High-grade non-Hodgkin's lymphoma of B-cell type. I. Histopathology.

One hundred and twenty-eight cases of high-grade malignant B-cell lymphoma were studied with a plastic re-embedding technique and classified according to the Kiel classification. The cytological details could be better recognized than in the original paraffin sections, thus permitting a more precise definition of the various lymphoma types. The entities centroblastic and immunoblastic lymphoma are more precisely defined and supplemented by the addition of several new variants. In contrast to the present Kiel classification we separate Burkitt's from lymphoblastic lymphoma. In all cases investigated, the B-cell nature of the tumour cells was proven by immunohistochemistry using monoclonal antibodies. The four entities of high-grade malignant B-cell lymphoma described in this paper are: (1) centroblastic lymphoma with four morphological variants (monomorphic, polymorphic, multilobated and centrocytoid); (2) immunoblastic lymphoma with three morphological variants (with or without plasmacytic differentiation, with many lymphocytes); (3) Burkitt's lymphoma and the closely related Burkitt's lymphoma-like lymphoma with plasmablastic differentiation; and (4) lymphoblastic lymphoma. Only the centroblastic lymphomas (in 17%) showed occasional follicular growth pattern, which further confirms the view that they are derived from germinal centre cells.