The Immunohistology of Follicle Lysis in Lymph Node Biopsies

Follicle lysis is a characteristic alteration of B cell follicles described recently in lymph node biopsies from homosexual men. It consists of disruption of germinal centers by aggregates of small mature lymphocytes variably associated with erythrocyte extravasation. We studied the immunohistology of follicle lysis identified in lymph node biopsies from 1 1 homosexual men. The results indicate that follicle lysis has two principal immunohistologic features: (1 ) intrafollicular aggregates of small lymphocytes predominantly of polytypic mantle B cell phenotype or Xi, and (2) disruption of the normal. unified follicular meshwork of R4/23 dendritic reticulum cells by these B cell aggregates. These structural I N A RECENT REPORT concerning the histopathology of lymphadenopathy in homosexual men, we described a characteristic alteration of germinal centers, termed “follicle lysis,” in approximately one-half of the biopsies exhibiting florid reactive follicular hyperplasia.’ This consisted of disruption of germinal centers by clusters of small mature lymphocytes with or without associated extravasation of erythrocytes. Similar features have been commented on in only a few of the reports that have appeared concerning lymphadenopathy in homosexual men.2’3 In this study, we describe the immunohistology of follicle lysis and discuss its possible significance.