Diagnosis and treatment outcomes for patients with lymphoma of the parotid gland.

OBJECTIVES/HYPOTHESIS Lymphoma of the parotid gland (LPG) is a rare disease. Clinical diagnosis is difficult, due to a lack of specific symptoms and findings. The aim of this study is to evaluate the diagnostic workup based on the analysis of our cases of LPG and to present the stage-dependent treatment outcome. STUDY DESIGN Retrospective case-control study. METHODS From 1992 to 2008, 697 patients at our institution underwent surgery because of a parotid tumor. Among 246 malignancies, an LPG was found histologically in 28 cases (4%). Staging was performed according to the Ann Arbor classification, and treatment was performed by radiotherapy and/or chemo/immunotherapy. The patients were retrospectively analyzed. RESULTS No specific symptoms were found, with the main finding being a unilateral, painless, slowly progressing parotid mass. The sensitivities of imaging and fine-needle aspiration cytology in detecting LPG were 41% and 12%, respectively. Histology was the key to diagnosis, and frozen sections often revealed the diagnosis during surgery, which obviated the need for more extensive surgery in 89% of cases. The 5-year disease-specific survival estimates were 100% and 75% for early tumor stages (I and II) and advanced stages (III and IV), respectively. CONCLUSIONS When the precise nature of a parotid mass remains obscure after fine-needle aspiration cytology and imaging, but LPG is clinically suspected, surgical tissue sampling with frozen sections appears to be a valid option and can prevent the need for more extensive surgery. The treatment outcome for LPG is favorable.