Cell kinetics in reticulum cell sarcoma

A cell kinetic study is described in a large, superficial reticulum cell sarcoma (stem cell type) of the scalp. A percentage-labeled mitosis curve was obtained following an intravenous injection of tritiated thymidine. No second wave of labeled mitoses was identified. The median intermotitic time was estimated to be 50 hours with component phases, G1—30 hours, S—14 hours, and G2—5 hours. The overall labeling index of the tumor was 3.6%. Labeling was confined to cells which on their cytologic appearance were regarded as the tumor cell population. The modal DNA content of the tumor cell population was measured with a microspectro-photometer on Feulgen-stained material. The modal DNA content was hyperdiploid. Growth rate measurements in 10 patients with reticulum cell sarcoma are presented and discussed in relation to the results of the study.