Angiogenesis and mast cell density with tryptase activity increase simultaneously with pathological progression in B-cell non-Hodgkin's lymphomas

Node biopsies of 16 benign lymphadenopathies and 72 B-cell non-Hodgkin's ly mphomas (B-NHLs) were investigated for counts of microvessels, total metach romatic mast cells (MCs) and MCs expressing tryptase, an angiogenesis-induc ing molecule. Counts were higher in B-NHLs. When grouped according to the W orking Formulation (WF) malignancy grades, they were significantly higher i n low-grade B-NHLs vs. lymphadenopathies and intermediate-grade vs. low-gra de tumors and there was a further increase in the high-grade tumors. A high correlation was demonstrated in all groups of tissues between microvessel counts and both total metachromatic and tryptase-reactive MCs. These result s suggest that angiogenesis in B-NHLs increases with their progression, and that MCs cooperate in its induction via the tryptase contained in their se cretory granules. (C) 2000 Wiley-Liss, Inc.