Determination of vascularization of B-cell non-Hodgkin's lymphomas with four markers.

We evaluated the microvessel area (an index of angiogenesis) by using the factor VIII-related antigen (factor VIII-RA), and the expression of three components of the subendothelial basement membrane, namely: tenascin, laminin and type IV collagen. The four markers were assessed by immunohistochemical methods in 57 B-cell non-Hodgkin's lymphomas (B-NHL) and 28 benign lymphadenopathies. We found that microvessel area and the basement membrane markers had a different distribution pattern in relation to the histological type and degree of malignancy. In reactive and atypical lymphoid hyperplasias and in follicular low- and intermediate-grade B-NHL, microvessels were distributed within the interfollicular zones. By contrast, diffuse intermediate-grade and high-grade B-NHL were highly vascularized and microvessels were closely related to the neoplastic cells. Microvessel area was significantly associated with tenascin expression in all histological grades. Conversely, it was not correlated to laminin and type IV collagen expression, especially in diffuse intermediate-grade and high-grade B-NHL, where the expression of these markers was poor and fragmented. Our study suggests that angiogenesis and tenascin expression are associated phenomena in B-NHL, and that both increase with the malignancy grade. The prognostic value of angiogenesis and tenascin in B-NHL warrants further assessment in follow-up studies.