Salivary gland MALT lymphoma associated with Helicobacter pylori infection in a patient with Sjögren's Syndrome.

We report a case of salivary gland MALT lymphoma in Sjögren's syndrome associated with localized H. pylori infection. A 76-year-old woman had a history of bilateral cheek masses for two years. Histologically, the parotid glands were invaded by numerous centrocyte-like cells to form lymphoepithelial lesions. The tumor cells showed immunohistological differentiation into B cells. Southern blotting demonstrated immunoglobulin gene rearrangement. These results indicated that the tumors were MALT lymphoma. H. pylori, as assessed by the urease test (CLO test; BML Ltd., Tokyo, Japan), was positive in the tumor specimen. After wide local excision of the tumors followed by radio therapy and oral administration of antibiotics and proton pump inhibitor, no evidence of recurrence was found during the 24-months of follow up. H. pylori infection in the salivary gland is rare, although the source of infection and transmission of H. pylori organisms has been thought to be the oral cavity. We discussed the association between H. pylori infection and salivary gland MALT lymphoma. The microorganism may play a role as an additional antigenic stimulus for the development of salivary gland MALT lymphoma as well as for the development of gastric MALT lymphoma. This means that H. pylori can play a role in lymphoma progression as booster of B cell lymphoproliferation.