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. These tumors can spread to the fluid that surrounds the brain and spinal cord.

More to Know

Primitive neuroectodermal tumors develop from immature nerve cells in the brain. These primitive cells are often cancerous, and can start to grow out of control.

Types of PNETs include:

• medulloblastoma
• posterior fossa PNET
• supratentorial PNET
• pineoblastoma

Symptoms of a PNET often depend on the size of the tumor and where it is, 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 need a lot of treatment. But recent medical advances have made a cure possible for many of the children who have them.

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