Parotid gland lymphoma: prognostic analysis of 2140 patients.

OBJECTIVES/HYPOTHESIS Assess the demographic, clinical, and pathologic features of patients with parotid gland lymphoma and their prognostic importance using US population-based data. STUDY DESIGN Retrospective cohort study. METHODS Patients were selected from the Surveillance, Epidemiology, and End Results program database between the years of 1973 and 2008, and individual characteristics were compared using univariate and multivariate Cox proportional hazards models. Kaplan-Meier survival curves were constructed and log-rank tests were performed. RESULTS We identified 2,140 patients with primary parotid gland lymphoma. Hodgkin lymphoma was found in 3.5% of patients. More common were non-Hodgkin lymphoma subtypes: marginal zone B-cell lymphoma, follicular lymphoma, and diffuse large B cell lymphoma accounted for 27.9%, 25.8%, and 23.7% of cases, respectively. Survival was decreased with patient age over 50 years, increasing stage, male gender, non-Hodgkin histology, and status other than married. Of the patients, 72.0% received some form of surgery, and 136 patients had facial nerve sacrifice during parotidectomy. CONCLUSIONS Non-Hodgkin lymphoma is the predominant type of lymphoma seen in the parotid gland. Patient and histologic features determine survival, and surgery is often performed. Facial nerve sacrifice, which is contraindicated given the systemic nature of lymphoma and the role of chemotherapy and radiation in its treatment, is reported in 6.4% of patients with parotid gland lymphoma. LEVEL OF EVIDENCE 2b.