Objective.The lymphocytic infiltrates of minor salivary gland (MSG) lesions of Sjögren syndrome (SS) vary in grade and composition and are generally thought to develop in stepwise manner. Their progression over time is not well defined.Methods.We studied repetitive MSG biopsy specimens from 28 patients with primary SS.Results.The infiltration grade and prevalence of the major infiltrating cell types (T and B cells, macrophages, dendritic cells, natural killer cells) remained largely unchanged during a median 55 month biopsy time interval followup (quartiles 42–81).Conclusion.We found significant disease progression involving the development of mucosa-associated lymphoid tissue lymphoma in patients expressing adverse serologic prognostic factors, such as low serum C4 complement levels and cryoglobulinemia.