Patterns of the early, gross chromosomal changes in malignant human gliomas.

Chromosomal findings by banding in 12 malignant human gliomas demonstrated clearly that simple numerical changes are the primary gross deviations in gliomas. So far, these numerical primary deviations fall into three different groups: (1) gliomas showing a loss of a gonosome, (2) tumors with gains of No. 7 (and at the same time often also losses of No. 10), and (3) cases with losses of No. 22. The further evolution seems to be characterized by a variety of partly nonrandom numerical and also structural changes. The aberration of double-minutes (DMs), found in half of our cases, might be such a non-random anomaly. If (as suggested by recent reports in the literature) the DMs correlate with activation of an amplified oncogene, then this anomaly might indicate a special subsequent step in oncogenesis or it might even in some cases represent an alternative to the seemingly primary numerical deviations and precede them.