Comparative analysis of proliferative and genetic alterations in a primary chordoid meningioma and its recurrence using locus-specific probes and AgNOR

Abstract. Meningiomas are generally slow-growing benigntumours; however, recurrent cases are associated with a poorprognosis. As these tumours are commonly grouped accordingto their grade of malignancy, it is difficult to define tumour-specific alterations involved in their genesis and evolution.Genetic comparative studies of primary and recurrent tumoursare important for the identification of the chromosomal,genetic and proliferative alterations that are possibly involvedin the process of malignancy in this class of tumour. Weperformed interphase fluorescence in situ hybridization usingregion-specific probes comprising the genes MYCN , ERBB4 , CDH1 , ABR , ERBB2 and NF2 as well as AgNOR staining ina sample of primary and relapsed chordoid meningiomas. Sig-nificant differences were found in these samples regardingthe genes NF2 , MYCN , ABR and ERBB2 . Cell proliferationlevels also showed a significant difference. The resultssuggest the involvement of the MYCN gene in the evolutionof meningiomas.