A mucosa-associated lymphoid tissue (MALT) type lymphoma (marginal zone B-cell lymphoma) from the palatine tonsil

The clinicopathologic and immunologic features of a low-grade B-cell non-Hodgkin's lymphoma that arose in the palatine tonsil are presented here. The histologic findings were similar to the mucosa-associated lymphoid tissue (MALT) type lymphoma described in the gastrointestinal tract and glandular tissues. The histogenesis, differential diagnoses and classification of these tumors are briefly discussed in the light of recent findings and proposals by the International Lymphoma Study Group (ILSG). A literature survey revealed that MALT-lymphomas are exceptionally rare in Waldeyer's ring. Pathologists should be aware of the possible occurrence, albeit rare, of this tumor when confronted with a low-grade B-cell lymphoma from Waldeyer's ring.