A quantitative study of the size of benign and malignant lymphoid follicles.

The mean areas of lymphoid follicles have been determined in 20 specimens of malignant follicular (centrocytic-centroblastic) lymphoma, 15 specimens of reactive follicular hyperplasia and 10 palatine tonsils. In all of the benign specimens and whenever possible for those showing malignancy, the areas of both the whole follicles (including the "mantle" zones) and of the follicle centres were measured; this procedure was facilitated by means of the Reichert-Jung (Kontron) MOP-AMO3 image-analyser. Reactive lymph nodes were found to have larger mean follicle areas than centrocytic-centroblastic lymphomas; the areas of reactive follicles also show greater variation than do those of their malignant counterparts. In addition, the "mantle" zone is usually absent from malignant follicles but may account for up to 65.5% of the mean total follicle size in reactive lymph nodes and tonsils.