The heterogeneity of follicular center cell lymphomas. I. Cytohistologic, immunologic, and enzymehistochemical aspects.

Histologic material from 44 patients with follicular center cell lymphomas with a follicular growth pattern was divided into five groups on the basis of the predominating neoplastic cell type(s), i.e., small centrocytes with occasional centroblasts (SCC), centrocytes and few (CBCC/A) or many (CBCC/B) centroblasts, small and large centrocytes (SLCC), and small and large centroblasts (SLCB). Histologic, immunologic, and enzymehistochemical parameters as observed in these groups were compared, and follow-up material and material obtained during staging procedures were studied. Immunologic and enzymehistochemical findings confirmed both the B-cell origin and the neoplastic nature of the lymphomas, but did not yield relevant differences between the various groups. The groups with a predominance of small centrocytes or of small centrocytes and centroblasts showed the most prominent follicular growth and early dissemination to bone marrow and spleen. Histologic transformation in these groups was characterized by an increase in the number of centroblasts and a more diffuse growth pattern. The groups composed of small and large centrocytes or centroblasts tended to a more diffuse growth and had later dissemination and no histological transformation.