What is a Dysembryoplastic Neuroepithelial Tumor (DNET) or Ganglioglioma?

DNET or Ganglioglioma are slow growing tumors that are composed of both glial and neuronal elements.  They are very rare, accounting for less than 1-2% of brain tumors.  They typically develop from the supratentorial region, mainly the temporal lobe or frontal lobe.  Ganglioglioma are rarely located in other areas of the brain and spinal cord.  These tumors do not have a capacity to metastasize or spread beyond the primary site of origin.  DNET and Ganglioglioma are indolent, slow-growing tumors.  Very rarely ganglioglioma will undergo malignant transformation.  These tumors are mainly seen in children and young adults.  The average age of diagnosis is 9 years of age.  There is no known cause for DNET and Ganglioglioma.

What are the symptoms of Dysembryoplastic Neuroepithelial Tumor (DNET) or Ganglioglioma?
Due to their typical location within the frontal and temporal lobes, DNETs and Gangliogliomas almost always present with seizures.  Because DNET and Ganglioglioma are indolent, slow growing tumors, they often have a longstanding seizure history.  Ganglioglioma can develop in other areas of the brain or spinal cord and therefore can present with focal symptoms due to disturbance of the surrounding brain.  Ganglioglioma of the ventricle causes obstruction of the ventricle and symptoms of increased intracranial pressure (headache, vomiting, difficulties with balance, and lethargy).  Ganglioglioma of the brainstem and spinal cord can present with weakness, scoliosis, back pain or bowel and bladder dysfunction.

How is a Dysembryoplastic Neuroepithelial Tumor (DNET) or Ganglioglioma diagnosed?
Patients who have a brain tumor require an MRI of the brain and/or spine to further define the location of the tumor.  Patients who present with seizures undergo an EEG to locate the origin of the seizure.  Patients who have tumors located in the cerebral hemispheres will frequently undergo functional studies (functional MRI or magnetoencephalogram) to map out the important brain function located around the tumor, which will ultimately help the surgeon avoid eloquent functional areas of the brain at the time of surgical removal of the tumor.  A biopsy of the tumor is required to make the final diagnosis of a DNET or Ganglioglioma.

How is a Dysembryoplastic Neuroepithelial Tumor (DNET) or Ganglioglioma treated?
Surgery is the treatment for DNET and Ganglioglioma, with the goal to completely remove the tumor. The majority of DNET and Ganglioglioma are able to be completely removed safety. Complete tumor removal is associated with a very high cure rate. Surgical removal of the tumor also helps control seizures. In cases where partial resection is performed, these tumors tend to remain quiescent for years and possibly forever. If the tumor recurs, the recommended treatment is a second attempt at surgical removal of the tumor. The majority of patients treated for a DNET and Ganglioglioma are cured of their disease following the first surgery. There is no role for chemotherapy or radiation therapy in a typical DNET or Ganglioglioma.

About treatment for Dysembryoplastic Neuroepithelial Tumor (DNET) or Ganglioglioma at Children’s Hospitals and Clinics of Minnesota

Our cancer and blood disorders program consistently achieves excellent results ranking it in the top ten programs in the United States. Children’s Hospitals and Clinics of Minnesota treats the majority of children with cancer and blood disorders in Minnesota and provides patients access to a variety of clinical trials using ground-breaking new treatments. Through our renowned program, patients experience unparalleled family support, a nationally recognized pain management team, and compassionate, coordinated care.

If you are a family member looking for a Children’s neuro-oncologist, please call our clinic at 612-813-5940.

If you are a health professional looking for consultation or referral information, please call Children’s Physician 1-866-755-2121 (toll-free) and ask for the on-call hematologist/oncologist.

Additional information on Dysembryoplastic Neuroepithelial Tumor (DNET) or Ganglioglioma

For additional information, check out these web sites: