Immunosialadenitis (Sjögren's syndrome) and lymphoproliferation.

The association of primary salivary gland non-Hodgkin's lymphoma (NHL) and immunosialadenitis (myoepithelial sialadenitis, MESA) is well recognized. Within MESA the whole spectrum of lymphoproliferation starting with a prelymphoma transforming into an early lymphoma and later on into a manifest lymphoma can be observed. These lymphomas represent so-called low grade B-cell lymphomas of mucosa associated lymphoid tissue (MALT), an entity also including lymphoplasmocytoid immunocytoma according to the Kiel classification of NHL. In a few patients a transition into a high grade B-cell lymphoma may occur. The recognition of early stages of lymphomas and their distinction from reactive MESA is only possible by application of immunohistological methods.