Abstract
Sjögren’s syndrome (SS) is a chronic systemic autoimmune disease primarily affecting the lacrimal and salivary glands. It is broadly classified into primary SS and secondary SS. Primary SS occurs in 50% of cases and affects only the salivary and lacrimal glands leading to dry eyes and dry mouth. Secondary SS is characterized by presence of a secondary autoimmune disease such as rheumatoid arthritis, scleroderma, or lupus along with lacrimal and salivary gland involvement. Approximately 1–2% of US population is diagnosed with SS on an annual basis. Women are primarily affected with the 24:1 female to male ratio, with 52 years as the average age of onset. The parotid gland is most commonly affected and may be enlarged in one-third to one-half of the patients. This enlargement is usually bilateral and asymptomatic. A myriad of other conditions can also produce bilateral or unilateral persistent or recurrent parotid enlargement. This chapter discusses some of the common pathologic entities that may be included in the differential diagnosis of such an enlargement.