Lymph node from an ATxBM mouse (adult thymectomized, lethally irradiated, bone-marrow restored). The entire hematopoietic and immunological systems are restored to normal, except for the absence of T-cells. Primary follicles (PF) are present, but not germinal centers (therefore no secondary follicles). The normal cellularity of the diffuse cortex (DC), a T-cell area, is absent - only the pale-staining connective tissue is visible. The medulla (Med) appears normal.