Clinicopathological aspects of mucosa-associated lymphoid tissue (MALT) lymphoma of the parotid gland: a retrospective single-center analysis of 28 cases.

BACKGROUND

In contrast to its gastric counterpart, mucosa-associated lymphoid tissue (MALT) lymphoma of the parotid gland has not been studied extensively. We analyzed the clinicopathological features and the clinical course of all patients with parotid gland MALT lymphoma diagnosed and treated at our institution.

METHODS

Patient characteristics including an underlying autoimmune disease, disease stage, genetic aberrations, treatment, and clinical course were assessed and evaluated. Twenty-eight patients (19 women, 9 men) were identified; median age at diagnosis was 49 years (interquartile range [IQR], 40-56), and 18 patients (64%) had an underlying autoimmune disease. Eleven had stage IE, 7 patients had stage IIE, and 10 had advanced disease (stage IV).

RESULTS

Genetic aberrations were detected in 9 of 20 patients; 5 patients had trisomy 3, 2 patients had a t(11;18)(q21;21) translocation, 1 had trisomy 3 and 18, and 1 patient had a t(14;18)(q32;q21) translocation plus trisomy 18. After a median follow-up time of 62 months (IQR, 32-98 months), 24 patients (86%) are alive. Fifteen patients are free from lymphoma, whereas 13 patients (46%) have had a relapse.

CONCLUSION

Our data suggest that MALT lymphoma of the parotid gland is often associated with autoimmune diseases and that trisomy 3 is the most common genetic feature of this disease. The high rate of relapse warrants further study on optimal therapy of such patients.