Kinetic studies of circulating lymphocytes in malignant lymphatic disease using the impulse cytophotometer

Measurements of the DNA content of mononuclear cells in the blood of patients with malignant lymphatic disease were made. In one case of acute lymphoblastic leukaemia, a large fraction of large type of blasts were in S phase. In the blood of a patient with leukaemic transformation of lymphosarcoma, a population of aneuploid tumour cells with a high percentage of cells in S phase was recognized. The increase of DNA synthesizing cells in the blood of patients with malignant lymphoma was associated with activity of the disease. The fraction of DNA synthesizing cells was raised sharply during chemotherapy.