Primitive neuroectodermal tumors (PNETs) are a type of aggressive brain tumor that primarily affects children and young adults. They originate from primitive nerve cells in the central nervous system and can occur in various locations, including the brain and spinal cord. PNETs are classified as a subset of neuroectodermal tumors, which also includes medulloblastomas. These tumors are characterized by rapid growth and can lead to symptoms such as headaches, seizures, and neurological deficits. Treatment typically involves a combination of surgery, radiation therapy, and chemotherapy to manage the disease and improve outcomes for patients. Early diagnosis and intervention are crucial for better prognosis.