Angiogenesis in Non-Hodgkin's Lymphoma: An Intercategory Comparison of Microvessel Density
Abstract
Background: Angiogenesis has been shown to play an important role in the progression and aggressiveness of solid tumors and several hematologic malignancies. This study was aimed at assessing and comparing the angiogenesis in the form of microvessel density (MVD) in subtypes of non-Hodgkin lymphoma (NHL).
Methods: In this study, 64 cases of NHL diagnosed over a three-year period were included along with 15 lymph node biopsies of reactive lymphoid hyperplasia for comparison. NHLs were classified using the REAL classification and immunohistochemistry was performed for CD34 in all the cases. The CD34-stained sections were evaluated for “hot-spots”, where MVD was assessed and expressed as per mm^2. Appropriate statistical methods were applied for comparison between various subtypes of NHL.
Results: There were six cases of well differentiated lymphocytic lymphoma (SLL), 21 diffuse large B-cell (DLBCL), 15 follicular lymphoma, 10 lymphoblastic lymphoma, 7 MALToma and 5 peripheral T-cell lymphoma (PTCL). The mean MVD was highest in reactive lymphoid hyperplasia (191.92±12.16 per mm^2) compared to all NHLs. Among NHL, PTCL demonstrated the highest MVD (183.42±8.24) followed by DLBCL (149.91±13.68). On statistical analysis, a significant difference was found in MVD between reactive and all the individual lymphoma groups. SLL had significantly lower MVD than other lymphoma subtypes.
Conclusion: Angiogenesis, assessed by microvessel density, has shown significant differences among subtypes of NHL, especially the indolent types like SLL. The higher MVD in aggressive lymphomas like PTCL and DLBCL can potentially be utilized in targeted therapy with antiangiogenic drugs.