Defense mechanism and macroscopic tumor growth in lung tissue.

A total of 126 resection specimens from malignant lung tumors were cut into serial sections, and tumor volume and macroscopic growth pattern were computed. Four characteristic tumor growth patterns could be separated: Tumors growing in bizarre, irregular shapes; Tumors growing in spheroid shapes; Tumors growing in ellipsoid shapes; Tumors growing in mixed growth pattern. The immunologic response of the host tissue was analyzed grading the number of lymphocytes, plasma cells, macrophages in and at the boundary of the tumor tissue. Lymphocytic subpopulations were analyzed in 46 cases using monoclonal antibodies (BS3/BS4; T3, OKT4, OKT8, OKT11, OKT14). The majority of lymphocytes were T-lymphocytes and monocytes in cases with inflammatory response of host tissue. The ratio of inducer/helper subset (OKT4+) compared to suppressor/cytotoxic subset (OKT8+) was similar in expression as reported for circulating peripheral T-lymphocytes. The different growth patterns depend upon cell type of tumor, immunologic response of the host tissue, and tumor volume. The findings indicate that tumor progression into lung tissue is partly due to "localized metastatic growth" of different tumor cell subpopulations.