Primitive neuroectodermal tumor presenting with diffuse leptomeningeal involvement in a 55-year-old woman: a case report and brief summary of current diagnostic tests and treatment.

Primitive neuroectodermal tumors (PNETs) are typically present as masses in children and adolescents, but rarely in adults. Diagnoses, management strategies, and prognostication factors are not well established in adult cases of PNETs. We describe the case of a central nervous system PNET diagnosed in a 55-year-old woman presenting with a sudden onset of symptoms consisting of increased intracranial pressure and findings of diffuse leptomeningeal enhancement and a small medullary lesion seen on MRI. Amongst the small database of PNETs diagnosed in adults, our case report stands out as one of few cases describing a primarily leptomeningeal PNET diagnosed on biopsy. We also review the literature on PNETs presenting with diffuse leptomeningeal disease and the treatment of PNETs in the adult population.