title: Malignant lymphoma of mucosa-associated lymphoid tissue.
abstract: Lymphomas of the gastrointestinal tract, salivary glands, lung and thyroid are grouped together as tumours arising in mucosa-associated lymphoid tissue. The great majority of them are of B-cell origin but distinctive T-cell lymphomas are also recognized in the gastrointestinal tract. These lymphomas tend to remain localized for prolonged periods but, whereas the B-cell group respond favourably to local therapy, the T-cell group are associated with severe morbidity and their overall prognosis is extremely poor. Accepted histological classifications of non-Hodgkin's lymphomas are difficult to apply to these tumours. In this paper their morphological features are reviewed; recent findings based on immunohistochemistry and DNA analysis are presented; and the biological behaviour of these tumours is discussed insofar as they offer insight into mucosal immunological mechanisms.
mesh_terms: D001402:B-Lymphocytes / Q000473:pathology; D006801:Humans; D007120:Immunochemistry; D008221:Lymphoid Tissue / Q000473:pathology*; D008223:Lymphoma / Q000276:immunology / Q000473:pathology*; D009092:Mucous Membrane / Q000473:pathology; D013274:Stomach Neoplasms / Q000276:immunology / Q000473:pathology; D013601:T-Lymphocytes / Q000473:pathology