Peripheral primitive neuroectodermal tumour (pPNET) of the cerebellopontine angle presenting in adult life

We report a case of a peripheral neuroectodermal tumour (pPNET) of the cerebellopontine angle of a 67-year-old woman. The patient's age at presentation was highly unusual. This case highlights the difficulties encountered, both clinically and pathologically, in securing the correct diagnosis of such a rare condition presenting in this relatively inaccessible area. The development of the nomenclature and classification of neuroectodermal tumours is traced. Recent advances in immunohistochemistry and genetic typing have shown the close relationship between pPNET and the previously difficult to classify Ewing's sarcoma and Askin's tumour.