The clinicopathological features of parotid lymphoma.

Lymphoma of the parotid gland is a rare malignant tumor, and cohort studies on the survival rates of affected patients are sparse. This study aimed to retrospectively evaluate the clinicopathological characteristics of patients diagnosed with non-Hodgkin lymphoma of the parotid gland. This study included 31 patients diagnosed with lymphoma of the parotid gland. Data on the pathological subtypes, the WHO classifications of the hematopoietic and lymphoid tissues, and the Ann Arbor staging, treatment modalities, and survival times were collected and analyzed. Among the 31 patients, there were 18 cases of extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT), 7 cases of diffuse large B-cell lymphoma (DLBCL), and 6 cases of follicular lymphoma (FL). The tumors were most-commonly located in the superficial lobe of the parotid gland (28/31), and three cases involved the deep lobe of the parotid gland (3/31). The overall median survival from the diagnosis of lymphoma was estimated to be 62 months, with 3-year and 5-year survival rates of 83.9% and 77.4%, respectively. A univariate analysis demonstrated statistically significant differences in accelerated tumor growth (P<0.001) and the presence of tumor capsules (P<0.001). A multivariate analysis demonstrated statistically significant differences in the accelerated tumor growth (P=0.029). MALT lymphoma was the most common subtype of primary parotid lymphoma. The prognosis is better than it is with other malignant parotid tumors. The presence of accelerated tumor growth was significantly correlated with overall survival time.