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Central Nervous System (CNS) Embryonal Tumor and Tumors of Uncertain Differentiation Treatment

Many brain and spinal cord tumors are rare and aggressive but difficult to categorize. In the past, these tumors have gone by several names, including:

  • Primitive neuroectodermal tumors (PNETs)
  • Malignant neuroepithelial tumors
  • High-grade neuroepithelial tumors
  • Rare CNS embryonal tumors
  • Mesenchymal tumors
  • CNS primary sarcomas

If your child has been diagnosed with any of these, you have come to the right place. We will guide you to a better understanding of their diagnosis.

These tumors look similar under the microscope. But we have recently learned that the molecular changes (genetic mutations) that make these tumors grow are quite different. Most of the new names are now defined by the molecular features. This may be confusing. Also, the typical age at diagnosis, the prognosis, and the treatment plan may differ based on the molecular markers.

These tumors are all aggressive. Each responds differently to treatment. We are redefining how to treat these tumors. We intensify and change the therapy for the most aggressive tumors. For those with a better prognosis, we can decrease therapy. This reduces side effects.

Types of CNS embryonal tumors and tumors of uncertain differentiation

These tumors are now categorized to include multiple types based on the molecular or genetic changes (mutations) that caused the tumor to develop.

Because there are different types, molecular testing must occur on the tumor to get the correct diagnosis and determine the best treatment.

Types may include:

  • Astroblastoma, MN1 altered
  • Atypical teratoid rhabdoid tumor (ATRT)
  • CIC rearranged sarcoma
  • CNS embryonal tumor, not otherwise specified/not elsewhere classified (NOS/NEC)
  • CNS Ewing sarcoma
  • CNS neuroblastoma, FOXR2 activated
  • CNS tumor with BCOR ITD
  • Embryonal tumor with multilayer rosettes (ETMR)
  • Intracranial mesenchymal tumor
  • Pineal parenchymal tumors, which include:
    • Pineoblastoma
    • Pineal parenchymal tumor of intermediate differentiation (PPTID)
    • Papillary tumor of the pineal region (PTPR)
    • Pineocytoma
    • Desmoplastic myxoid tumor of the pineal region.
  • Primary intracranial sarcoma, DICER1-mutant

Treatment of CNS embryonal tumors and tumors of uncertain differentiation

Treatment may include surgery followed by radiation and chemotherapy:

  • Surgery removes part or all of the tumor tissue. This takes out cancerous tissue and helps determine the type of tumor.
  • Radiation is an important part of treatment for all of these tumors. The dose, location, and timing of radiation will depend on many factors. These include your child’s age, type of tumor, and if it has spread to other parts of the brain or spine.
  • Chemotherapy (chemo) is important in the treatment of these tumors. The exact type of chemotherapy and the length of treatment will depend on your child’s age and type of tumor.

CNS embryonal tumors and tumors of uncertain differentiation prognosis 

The prognosis for different embryonal tumors varies greatly. It depends on:

  • The specific type and genetic mutations
  • If the tumor was totally removed (resected)
  • If the tumor is just in 1 area or if it has spread
  • The child’s age
  • If the tumor was newly diagnosed or has returned (recurred)

CNS embryonal tumors and tumors of uncertain differentiation clinical trials 

Patients with these tumors take part in clinical trials that use the most advanced diagnosis tools and treatments available. Our goal is to give each child the best treatment with the lowest number of side effects.

Our doctors and scientists work together to find better ways to treat patients. In many cases, new treatments are being developed right here on the St. Jude campus.

We also take part in trials developed by the Children’s Oncology Group (COG) and the Pediatric Brain Tumor Consortium (PBTC). Many of our doctors and scientists play key roles in developing these large studies. They happen at centers across the United States.

If a clinical trial is unavailable, your child may have therapies commonly used to treat patients with brain or spine tumors. These are often referred to as “standard” treatment. If they do not work, patients may be eligible to enter clinical trials using new therapies or existing therapies in a new way.

Learn more about clinical research at St. Jude.

PEPN2121: Tiragolumab and Atezolizumab for SMARCB1- or SMARCA4-deficient Tumors

Study goal:

Tiragolumab and atezolizumab will be used to treat pediatric and young adult patients with SMARCB1- and SMARCA4-deficient tumors.


Phase 1: ages 1–17 years; Phase 2: age 18 and older

CNS embryonal tumors and tumors of uncertain differentiation care at St. Jude 

St. Jude provides the highest quality of care for our patients with CNS embryonal tumors and tumors of uncertain differentiation:

  • We bring together medical experts and specially trained staff to care for your child. We also partner with expert brain surgeons (neurosurgeons) at Le Bonheur Children’s Hospital.
  • We have a special team that helps understand the makeup of the tumor. This team includes doctors and scientists who study:
    • Cancer cells
    • How the cancer happened
    • Current medicines and treatments to kill cancer cells
    • What makes cancer cells grow and what new medicines can stop them
    • New medicines and other therapies to improve how treatments work
  • Our brain and spine tumor clinical trials have led to better therapies in children. These improvements include lower-dose therapies, targeted therapy, and proton therapy. These treatments kill cancer cells while sparing healthy cells. They may lessen side effects that affect brain function after treatment for some types of brain tumors.
  • The St. Jude Proton Therapy Center is the first center in the world that treats only children with this therapy.
  • Along with the treatment studies constantly being developed at St. Jude, the staff also treats patients on studies developed by the Children’s Oncology Group (COG), the Pediatric Brain Tumor Consortium (PBTC), and the Pacific Pediatric Neuro-Oncology Consortium (PNOC). Many St. Jude staff members play key roles in developing these studies. These are large trials carried out at multiple centers across the United States. 

More reasons to choose St. Jude for care include:

  • We are consistently ranked among the best childhood cancer centers in the nation by U.S. News & World Report.
  • At St. Jude, we have created an environment where children can be children and families can be together.
  • We lead more clinical trials for childhood cancer than any other hospital in the U.S. 
  • St. Jude is the only National Cancer Institute–designated Comprehensive Cancer Center just for children. A Comprehensive Cancer Center meets rigorous standards for research to develop new and better approaches to prevent, diagnose, and treat cancer.
  • The nurse-to-patient ratio at St. Jude is about 1:3 in hematology and oncology and 1:1 in the Intensive Care Unit.
  • Patients may be able to get expert, compassionate care and treatment closer to their homes through our St. Jude Affiliate clinics.
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Seeking treatment at St. Jude

Patients accepted to St. Jude must have a disease we treat and must be referred by a physician or other qualified medical professional. We accept most patients based on their ability to enroll in an open clinical trial.

How to seek treatment

Physician / Patient Referral Office

Call: 1-888-226-4343 (toll-free) or 901-595-4055 (local)  | Email:
Fax: 901-595-4011 | 24-hour pager: 1-800-349-4334

Contact the Brain Tumor Team directly:

Submit brain tumor contact form

Contact the Surgery Team directly:


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