed smoothly. The specimen showed interlobular fibrosis and atrophic acini. There was lymphoplasmacytic infiltration, which had increased immunoglobulin G4 (IgG4) positive plasma cell populations in the gland. The patient’s serum IgG4 was 189 mg/dL, far beyond the reference level of 8-140 mg/dL. These findings were all consistent with IgG4-associated sialadenitis. The man did not receive systemic steroid therapy after the surgery. No disease recurrence was observed in the following year after excision. Though IgG4-associated sialadenitis is usually highly sensitive to steroids, the diagnosis is often made after surgical resection, which is usually also curative. Systemic corticosteroid therapy could be reserved for use in cases of refractory or recurrent diseases. (J Taiwan Otolaryngol Head Neck Surg 2022; 57:155-160)
