A Rare Initial Presentation of Primary Diffuse Leptomeningeal PNET in a 10-Year-Old-Male

Primary leptomeningeal primitive neuroectodermal tumors (PNETs) are extremely rare childhood central nervous system malignancies harboring a very poor prognosis. There is no consensus treatment for these tumors to date. We report a case of a 10-year-old male who presented with mental status change, hydrocephalus, intracranial and spinal diffuse leptomeningeal enhancement without a primary mass upon cranial imaging and a negative initial biopsy until five months into his presentation. He responded significantly well to initial chemotherapy and radiotherapy.