FIELD: medicine, oncology. SUBSTANCE: in patient's peripheral blood it is necessary to determine the values for percentage content of theophylline-sensitive lymphocytes, the ratio of lymphocytes to T-theophylline-resistant lymphocytes, spontaneous NBT-test, concentration of immunoglobulins A and M (g/l) and those of thymus function. If two or more positive values are present relative to a threshold level a malignant neoplasm should be predicted. If one positive value is either present or absent it is necessary to determine additionally the total amount of leukocytes, the percentage content of T-lymphocytes, O-cells, lymphocytes, monocytes, rod leukocytes, T-unmature, stable and theophylline-resistant lymphocytes, absolute number of segmented leukocytes, concentration of immunoglobulin G, phagocytic index and phagocytic number. Then diagnostic indices are calculated according to certain formula and if two or more positive diagnostic indices are present against a threshold level a malignant neoplasm is diagnosed, and if one positive index is either present or absent a benign pathology is diagnosed. EFFECT: higher accuracy of diagnostics and identification of malignant and benign neoplasms in patients with earlier oncopathology. 4 tbl
