Mucosa-Associated Lymphoid Tissue

**Semantic type:** Tissue

**Definition:** Lymphoid tissue located beneath the mucosal epithelia of those mucosal surfaces that have contact with the external environment, such as the respiratory, digestive, and urinary systems. MALT consists of a collection of predominantly small lymphocytes, fewer larger, transformed lymphocytes, and plasma cells. It protects the body from pathogens that enter via the mucosa. MALT gives rise to a distinctive type of B-cell lymphoma that usually follows an indolent clinical course.

**Synonyms:** - Lymphoid Tissue, Mucosa-associated - MALT