Collections of lymphocytes occur at many places in the body. Everywhere there is a basic pattern, the lymphatic follicle. The follicle is a spherical collection of lymphocytes with a pale center known as germinal center, where the lymphocytes are more loosely packed.
The central cells are larger in size, stain less deeply, and divide more rapidly, than the peripheral cells. It expresses the cytogenic and defense functions of the lymphoid tissue and is commonly present inside the cortex.