Characterization and frequency distribution of lymphoreticular infiltrates in axillary lymph node metastases of invasive ductal carcinoma of the breast.

One hundred and seventy-five axillary lymph nodes containing metastatic deposits from 46 invasive ductal carcinomas of the breast were evaluated histologically and immunohistologically. The study yielded the following results: (1) tumor-infiltrating lymphoreticular cells preferentially accumulated in the stromal bands; the tumor foci generally showed a considerably lower degree of infiltration; (2) in most cases, monocytes/macrophages (Mono 1+) represented the overwhelming majority of tumor-infiltrating cells; (3) next in frequency were T-lymphocytes (Leu-1+), especially CD4+ lymphocytes (Leu-3a+), while CD8+ lymphocytes (Leu-2a+) mostly occurred only in moderate numbers; (4) B-lymphocytes (To15+), plasma cells, natural killer cells (Leu-7+), tissue mast cells, and T-accessory reticulum cells (OKT 6+) were observed mostly in low or very low numbers, while eosinophils were nearly absent and B-accessory reticulum cells (Ki-M4+) were totally absent from the lymphoreticular infiltrates. Definite conclusions regarding the functional properties of the tumor-infiltrating cells cannot be drawn from an immunohistologic analysis in situ alone, but the preferred localization of most tumor-infiltrating cells in the stroma does not support an intensive interaction between the host defenses and the metastatic tumor.