Loss of heterozygosity studies in extracranial metastatic meningiomas.

Although most meningiomas are slow-growing tumours associated with favourable prognosis, they often present local recurrence after surgical treatment; by contrast, extracranial metastatic meningiomas are rare, occurring in less than 1% of the cases. Risk factors for distal spread remain largely unknown. We report three cases with lung or bone metastases from intracranial recurrent meningiomas. Loss of heterozygosity (LOH) analysis on 1p, 9p, 10q, 14q, and 22q was conducted in available primary, recurrent and metastatic lesions, showing the same LOH pattern in the distal metastases and in the intracranial meningioma. LOH at 1p, 14q and 9p, known to be associated with increased aggressiveness, were found. The results highlight the potential clinical relevance of integrating histopathological studies with molecular genetic analysis in the follow-up of patients with different types of meningiomas.