Chromosomal characteristics of human pituitary adenomas.

Abstract

The chromosomes in 7 human pituitary adenomas were studied in fixations directly from the tumours. A normal, diploid stemline was only found in two adenomas; the other 5 tumours had near-diploid and near-triploid stemlines, and one adenoma of the diploid group had a marker in its stemline. In ordinary chromosome groups the deviations engaged C and F chromosomes, particularly. This pattern was different from that found in meningomas and neurinomas. The common occurrence of chromosomal abnormalities in these three benign tumor types was in contrast to the usually normal, diploid stemline observed in other benign lesions in man (precancerous conditions excluded). Thus, the present study demonstrates that some benign human tumours may show chromosomal abnormalities without any obvious relation to a malignant transformation. Furthermore, these deviations seems to have different characteristics in different benign tumour types.