Mucosa Associated Lymphatic Tissue (MALT)

This is the lymphoid tissue of the alimentary canal, upper respiratory passages, and urinary tract. It occurs in three forms: diffuse lymphatic tissue, solitary lymphatic nodules, and aggregates of lymphatic nodules. Aggregates of lymphocytes are most common in the small intestine (Peyer's patches) and in the vermiform appendix. Are these aggregates encapsulated or unencapsulated?

#117 Small intestine (H&E)

Within the lamina propria identify lymphatic nodules and note germinal centers of the active antigenic response.