Primary non-Hodgkin lymphoma of the parotid gland: a case report.

Most malignant lymphomas of the head and neck region are non-Hodgkin lymphomas (NHL), and diffuse large B-cell lymphoma is the most common subtype. The prevalence of malignant lymphoma among parotid tumors is low, approximately 1% to 4%. The most common symptom of parotid lymphoma is a unilateral, non-tender, firm mass that slowly grows in size over time. As its clinical manifestations are non-specific, a comprehensive assessment is required for an accurate diagnosis. The initial work-up includes imaging tools, such as computed tomography and magnetic resonance imaging. However, NHL of the parotid gland is difficult to distinguish from other types of benign tumors prior to biopsy; histopathological evaluation and subsequent immunohistochemical staining are needed for the final diagnosis. Once a definitive diagnosis is established, patients should be referred to an oncologist for staging. Treatment is mainly based on systemic chemotherapy, whereas radiotherapy is indicated for certain cases. Here, we report the case of a 53-year-old man who presented with a progressively enlarging mass in the right parotid area, which was later diagnosed as malignant lymphoma of the parotid gland after superficial parotidectomy.