[Cytophotometric method of determination of DNA content of neoplastic cells]

The content of DNA was investigated by the method of pulsed cytophotometry in cells of the following neoplasms: pulmonary cancer, benign lesions and cancer of the stomach, melanomas of the skin, malignant lymphomas and metastases of cancer into the lymphatic node. In the normal tissues and benign tumours the number of proliferating cells (DNA value of 3p, 4p) was not significant--from 2.0 to 5.0%. Polyploid cells were absent. In tumours the number of cells varied broadly--proliferating cells from 5.0 to 27,0%, polyploid cells from 9.0 to 40.0%. The use of the method of pulsed cytophotometry in prophylactic examinations is not effective, since in many cases changes could be detected only in single cells not identifiable on DNA-cytograms. Investigation of DNA content by the method of pulsed cytophotometry in a great number of tumour cells makes it possible to determine more accurately the character of the tumoral process, the level of differentiation of the tumoral tissue.