Mantle zoneThe mantle zone of a lymphatic nodule is an outer ring of small lymphocytes surrounding a germinal center.It is also known as the "corona".It contains transient lymphocytes.It is the location of the lymphoma in mantle cell lymphoma.PathologyMantle zone expansion may be seen in benign, such as Castleman disease, and malignancy, i.e., Mantle cell lymphoma. Tcl-1 is expressed in the mantle zone.