Association of tumor-associated macrophages of M2 subtype with outcome in follicular lymphoma.

8078 Background: Current methods used to prognosticate patients with follicular lymphoma (FL) include the Follicular Lymphoma International Prognostic Index (FLIPI) and tumor grade. However, they do not provide information on the biological and molecular features of FL. Recent data suggest that high tumor-associated macrophages (TAM) content may be an adverse prognostic factor in FL. However, TAM consists of two main subtypes, M1 and M2, with the former related to pro-inflammatory properties while the latter, anti-inflammatory functions. Currently, the prognostic impact of each individual subtype has not been elucidated and this may be more important than looking at TAM alone. Methods: Tumor specimens of 98 patients with FL diagnosed between 2005 and 2009 were investigated using immunohistochemistry and fluorescence in-situ hybridization (FISH) using break-apart FISH probes targeting BCL2, BCL6, MYC and IgH genes. Tumor specimens expressing a higher proportion of CD68+/CD163- in one high power field were ...