Dysembryplastic Neuroepithelial Tumor (DNT)

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    This group of tumors occurs in the tissues that cover the brain and spinal cord. They occur in the cerebrum, the part of the brain that controls thought, movement and sensation. Learn about dysembryoplastic neuroepithelial tumors in children and find information on how we support and care for children with DNT before, during, and after treatment.

The Brain Tumor Center at Dana-Farber/Boston Children's Cancer and Blood Disorders Center cares for children with many different types of common and rare brain and spinal tumors, including astrocytomas, medulloblastomas, ependymoma, glioblastomas, and primitive neuroectodermal tumors (PNET).

Your child will receive care from some of the world’s most experienced pediatric brain tumor doctors and internationally recognized pediatric subspecialists.

Our team works closely together to develop a care plan that offers your child the highest possible quality of life after treatment, and takes the needs of your child and your family into account.

Children treated at the Brain Tumor Center have access to some of the most advanced diagnostics and therapies, including:

  • Quick and accurate diagnosis from our dedicated pediatric neuropathologist
  • Access to advanced technologies like the intraoperative MRI, which allows our neurosurgeons to see detailed images of the brain during surgery
  • Advanced pediatric radiation oncology services, including targeted radiosurgery and low-dose radiation therapy that minimize exposure to radiation
  • Outpatient and oral chemotherapy, which may minimize the number of times your child will need to visit the hospital
  • Innovative therapies offered through clinical trials at Dana-Farber, Boston Children's Hospital, and nationally
  • Specialized programs for the treatment of low- and high-grade gliomas, and medulloblastoma

Thanks to refined surgical techniques and improved chemotherapy and radiation therapy, the majority of children with brain and spinal cord tumors are now long-term survivors. However, they may face physical, social, and intellectual challenges that require specialized care.

Learn more about our Brain Tumor Center.

Information for: Patients | Healthcare Professionals

Dysembryplastic Neuroepithelial Tumor (DNIT)

Overview

If your child has been experiencing seizures that don’t respond to medication, a possible cause may be a dysembryoplastic neuroepithelial tumor (DNT). This is a rare, benign type of tumor that occurs in the tissues that cover the brain and spinal cord. The outlook for a child with DNT is generally good.

As you read further below, you will find general information about dysembryoplastic neuroepithelial tumors (DNT).

How Dana-Farber/Boston Children's Cancer and Blood Disorders Center Approaches DNT:

Your child will be seen through Dana-Farber/Boston Children's Cancer and Blood Disorders Center, an integrated pediatric oncology program through Dana-Farber Cancer Institute and Boston Children's Hospital that provides — in one specialized program — all the services of both a leading cancer center and a pediatric hospital.

Our pediatric neuro-oncology, neurosurgical and neurology specialists at Dana-Farber/Boston Children's offer:

  • technological advances, such as the intra-operative MRI, which allow our pediatric neurosurgeons to “see” the tumor as they operate with MRI scans. This allows them to remove as much of the tumor as possible.
  • treatment with the best standard of care, including neurosurgery, radiation therapy and chemotherapy
  • access to unique Phase I clinical trials run by our own investigators, Children’s Oncology Group and the Pediatric Oncology Experimental Therapeutics Consortium

Through the Stop and Shop Neuro-Oncology Outcomes Clinic at Dana-Farber Cancer Institute, your child will be are able to meet with his entire care team at the same follow-up visit.

  • Our pediatric brain tumor survivorship clinic is held weekly.
  • In addition to meeting with your pediatric neuro-oncologists, neurologist and neurosurgeon, your child may also see one of our endocrinologists or alternative/complementary therapy specialists.
  • School liaisons and psychosocial personnel from the pediatric brain tumor team are also available.
  • If your child needs rehabilitation, he may also meet with speech, physical, and occupational therapists during and after treatments.

In-depth

Who is at risk for a DNT?

A DNT usually begins in children and teenagers who are 20 years old or younger.

What are the symptoms of dysembryoplastic neuroepithelial tumor (DNT)?

While each child may experience symptoms differently, and symptoms may vary depending on the size and exact location of the tumor, the most common symptom for DNT is the presence of seizures that are difficult to control with anti-seizure medication. In fact, it’s not uncommon for children to have their first seizure before age 10 and then continue to experience them for several years before the diagnosis is made.

DNT tumors are found in the cerebrum, which is the part of the brain that controls thought, movement and sensation, so your child may experience other symptoms that relate to those functions.

What is a DNT made of?  

These tumors consist of different types of abnormal cells including:

  • oligodendrocytes (cells that provide support and nourishment for cells that transmit nerve impulses)
  • neurons
  • astrocytes (connective tissue cells)

Tests

If your child’s doctor suspects that he may have a dysembryoplastic neuroepithelial tumor, she may order diagnostic tests including:  

  • neurological exam – a test of your child’s reflexes, muscle strength, eye and mouth movement, coordination and alertness
     
  • computerized tomography scan (also called a CT or CAT scan) – This is a diagnostic procedure that uses x-rays and computer technology to produce cross-sectional images (often called slices), of the brain and spinal cord. A CT scan will identify low-density dysembryoplastic neuroepithelial tumors.
     
  • magnetic resonance imaging (MRI) – This is a procedure that uses large magnets, radiofrequencies and a computer to produce detailed images of your child’s organs and other bodily structures. It can help confirm the presence of a DNT and distinguish it from other types of tumors.
     
  • immunohistochemical and ultrastructural studies - lab-based studies that can confirm the origin of DNT and help your child’s doctor determine the best treatment

Treatment and care

At Dana-Farber/Boston Children's, we know how difficult a diagnosis of a brain tumor can be, both for your child and for your whole family. That’s why our physicians are focused on family-centered care: From your first visit, you’ll work with a team of professionals who are committed to supporting all of your family’s physical and psychosocial needs.

The most common treatment for DNT is to remove the tumor surgically. Because it is a benign tumor, and prognosis is good even if not the entire tumor is not removed, radiation and chemotherapy are not used. 

What’s the long-term outlook for my child?  

The outlook for dysembryoplastic neuroepithelial tumors (DNT) is uniformly good, regardless of how much of the tumor is removed.

Research and innovations

A hopeful future

Treatment for brain tumors in children has progressed tremendously in the last decade:

  • New tools are being used to help doctors diagnose tumors sooner and with more accuracy.
  • Radiation therapy and chemotherapy are increasingly targeting tumors more accurately and effectively while keeping clear of healthy brain cells and tissue.
  • A successful new surgical technique is the intra-operative MRI, which gives surgeons a three-dimensional picture of the tumor so they can remove the cancer while leaving other parts of the brain relatively untouched.
Research and clinical trials

Our program offers unique access to a range of clinical trials in which your child can receive the newest brain tumor treatments. Through this research, our physicians work to improve current therapeutic approaches and outcomes for many hard-to-treat pediatric brain tumors. Dana-Farber/Boston Children's oversees New England’s most active pediatric oncology clinical research program; it provides access to unique clinical trials for patients with newly diagnosed, relapsed or refractory brain tumors. We are:

  • New England’s Phase I Children’s Oncology Group referral center, a Pediatric Oncology Experimental Therapeutics Investigator Consortium member (POETIC), and a founding institution of the Pediatric Brain Tumor Consortium. We are also members of the Pediatric Blood and Marrow Transplant Consortium (PBMTC).
  • skilled at improving current therapeutic approaches and outcomes of hard to treat pediatric brain tumors.

Rapidly translating scientific discoveries to the bedside is a major focus of the program. Members of our brain tumor team:

  • played a key role in the identification and application of anti-angiogenic treatments for pediatric brain tumors
  • launched new studies investigating gene profiling of patients’ tumors and the development of personalized treatment approaches
  • pioneered the development of new treatments for specific highly malignant tumors such as ATRT are developing tissue registries to better classify and treat certain types of brain tumors

General Information About Childhood Brain and Spinal Cord Tumors

Dramatic improvements in survival have been achieved for children and adolescents with cancer. Between 1975 and 2002, childhood cancer mortality decreased by more than 50%.[1] Childhood and adolescent cancer survivors require close follow-up because cancer therapy side effects may persist or develop months or years after treatment. Refer to the PDQ summary on Late Effects of Treatment for Childhood Cancer for specific information about the incidence, type, and monitoring of late effects in childhood and adolescent cancer survivors.

Primary brain tumors are a diverse group of diseases that together constitute the most common solid tumor of childhood. Brain tumors are classified according to histology, but tumor location and extent of spread are also important factors that affect treatment and prognosis. Immunohistochemical analysis, cytogenetic and molecular genetic findings, and measures of proliferative activity are increasingly used in tumor diagnosis and classification.

Incidence

Primary central nervous system tumors are a diverse group of diseases that together constitute the most common solid tumor in childhood. Between 2,500 and 3,500 children are diagnosed in the United States each year.

References:

  1. Smith MA, Seibel NL, Altekruse SF, et al.: Outcomes for children and adolescents with cancer: challenges for the twenty-first century. J Clin Oncol 28 (15): 2625-34, 2010.

Classification of Central Nervous System Tumors

The classification of childhood central nervous system (CNS) tumors is based on histology and location.[1] Tumors are classically categorized as infratentorial, supratentorial, parasellar, or spinal. Immunohistochemical analysis, cytogenetic and molecular genetic findings, and measures of proliferative activity are increasingly used in tumor diagnosis and classification and will likely affect classification and nomenclature in the future.

Primary CNS spinal cord tumors comprise approximately 1% to 2% of all childhood CNS tumors. The classification of spinal cord tumors is based on histopathologic characteristics of the tumor and does not differ from that of primary brain tumors.[1]

Infratentorial (posterior fossa) tumors include the following:

  1. Cerebellar astrocytomas (most commonly pilocytic, but also fibrillary and less frequently, high grade).
  2. Medulloblastomas (including classic, desmoplastic/nodular, extensive nodularity, anaplastic, or large cell variants).
  3. Ependymomas (cellular, papillary, clear cell, tanycytic, or anaplastic).
  4. Brain stem gliomas (typically diffuse intrinsic pontine gliomas and focal, tectal, and exophytic cervicomedullary gliomas are most frequently pilocytic astrocytomas).
  5. Atypical teratoid/rhabdoid tumors.
  6. Choroid plexus tumors (papillomas and carcinomas).
  7. Rosette-forming glioneuronal tumors of the fourth ventricle.

Supratentorial tumors include the following:

  1. Low-grade cerebral hemispheric astrocytomas (grade I [pilocytic] astrocytomas or grade II [diffuse] astrocytomas).
  2. High-grade or malignant astrocytomas (anaplastic astrocytomas and glioblastoma [grade III or grade IV]).
  3. Mixed gliomas (low- or high-grade).
  4. Oligodendrogliomas (low- or high-grade).
  5. Primitive neuroectodermal tumors (PNETs) (cerebral neuroblastomas, pineoblastomas, and ependymoblastomas).
  6. Atypical teratoid/rhabdoid tumors.
  7. Ependymomas (cellular or anaplastic).
  8. Meningiomas (grades I, II, and III).
  9. Choroid plexus tumors (papillomas and carcinomas).
  10. Tumors of the pineal region (pineocytomas, pineoblastomas, pineal parenchymal tumors of intermediate differentiation, and papillary tumors of the pineal region), and germ cell tumors.
  11. Neuronal and mixed neuronal glial tumors (gangliogliomas, desmoplastic infantile astrocytoma/gangliogliomas, dysembryoplastic neuroepithelial tumors, and papillary glioneuronal tumors).
  12. Other low-grade gliomas (including subependymal giant cell tumors and pleomorphic xanthoastrocytoma).
  13. Metastasis (rare) from extraneural malignancies.

Parasellar tumors include the following:

  1. Craniopharyngiomas.
  2. Diencephalic astrocytomas (central tumors involving the chiasm, hypothalamus, and/or thalamus) that are generally low-grade (including astrocytomas, grade I [pilocytic] or grade II [diffuse]).
  3. Germ cell tumors (germinomas or nongerminomatous).

Spinal cord tumors include the following:

  1. Low-grade cerebral hemispheric astrocytomas (grade I [pilocytic] astrocytomas or grade II [diffuse] astrocytomas).
  2. High-grade or malignant astrocytomas (anaplastic astrocytomas and glioblastoma [grade III or grade IV]).
  3. Gangliogliomas.
  4. Ependymomas (often myxopapillary).

References:

  1. Louis DN, Ohgaki H, Wiestler OD, et al., eds.: WHO Classification of Tumours of the Central Nervous System. 4th ed. Lyon, France: IARC Press, 2007.

General Approach to Care for Children with Brain and Spinal Cord Tumors

Important concepts that should be understood by those treating and caring for a child who has a brain tumor or spinal cord tumor include the following:

  1. The cause of most childhood brain tumors remains unknown.[1]
  2. Selection of an appropriate therapy can only occur if the correct diagnosis is made and the stage of the disease is accurately determined.
  3. Children with primary brain or spinal cord tumors represent a major therapy challenge that, for optimal results, requires the coordinated efforts of pediatric specialists in fields such as neurosurgery, neuropathology, radiation oncology, pediatric oncology, neuro-oncology, neurology, rehabilitation, neuroradiology, endocrinology, and psychology, who have special expertise in the care of patients with these diseases.[2][3] For example, radiation therapy of pediatric brain tumors is technically demanding and should be performed in centers that have experience in this area.
  4. For most childhood brain and spinal cord tumors, the optimal treatment regimen has not been determined. Children who have brain and spinal cord tumors should be considered for enrollment in a clinical trial when an appropriate study is available. Such clinical trials are being carried out by institutions and cooperative groups. Survival of childhood cancer has advanced as a result of clinical trials that have attempted to improve upon the best accepted therapy available. Clinical trials in pediatrics are designed to compare new therapy with therapy that is currently accepted as standard. This comparison may be done in a randomized study of two treatment arms or by evaluating a single new treatment and then comparing the results with those previously obtained from existing therapy. Information about ongoing clinical trials is available from the NCI Web site.
  5. While more than 70% of children diagnosed with brain tumors will survive for more than 5 years after diagnosis, survival rates are wide-ranging depending on tumor type and stage. Long-term sequelae related to the initial presence of the tumor and subsequent treatment are common.[4][5][6] Debilitating effects on growth and neurologic development have frequently been observed after radiation therapy, especially in younger children.[7][8][9] Secondary tumors have increasingly been diagnosed in long-term survivors.[10] For this reason, the role of chemotherapy in allowing a delay or reduction in the administration of radiation therapy is under study, and preliminary results suggest that chemotherapy can be used to delay, limit, and sometimes obviate, the need for radiation therapy in children with benign and malignant lesions.[11][12][13] Long-term management of these patients is complex and requires a multidisciplinary approach.

    (Refer to the PDQ summary on Late Effects of Treatment for Childhood Cancer for more information about possible long-term or late effects.)

  6. Guidelines for pediatric cancer centers and their role in the treatment of pediatric patients with cancer have been outlined by the American Academy of Pediatrics.[14]

References:

  1. Fisher JL, Schwartzbaum JA, Wrensch M, et al.: Epidemiology of brain tumors. Neurol Clin 25 (4): 867-90, vii, 2007.

  2. Blaney SM, Haas-Kogan D, Young Poussaint T, et al.: Gliomas, ependymomas, and other nonembryonal tumors of the central nervous system. In: Pizzo PA, Poplack DG, eds.: Principles and Practice of Pediatric Oncology. 6th ed. Philadelphia, Pa: Lippincott Williams and Wilkins, 2011, pp 717-771.

  3. Pollack IF: Brain tumors in children. N Engl J Med 331 (22): 1500-7, 1994.

  4. Smith MA, Seibel NL, Altekruse SF, et al.: Outcomes for children and adolescents with cancer: challenges for the twenty-first century. J Clin Oncol 28 (15): 2625-34, 2010.

  5. Reimers TS, Mortensen EL, Nysom K, et al.: Health-related quality of life in long-term survivors of childhood brain tumors. Pediatr Blood Cancer 53 (6): 1086-91, 2009.

  6. Iuvone L, Peruzzi L, Colosimo C, et al.: Pretreatment neuropsychological deficits in children with brain tumors. Neuro Oncol 13 (5): 517-24, 2011.

  7. Ris MD, Packer R, Goldwein J, et al.: Intellectual outcome after reduced-dose radiation therapy plus adjuvant chemotherapy for medulloblastoma: a Children's Cancer Group study. J Clin Oncol 19 (15): 3470-6, 2001.

  8. Johnson DL, McCabe MA, Nicholson HS, et al.: Quality of long-term survival in young children with medulloblastoma. J Neurosurg 80 (6): 1004-10, 1994.

  9. Packer RJ, Sutton LN, Goldwein JW, et al.: Improved survival with the use of adjuvant chemotherapy in the treatment of medulloblastoma. J Neurosurg 74 (3): 433-40, 1991.

  10. Jenkin D: Long-term survival of children with brain tumors. Oncology (Huntingt) 10 (5): 715-9; discussion 720, 722, 728, 1996.

  11. Duffner PK, Horowitz ME, Krischer JP, et al.: Postoperative chemotherapy and delayed radiation in children less than three years of age with malignant brain tumors. N Engl J Med 328 (24): 1725-31, 1993.

  12. Packer RJ, Lange B, Ater J, et al.: Carboplatin and vincristine for recurrent and newly diagnosed low-grade gliomas of childhood. J Clin Oncol 11 (5): 850-6, 1993.

  13. Mason WP, Grovas A, Halpern S, et al.: Intensive chemotherapy and bone marrow rescue for young children with newly diagnosed malignant brain tumors. J Clin Oncol 16 (1): 210-21, 1998.

  14. Guidelines for the pediatric cancer center and role of such centers in diagnosis and treatment. American Academy of Pediatrics Section Statement Section on Hematology/Oncology. Pediatrics 99 (1): 139-41, 1997.

Stage Information and Treatment of Newly Diagnosed and Recurrent Childhood Brain Tumors

Presently, there is no uniformly accepted staging system for most childhood brain tumors. These tumors are classified and treated based on their histology and location within the brain (see Table below). However, with advances in molecular data, it is conceivable that genomic factors will refine classification approaches for certain groups of tumors, such as medulloblastomas [1][2] and low-grade gliomas.[3][4]

Newly Diagnosed or Recurrent Tumor Type and Its Related PDQ Treatment Summary

Tumor Type

Pathologic Subtype

Related PDQ Treatment Summary

Astrocytomas and Other Tumors of Glial Origin

Low-Grade Astrocytomas

Diffuse fibrillary astrocytoma

Childhood Astrocytomas Treatment

Gemistocytic astrocytoma

Oligoastrocytoma

Oligodendroglioma

Pilocytic astrocytoma

Pilomyxoid astrocytoma

Pleomorphic xanthoastrocytoma

Protoplasmic astrocytoma

Subependymal giant cell astrocytoma

High-Grade Astrocytomas

Anaplastic astrocytoma

Childhood Astrocytomas Treatment

Anaplastic oligoastrocytoma

Anaplastic oligodendroglioma

Giant cell glioblastoma

Glioblastoma

Gliomatosis cerebri

Gliosarcoma

Brain Stem Glioma

Diffuse intrinsic pontine glioma

Childhood Brain Stem Glioma Treatment

Focal or low-grade brain stem glioma

CNS Embryonal Tumors

Medulloblastomas

Anaplastic

Childhood CNS Embryonal Tumors Treatment

Classic

Desmoplastic/nodular

Large cell

Medulloblastoma with extensive nodularity

CNS Primitive Neuroectodermal Tumors (PNETs)

CNS ganglioneuroblastoma

CNS neuroblastoma

Ependymoblastoma

Medulloepithelioma

Pineal Parenchymal Tumors

Pineoblastoma

CNS Atypical Teratoid/Rhabdoid Tumor

Childhood CNS Atypical Teratoid/Rhabdoid Tumor Treatment

CNS Germ Cell Tumors

Germinomas

Childhood CNS Germ Cell Tumors Treatment

Teratomas

Immature teratoma

Mature teratoma

Teratoma with malignant transformation

Non-Germinomatous Germ Cell Tumors

Choriocarcinoma

Embryonal carcinoma

Mixed germ cell tumor

Yolk sac tumor

Craniopharyngioma

Childhood Craniopharyngioma Treatment

Ependymoma

Subependymoma (WHO Grade I)

Childhood Ependymoma Treatment

Myxopapillary ependymoma (WHO Grade I)

Ependymoma (WHO Grade II)

Anaplastic ependymoma (WHO Grade III)

Tumors of the Choroid Plexus

CNS = central nervous system; WHO = World Health Organization.

Recurrence is not uncommon in both low-grade and malignant childhood brain tumors and may occur many years after initial treatment. Disease may occur at the primary tumor site or, especially in malignant tumors, at noncontiguous central nervous system (CNS) sites. Systemic relapse is rare but may occur. At time of recurrence, a complete evaluation for extent of relapse is indicated for all malignant tumors and, at times, for lower-grade lesions. Biopsy or surgical re-resection may be necessary for confirmation of relapse; other entities, such as secondary tumor and treatment-related brain necrosis, may be clinically indistinguishable from tumor recurrence. The determination of the need for surgical intervention must be individualized based on the initial tumor type, the length of time between initial treatment and the reappearance of the lesion, and the clinical picture.

Early-phase therapeutic trials may be available for selected patients via Children's Oncology Group phase I institutions, the Pediatric Brain Tumor Consortium, or other entities.

References:

  1. Northcott PA, Shih DJ, Peacock J, et al.: Subgroup-specific structural variation across 1,000 medulloblastoma genomes. Nature 488 (7409): 49-56, 2012.

  2. Kool M, Korshunov A, Remke M, et al.: Molecular subgroups of medulloblastoma: an international meta-analysis of transcriptome, genetic aberrations, and clinical data of WNT, SHH, Group 3, and Group 4 medulloblastomas. Acta Neuropathol 123 (4): 473-84, 2012.

  3. Jones DT, Kocialkowski S, Liu L, et al.: Tandem duplication producing a novel oncogenic BRAF fusion gene defines the majority of pilocytic astrocytomas. Cancer Res 68 (21): 8673-7, 2008.

  4. Pfister S, Janzarik WG, Remke M, et al.: BRAF gene duplication constitutes a mechanism of MAPK pathway activation in low-grade astrocytomas. J Clin Invest 118 (5): 1739-49, 2008.

Stage Information and Treatment of Newly Diagnosed and Recurrent Childhood Spinal Cord Tumors

There is no uniformly accepted staging system for childhood primary spinal cord tumors. These tumors are classified and treated based on their location within the spinal cord and histology. Refer to the following PDQ summaries for more information on the staging and treatment of newly diagnosed and recurrent childhood spinal cord tumors:

  • Childhood Astrocytomas Treatment.
  • Childhood Central Nervous System Embryonal Tumors Treatment.
  • Childhood Ependymoma Treatment.

This information is provided by the National Cancer Institute.

This information was last updated on January 28, 2014.

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