ABSTRACT
First described in 1975 by Lennert and Muller-Hermelink, progressively transforming germinal centers(PTGC) are follicular structures that are at least two to three times the diameter of a reactive follicle and are composed of small B lymphocytes with scattered centroblasts and follicular dendritic cells. PTGC may resemble the nodules of lymphocyte predominance Hodgkin's disease(NLPHD) and are often seen in lymph nodes involved by NLPHD. The distinction between NLPHD and PTGC are difficult because of their histologic similarities. Many authors performed an immunohistochemical study to determine whether there might be immunophenotypic differences between these two processes to aid in the differential diagnosis. We experienced PTGC in sibling and two cases is presented with the review of literatures.