Tumor-associated macrophages in lymphoma: From mechanisms to therapy

Lymphoma is a common hematologic malignant tumor that originates from lymph nodes or other lymphoid tissues. The tumor microenvironment (TME) plays an indispensable role in tumorigenesis, tumor development, metastasis, relapse, and drug resistance. Macrophages, which are considered as critical immune cells in the TME, influence the development of tumors. In particular, M2-like tumor-associated macrophages (TAMs) promote lymphoma growth and worsen patient prognosis. Owing to their important roles in lymphoma, TAMs hold promise as biomarkers or targets for tumor immunotherapy. In this review, we summarize the origin, recruitment, polarization, function, and mechanism of action of TAMs in lymphoma to identify potential therapeutic targets and other strategies for patients with lymphoma.