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

Meningiomas are generally slow-growing benign tumours; however, recurrent cases are associated with a poor prognosis. As these tumours are commonly grouped according to 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 tumours are important for the identification of the chromosomal, genetic and proliferative alterations that are possibly involved in the process of malignancy in this class of tumour. We performed interphase fluorescence in situ hybridization using region-specific probes comprising the genes MYCN, ERBB4, CDH1, ABR, ERBB2 and NF2 as well as AgNOR staining in a sample of primary and relapsed chordoid meningiomas. Significant differences were found in these samples regarding the genes NF2, MYCN, ABR and ERBB2. Cell proliferation levels also showed a significant difference. The results suggest the involvement of the MYCN gene in the evolution of meningiomas.