Cytogenetic characterization of skull base tumors using spectral karyotyping and g-banding

Abstract

Problem: The advance of novel molecular cytogenetic methods, among them spectral karyotyping (SKY), has opened new avenues for characterizing the chromosomal complexity of human malignancies and for the discovery of new genes related to tumorigenesis. The aim of our study was to investigate the spectrum of karyotypic changes in various skull base tumors (SBT), to determine whether benign tumors are cytogenetically different from malignant tumors, to compare the impact of radiotherapy on the karyotype, and to evaluate the possible clinical significance of chromosomal findings. Methods: A chromosomal analysis was performed on primary short-term cultures, from tissue immediately removed during surgery. We used SKY analysis and the G-banding technique for cytogenetic characterization and karyotyping of SBT. Results: A series of 50 SBT (36 malignant and 14 benign tumors) were successfully analyzed and evaluated for clinical, morphological, and cytogenetic features. Clonal chromosomal aberrations were found in 53% of the malignant and 16% of the benign tumors. Novel chromosomal aberrations were characterized in squamous cell carcinoma, undifferentiated carcinoma, porocarcinoma, malignant Schwannoma, teratoma, and chordoma of the skull base. We found significant association between multiple chromosomal abnormalities and poor clinical outcome. Significance: To our knowledge, this is the first series of complete cytogenetic analysis of SBT. The results provide valuable information for clinical-molecular diagnosis of SBT and the mechanism of tumorigenesis. Support: Israeli Cancer Association