Brain changes and survival of animals with tumors implanted in the brain.

The effects of tumor cells implanted into the brain of animals on survival rates and gross and microscopic brain changes have been ascertained. Walker carcinosarcoma 256 cell suspensions were injected at several brain sites in rats and leukemia L1210 and P388 and Ehrlich ascites tumor cells, intracerebrally into BDF1 mice. Such neoplasms provided for rapid and rather predictable growth increments. The survival rates were dependent on the number of cells introduced, those receiving the higher counts succumbing first. The brains of the animals revealed fairly discrete space-occupying lesions and neurological symptoms became apparent only hours before death due to intracranial pressure.