The natural history of benign lymphoepithelial lesion of the salivary gland in which there is a monoclonal population of B cells. A report of two cases.

In two patients, a diagnosis of benign lymphoepithelial lesion of the salivary gland was followed by the development of extrasalivary gland lymphoma after 10- and 9-year intervals, respectively. On review, immunohistochemistry revealed immunoglobulin light-chain restriction in the initial biopsy in each case and there was both morphological and immunohistochemical evidence linking the extrasalivary gland lymphoma with the initial lesion. It is argued that in the presence of a monoclonal B-cell population, a diagnosis of benign lymphoepithelial lesion is inappropriate. These patients fulfill the criteria for a diagnosis of low-grade B-cell lymphoma of mucosa-associated lymphoid tissue and should be treated accordingly.