COVID-19 Updates: Latest Information for Parents


A to Z: Primitive Neuroectodermal Tumor (PNET)

A to Z: Primitive Neuroectodermal Tumor (PNET)

May also be called: Medulloblastoma; Posterior Fossa PNET; Supratentorial PNET; Pineoblastoma

Primitive neuroectodermal (PRIM-ih-tiv nur-oh-ek-tuh-DERM-ul) tumors, or PNETs, are tumors that can happen anywhere in the brain or spine.

More to Know

A primitive, or undifferentiated, nerve cell is a cell in the brain or central nervous system that doesn’t have a specific function. Primitive cells are often malignant (meaning they are often cancerous), and start to grow out of control. Doctors call the resulting tumors primitive neuroectodermal tumors, or PNETS.

Types of PNETs include medulloblastoma, posterior fossa PNET, supratentorial PNET, and pineoblastoma. All of these tumors are able to metastasize (spread) through the cerebrospinal fluid that surrounds the brain and the spinal cord.

PNET symptoms generally depend on the size and location of the tumor, but common symptoms include:

  • headaches, nausea, and vomiting (especially in the morning) caused by increased pressure in the head
  • weakness in the arms and legs
  • vision problems
  • seizures
  • trouble with balance and coordination

PNETs require aggressive treatment, including surgery, chemotherapy, and radiation therapy.

Keep in Mind

PNETs are serious tumors that require a lot of treatment, but recent medical advances have made a cure possible for most of children who have them.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.