[Preliminary study of chromosome aberrations in pituitary adenoma].

Background & Objective: Pituitary adenoma is one of the most common intracranial benign tumor. This study was designed to seek the most suitable method for cytogenetic study of pituitary adenoma(PA), and then to analyze the genetic change of PA cell.

Methods: Twenty-five samples of primary PA were examined by R-banding through direct preparation(DP) and short-term culture(STC) to analyze genomic alterations.

Results: A karyotype of 17 samples was identified in 25 PAs by using the DP, whereas there was a karyotype of 21 samples by using the STC. An abnormal clonal karyotype was observed in 11 samples processed by the DP, however only 3 of 25 samples when processed by the STC. The common chromosomal alterations included gains of chromosomes X(6/25), 7(4/25), 8(2/25), 5(2/25) as well as losses of chromosomes 11(5/25), 9(4/25), 13(3/25), and the latter was observed predominantly in invasive PAs.

Conclusions: DP is one of the most suitable methods for the cytogenetic study of PA. There were multiple regions of chromosomes with copy number changes in PA including gains of chromosomes X, 7, 8, and losses of chromosomes 11, 9, 13. However, structural chromosome aberrations are not common. The loss of chromosome and the abnormality of structure may have some correlation with the biologic behavior of PA.