Many human tumors or tumor metastases are infiltrated or surrounded by mononuclear cells (MNC) consisting mainly of lymphocytes and macrophages [5, 31, 63]. The proportion of lymphocytes to macrophages in MNC infiltrates is variable from one tumor type to another [67]. The lymphocytic component of the infiltrate consists mainly of T cells, while B lymphocytes or natural killer (NK) cells are generally a minor population although, in some tumors, their numbers may be substantial [54, 60]. This type of chronic inflammatory infiltrate may be replaced in some tumors or in certain areas of tumors by a granulocytic (acute) infiltrate [44]. In fact, tumor-associated granulocytes have been credited with mediating tumor rejection through" cross-talk" via soluble mediators (cytokines) between tumor-infiltrating cells in the tumor microenvironment [14]. The role of MNC infiltrates in tumor growth or metastasis and their contribution to survival of patients with cancer have been subjects of considerable controversy in recent years. On the one hand, the presence of inflammatory cells at the site of tumor or its metastases has been taken as evidence of a host antitumor response [21, 59]. Also, on the strength of immunological data, tumor-infiltrating lymphocytes (TIL) have been considered to be not just inflammatory cells but rather antitumor effector cells that are recruited to the tumor as a part of the specific immune response. This has led to an intense search for autotumor-specific cytolytic T lymphocytes (CTL) among TIL in recent years [41]. On the other hand, it has been difficult to establish convincingly a positive correlation between the intensity, composition or localization in the tumor of lymphocytic infiltrates and a better prognosis