Most cases of primary salivary mucosa-associated lymphoid tissue lymphoma are associated either with Sjoegren syndrome or hepatitis C virus infection

Salivary gland mucosa-associated lymphoid tissue (MALT) lymphomas (SGML) are rare, as are data concerning their behaviour. We analysed clinical features at presentation, particularly the association with Sjoegren syndrome (SS) and hepatitis C virus (HCV) infection, and outcome in 33 cases of SGML diagnosed between March 1985 and April 2003. There were five males and 28 females, with a median age of 61 years. At presentation, 12/33 (36%) had multiple salivary glands or mucosal involvement and four had bone marrow infiltration. Ann Arbor stage was IE in 15 (46%), IIE in four (12%) and IV in 14 patients (42%). Fifteen patients had a history of SS (46%), two of other autoimmune diseases, seven of HCV infection. No case had both SS and HCV. Of the 29 treated patients, 17 received surgery or local radiotherapy; 69% achieved complete remission. Histological transformation occurred in four (12%). Five patients died (three of lymphoma, two of unrelated causes). The 5 year-overall survival (OS), cause-specific survival and progression-free survival was 85 +/- 8%, 94 +/- 6% and 65 +/- 10% respectively. Overall, the disease course was indolent, despite the advanced stage at diagnosis, and local therapy often appeared to be adequate. The only prognostic factors influencing OS were histological transformation and age. The close association of SGML with either autoimmune diseases or HCV infection in our series (73%) confirms their possible role in the pathogenesis of these lymphomas.