[Flow cytometric studies of human brain tumors. Part 4: Metastatic tumors]

The distribution of DNA content in 12 cases of metastatic brain tumor, 6 cases of primary lung cancer and 6 cases of primary breast cancer were studied by flow cytometry. According to the pattern of DNA histogram, 12 specimens of metastatic brain tumors were classified into 3 types. Six cases of type I showed a sharp peak in 2C with large numbers of cells in 4C, 4 cases of type II showed the highest peak near 3C with a small peak in 2C, and 2 cases of type III showed a shift of the peak to the right near 4-5C. Type II and III seemed to have two different kinds of the cells which were mixed with normal brain cells or blood cells showing small peak in 2C and tumor cells showing the highest peak in 3C to 5C. Primary lung cancer and breast cancer were also divided into 2 types of DNA histogram, which were similar to those of metastatic brain tumors as type I and type II. Although there was no case of metastatic brain tumor having a DNA histogram of primary tumor in the same case, DNA patterns of metastatic brain tumors might be related to those of primary tumors because of the similarity of the histograms. It was difficult to disclose the primary sites or histological types of metastatic brain tumors from the type of DNA histograms but flow cytometric analysis revealed the characteristic patterns such as type II and III in metastatic brain tumors. We consider that these patterns might be of clinical diagnostic value in flow cytometric study.