MALT-type lymphoma and Warthin's tumour presenting in the same parotid gland.

Non-disseminated malignant lymphomas of salivary glands occurring in association with Warthin's tumour have rarely been reported. We describe the first case of association of an extranodal mucosa-associated lymphoid tissue (MALT)-type non-Hodgkin's lymphoma with Warthin's tumour of the parotid gland. Total parotidectomy with preservation of the facial nerve was performed. Surgical and pathological evidence confirmed that the parotid MALT lymphoma did not arise in the lymphoid stroma of the Warthin's tumour. Immunostaining of the MALT lymphoma cells proved negative for Epstein-Barr virus and Helicobacter pylori antibodies and polymerase chain reaction assays did not identify human herpesvirus 8. The patient has been followed up for 11 months, without evidence of recurrent disease. It cannot be ruled out that long-term immunological stimulation by the Warthin's tumour may have caused lymphoid accumulation, chronic stimulation of B cells and extranodal parotid MALT lymphomagenesis.