Follicular lymphoma: bcl-2 staining

Left panel: Neoplastic cells within the lymph node follicle from a patient with follicular lymphoma show strong immunostaining (brown color) for bcl-2. The lymphocytes in the thin mantles and the interfollicular regions also show bcl-2 reactivity. Right panel: In comparison, the germinal centers in a reactive follicle are bcl-2 negative, with the positive cells being located in the mantle and interfollicular regions.