Parotid gland non-Hodgkin lymphoma in primary Sjögren syndrome

The risk of malignant non-Hodgkin lymphoma is increased in primary Sjögren syndrome. In the literature, most studies evaluating this risk were conducted in tertiary reference university hospital. So, selection bias in series exists, in particular selection of the most severe cases in tertiary reference university care centers. Some studies had also a selection bias because patients were hospitalized (data were obtained from hospital discharge registries) and therefore the more severe cases were considered. Between October 1999 and November 2009, 109 adult patients were admitted to our department of internal medicine (non-university hospital, secondary level of the healthcare system, hospitalized patients and outpatient) with diagnosis of primary Sjögren syndrome. Two cases of parotid gland lymphoma occurred during the period of follow-up. No other lymphoma was detected. In this study, clinically identifiable parotid gland non-Hodgkin lymphoma occurs in 1.8% of patients with primary Sjögren syndrome. Because most non-Hodgkin lymphoma initially involves the neck organs, meticulous imaging studies mainly focused on the cervical regions are recommended in the follow-up of patients with primary Sjögren syndrome. Patients whose main complaint is persistent parotid gland swelling may have a parotid biopsy in order to diagnose non-Hodgkin lymphoma.