The mucosa-associated lymphoid tissue (MALT) (also called mucosa-associated lymphatic tissue) is the diffuse system of small concentrations of lymphoid tissue found in various sites of the body such as the gastrointestinal tract, thyroid, breast, lung, salivary glands, eye, and skin.

MALT is populated by lymphocytes such as T cells & B cells, as well as plasma cells and macrophages, each of which is well situated to encounter antigens passing through the mucosal epithelium. In the case of intestinal MALT, M cells are also present, which sample antigen from the lumen and deliver it to the lymphoid tissue.

[edit] Components

The components of MALT are sometimes subdivided into the following:

• GALT (gut-associated lymphoid tissue. Peyer's patches are a component of GALT found in the lining of the small intestines.)
• BALT (bronchus-associated lymphoid tissue)
• NALT (nose-associated lymphoid tissue)
• LALT (larynx-associated lymphoid tissue)
• SALT (skin-associated lymphoid tissue)
• VALT (vascular-associated lymphoid tissue. A newly recognized entity that exists inside arteries; its role in the immune response is unknown.)
• CALT (conjunctiva-associated lymphoid tissue in the human eye)

[edit] Role in disease

MALT plays a role in regulating mucosal immunity. It may be the site of lymphoma, usually non-Hodgkin lymphoma. A specific entity is the MALT lymphoma linked to Helicobacter pylori in the stomach.

[edit] External links

• MALT resource page - Patients Against Lymphoma
• Maltoma

v • d • e Immune system: Lymphatic system (Lymph, Lymphocytes, Lymph vessels) (TA A13.1-2, GA 8) Primary Bone marrow · Thymus (Hassall's corpuscles) Secondary Spleen (process blood) structural: Hilum · Trabeculae Red pulp (Cords of Billroth, Marginal zone) White pulp (Periarteriolar lymphoid sheaths, Germinal center) blood flow: Trabecular arteries · Trabecular veins Lymph nodes (process extracellular fluid) lymph flow: Afferent lymph vessels · Cortical sinuses · Medullary sinuses · Efferent lymph vessels T cells: High endothelial venules B cells: Primary follicle/Germinal center · Mantle zone · Marginal zone layers: Capsule/Trabeculae · Subcapsular sinus · Cortex · Paracortex · Medulla (Medullary cord) · Hilum MALT (process mucosa) GALT · Peyer's patches · Germinal center lymphatic organ navs: anat, physio, lymphatic disease/splenic disease/thymus disorders/thymus neoplasia/vascular tumors, proc