This report describes a malignant neoplasia of the pineal region in a 65-year-old woman who presented with symptoms of intracranial hypertension and dissemination to CSF with radiologically documented lumbar intradural localizations. The histological examination of the lesion showed fragments of a cystic malignant neoplasia with epithelial elements resembling squamous cell carcinoma. We excluded the possibility of a cerebral metastasis from a squamous cell carcinoma arising in the genital or gastrointestinal tract, lung and skin. We propose this unique report for cyto- histological correlation and, as suggested in the American and Japanese literature, we discuss the hypothesis of the development of a squamous cell carcinoma arising from the malignant degeneration of a cerebral epidermoid cyst and we show by cytological examination of the CSF the exceptional presence of malignant cells and by lumbar MRI their intradural localizations.