Benign salivary gland hypertrophy, also known as sialadenosis or degenerative salivary gland enlargement, is a non-neoplastic, non-inflammatory, chronic, recurrent, painless enlargement of the salivary gland. The exact etiology of benign salivary gland hypertrophy is unknown, but the possible causes are (Table 9-2): ① endocrine disorder: most often seen in diabetes metllitus, obesity, etc.; also seen in thyroid disease, gonadal dysfunction, hormonal changes such as puberty and menstruation. ② malnutrition: vitamin and protein deficiency, alcoholism or cirrhosis, etc.; ③ dysfunction of autonomic nervous system: is a more common cause, part of which is central sexual dysfunction, such as psychological factors and certain psychotropic drugs caused by the other part of the system Peripheral dysfunction, such as some anti-hypertensive drugs can destroy the peripheral sympathetic nerve fibers, affecting the protein synthesis and secretion of the glandular cells. Histopathological manifestations include enlarged alveoli, two to three times the diameter of normal alveoli, nuclei pushed to the basal side of the cells, significant swelling of the cells, and PAS-positive secretory granule in the cytoplasm. Clinical manifestations The vast majority of parotid glands and a few submandibular glands are affected. Most of them are bilaterally swelling, occasionally unilaterally. It is usually seen in middle-aged and elderly people. The enlargement of the parotid gland is gradual and can last for years, with a history of recurrent painless swelling, sometimes large and sometimes small, but does not completely resolve. The gland is diffusely enlarged (diffuse swelling) and is soft and uniform to palpation. In older cases, the gland is slightly hard and tough, but there is no mass, no pressure pain, no redness or swelling at the mouth of the duct, and there is still clear fluid secretion when the affected gland is squeezed. Sometimes the secretion is reduced, but the patient has no obvious dry mouth (xerostomia). Diagnosis and differential diagnosis Salivary gland imaging shows mostly normal morphology, but with a marked increase in volume and slightly delayed emptying function. Benign salivary gland hypertrophy is sometimes differentiated from salivary gland tumors and Schegren’s syndrome. In cases of unilateral salivary gland hypertrophy, the clinical palpation is sometimes inaccurate and the posterior maxillary area is felt to be full. Ultrasound examination is preferred in such patients and can confirm the diagnosis if it shows an enlarged gland with homogeneous echogenicity and no occupying lesions. Salivary gland enlargement can also be present in Schegren’s syndrome, but on salivary gland imaging, the dilated terminal ducts and delayed emptying function are much more pronounced than in benign salivary gland hypertrophy, and immunological tests are mostly abnormal. Treatment There is no specific treatment available. In patients with systemic diseases, the gland may return to normal in some patients after systematic treatment. However, in some patients with diabetes mellitus, the enlarged salivary glands do not change significantly despite ideal control of diabetes. Most of the swollen salivary glands caused by anti-hypertensive drugs can subside after stopping the drugs. For those with symptoms of swelling, patients can be asked to massage the gland themselves to encourage the gland to empty the saliva. Chewing sugar-free gum, or using salivary stimulants such as pilocarpine to stimulate saliva production.