Molecular progression in unusual recurrent non-pediatric intracranial clear cell meningioma.

We report a case of a recurrent clear cell meningioma (ccm) in the frontal lobe of the brain of a 67-year-old man. The patient developed three recurrences: at 3, 10, and 12 years after his initial surgery. Histopathology observations revealed a grade 2 ccm with positivity for vimentin and epithelial membrane antigen. Expression of E-cadherin was positive only in the primary tumour and in the first available recurrence. Fluorescence hybridization analyses demonstrated 1p and 14q deletions within the last recurrence. Multiplex ligation-dependent probe amplification studies revealed a heterozygous partial gene deletion, which progressed to total loss in the last recurrence. The last recurrence showed homozygous deletions in and . The gene was hypermethylated during tumour evolution. In this report, we show the genetic alterations of a primary ccm and its recurrences to elucidate their relationships with the changes involved in the progression of this rare neoplasm.