Establishment of primary human meningiomas as subcutaneous xenografts in mice.

Meningiomas are the most frequently occurring benign central nervous system tumours. We determined whether a subcutaneous animal model of meningioma was feasible by implanting fresh meningioma tissue from six patients into 60 athymic (nude) mice, either as tissue blocks (38 mice) or as cell suspensions (22 mice). The tumour take-rates were 74% (block) and 50% (suspension), and the xenografts retained the original tumour grade and subtype morphology by light microscopy. Comparison of cell proliferation markers in xenografts and original tumours gave similar immunohistochemical score rates for Ki-67, but not for PCNA. With the exception of one atypical tumour surgical specimen, all tumours lacked p53 immunopositivity. Transmission electron microscopy of sections of tumour xenografts revealed ultrastructural features, including desmosomes and desmosome-like structures, characteristic of well-differentiated meningiomas. The xenografts grew progressively with a volume increase of more than 10-fold over 6-11 months and an apparent doubling time of 16 weeks. This study demonstrates the utility of the subcutaneous meningioma xenograft as a model for further biological and therapeutic studies.