Homogeneously staining regions in direct preparations from human neuroblastomas.

Previous descriptions of homogeneously staining regions in human neuroblastomas have been in karyotypes obtained from established cell lines. We now report homogeneously staining regions in direct preparations from two human neuroblastomas. In one of the cases, the homogeneously staining region identified in the primary tumor was also found in metastases to bone marrow and pleural fluid. The homogeneously staining region is, therefore, not an artifact of growth in vitro.