The Relationship Between Macrophages and Microvascular Density in the Microenvironment of Diffuse Large B-cell Lymphoma and Clinical Data

Diffuse large B-cell lymphoma, NOS (DLBCL, NOS) is the most common subtype of non-Hodgkin lymphomas. About one-third of patients are resistant to standard treatment, highlighting the need for new therapies. Our study aimed to predict the prognosis of DLBCL, NOS patients by analyzing tumor-infiltrating macrophages and vascular structures, and to assist in identifying new therapeutic strategies targeting the tumor microenvironment. In our study, we retrospectively evaluated 122 excisional biopsy samples diagnosed with DLBCL, NOS from the archives of the pathology department of our hospital between 2006 and 2022. Patient data, including age, gender, localization, extranodal involvement, relapse status, Ann Arbor stage, and International Prognostic Index (IPI) score, were collected and recorded. Immunohistochemically, microvascular density (MVD) was assessed using CD31, and tumor-associated macrophages (TAMs) were evaluated with CD68 and CD163. The expression levels of CD68 and CD163 were significantly higher in cases with high IPI scores, advanced Ann Arbor stages, or extranodal disease (CD68; p = 0.028, p < 0.001, p = 0.002, CD163; p = 0.017, p = 0.002, p = 0.001). No statistically significant differences were observed between MVD and gender, extranodal disease, relapse status, IPI score, Ann Arbor stage, or the Hans algorithm. Furthermore, no statistically significant correlation was found between overall survival and the expression levels of CD68 and CD163, or MVD. Our findings suggest that (TAMs) and vascular structures, which are components of the tumor microenvironment, serve as prognostic factors in DLBCL, NOS. The tumor microenvironment is expected to have a high potential for combined or alternative therapeutic strategies to be added to classical chemotherapy.