[The leptomeningeal form of primary neuroectodermal tumor].

Brain neoplasms as primary leptomeningeal forms are rare, particularly if the case in point is primary neuroectodermal tumors (PNET). In the literature, there are only few reports on this topic. The authors describe one of such rare cases. A 21-years-old man was admitted to a hospital for complaints about headache. Brain computed tomography and magnetic resonance imaging (MRI) revealed internal hydrocephalus and slightly uniform meningeal thickening without the signs of space-occupying lesions. Ten months after ventriculoperitoneostomy, the patient suddenly developed tetraparesis and respiratory disorders. MRI showed a pronounced diffuse non-uniform leptomeningeal dissemination of a tumor. Open biopsy of the lesion in the projection of the right fissure detected PNET. The patient underwent a course of chemotherapy (CCNU, vincristine) and radiotherapy (total focal dose 45 Gy). Control MRI could not identify a pathological leptomeningeal signal.