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 lymphomas (B-NHLs) were investigated for counts of microvessels, total metachromatic mast cells (MCs) and MCs expressing tryptase, an angiogenesis-inducing molecule. Counts were higher in B-NHLs. When grouped according to the Working Formulation (WF) malignancy grades, they were significantly higher in low-grade B-NHLs vs. lymphadenopathies and intermediate-grade vs. low-grade 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 results suggest that angiogenesis in B-NHLs increases with their progression, and that MCs cooperate in its induction via the tryptase contained in their secretory granules.