Ependymomas are derived from the ependymal cells lining the ventricular system; they occur throughout the CNS. They are seen infrequently in children.1
In children, 90% of ependymomas are intracranial neoplasms; 60% to 70% arise in the posterior fossa, primarily within the fourth ventricle.
Etiology:
Rachel
The cause of ependmomas is unknown. Research is being carried out into possible causes.2
Signs & Symptoms:
Brandon Ependymomas signs and symptoms can vary from child to child depending on the size and location of the tumor.8 These include:3
Headaches (especially upon wakening)
Nausea and vomiting (especially upon wakening)
Lethargy and irritability
Problems eating or walking
Enlarged head size or fontanelles (the soft spot in the skull bones before the head is fused). This usually only applies to infants.
Diagnostic Procedures:
Brandon The diagnostic procedures for ependymomas are the same as many other Central Nervous System (CNS) abnormailites. These tests include:3
Physical Examination
Magnetic Resonance Imaging (MRI) scan
Computed Tomography (CT) scan
Biopsy- if a tumor is located to determine type and grade
Lumbar puncture (spinal tap)- this is useful in determining if any tumor cells have spread distally to the cerebrospinal fluid (CSF).
Histology:
Ashley Ependymoma tumors are tumors that arise directly from the ependymal cells located in the ventricular system. 4 Most of these tumors in children are indicated as intracranial neoplasms. 4 The image below demonstrates ependymal cells in a 32 week old fetus. 5 To help further delineate, these cells are located in a horizontal row with cilia extending into the ventricle.
Figure 1. Reprinted from Introduction to Pathobiology of the Nervous System. 5
This image indicates a sample with ependymoma cells. The markers indicate the perivascular rosettes that characterize this cancer. 5
Figure 2. Reprinted from Introduction to Pathobiology of the Nervous System. 5
Lymph node drainage:
Ashley Because the brain doesn't contain lymph node channels, metastasis do not occur through lymphatics.4
Metastatic spread:
Amanuel Ependymomas rarely metastasis outside central nervous system. Most recurrences occur locally near the original tumor location. Extraneural metastasis mainly occurs in distant bone, lung, liver, and lymph nodes.6
Grading:
Amanuel World health organization's (WHO) classification for staging ependymal tumors is as follows:7
Grade I - Subepyndemoma
Grade I - Myxopapillary Ependymoma
Grade II - Ependymoma [variants include cellular, papillary, tanycytic, clear cell, and mixed]
Grade III - Anaplastic (malignant) Ependymoma
Staging:
Lindsey There is no standard staging system for childhood ependymoma.8 Instead, the plan for cancer treatment after surgery depends on the following: -Whether any cancer cells remain after surgery. -Whether the cancer has spread to other parts of the brain or spinal cord. -The age of the child
Radiation side effects:
Lindsey -Growth disturbances are common; growth hormone deficiency in most long term survivors9-adverse effects may be directly related to the biologically effective dose -Gradual onset of endocrine deficits (ex: growth hormone, thyroid-stimulating hormone, adrenocorticotropic hormone) -Late optic neuropathy or brain necrosis in < 10% of cases of patients treated to doses > 60Gy -Secondary malignant neoplasms -Hyperfractionated treatments are associated with moderate acute epithelial toxicity such as otitis and radioepidermitis -Late toxicities with high dose hyperfractionated treatments: neurocognitive deficits, hearing loss, leukoencephalopathy, diffuse microhemorrhages, dystrophic calcifications on MRI
Prognosis:
Kevin Overall survival is approximately 55%. Age and extent of tumor resection are major prognostic factors.
5 year survival rate: Infants < 1 year: 25% Children 1-4 yrs: 46% Children > 5 yrs: > 70% For patients with a complete tumor resection, survival rates are 60-80% following radiation treatment have been reported. For patient's with a partial tumor resection, survival rates drop to less than 30%.10
Treatments:
Kevin General Management
Maximal surgical resection is the optimal intial therapy, although it possibly should be delayed in infants in whom response to initial chemotherapy may permit more complete "secondary" resection.
For supratentorial tumors, size and location may limit resectability.
Radiation therapy adds to disease control and survival. Two retrospective studies found the survival to be 0% and 13% with surgery alone compared with 45% and 59% with radiation.
Ependymomas are relatively sensitive to chemotherapy, especially alkylating agents and platinum compounds.
Radiation Therapy
Debate continues regarding the appropriate irradiation volume for intracranial ependymomas.
Disease contral rates in contemporary series show no advantage to full cranial or craniospinal volumes compared with wide local fields, based on modern imaging.
The standard local volume for posterior fossa ependymomas encompasses the entire posterior fossa, the inferior border is typically at the C2-3 interface.
For tumors extending into the upper cervical spine, the inferior margin should be two vertebral levels below the preoperative tumor extent until field reduction at 45 Gy.
Based on the recognized failure pattern at sites of identified invasion or residual disease, there now is greater acceptance of more localized treatment volumes.
For supratentorial ependymomas, wide local fields are defined by preoperative tumor extent, accounting for shifts in the normal brain postoperatively; margins of 2 to 3 cm are recommended.
For intraventricular extension, full ventricular irradiation (45 Gy) is appropriate.
Current guidelines call for 50 to 55 Gy to the primary tumor site, including field reduction at 45 Gy to more narrowly encompass the tumor bed.
Boost doses to 55-65 Gy have been recommended and are directed to small volumes of known residual disease, preferably using stereotactic radiosurgery or fractionated stereotactic irradiation.11
Treatment planning images showing the isodose distribution of 6 field IMRT plan to posterior fossa.12
TD 5/5:
Jenn Tissue dose associated with 5% injury rate within 5 years. (TD 5/5)13
Ear (Middle): Serous otitis 5000cGy
Ear (Vestibular): Meniere’s syndrome 6000cGy
Retina: Blindness 5500cGy
Cornea: Blindness 5000cGy
Lens: Blindness 500cGy
Salivary Glands: Xerostomia 5000cGy
Oral cavity and pharynx: Ulceration 6000cGy
Pituitary: Reduced hormone production 4500cGy
Brainstem: Necrosis, infarction 5000cGy
References:
Chao KS, Perez CA, Brady LW. Radiation Oncology Management Decisions. 3rd ed. Philadelphia, PA: Lippincott, Williams, and Wilkins; 2011: 724.
Ependymomas signs and symptoms can vary from child to child depending on the size and location of the tumor.8 These include:3
The diagnostic procedures for ependymomas are the same as many other Central Nervous System (CNS) abnormailites. These tests include:3
Ependymoma tumors are tumors that arise directly from the ependymal cells located in the ventricular system. 4 Most of these tumors in children are indicated as intracranial neoplasms. 4 The image below demonstrates ependymal cells in a 32 week old fetus. 5 To help further delineate, these cells are located in a horizontal row with cilia extending into the ventricle.
Because the brain doesn't contain lymph node channels, metastasis do not occur through lymphatics.4
Ependymomas rarely metastasis outside central nervous system. Most recurrences occur locally near the original tumor location.
Extraneural metastasis mainly occurs in distant bone, lung, liver, and lymph nodes.6
World health organization's (WHO) classification for staging ependymal tumors is as follows:7
There is no standard staging system for childhood ependymoma.8 Instead, the plan for cancer treatment after surgery depends on the following:
-Whether any cancer cells remain after surgery.
-Whether the cancer has spread to other parts of the brain or spinal cord.
-The age of the child
-Growth disturbances are common; growth hormone deficiency in most long term survivors9-adverse effects may be directly related to the biologically effective dose
-Gradual onset of endocrine deficits (ex: growth hormone, thyroid-stimulating hormone, adrenocorticotropic hormone)
-Late optic neuropathy or brain necrosis in < 10% of cases of patients treated to doses > 60Gy
-Secondary malignant neoplasms
-Hyperfractionated treatments are associated with moderate acute epithelial toxicity such as otitis and radioepidermitis
-Late toxicities with high dose hyperfractionated treatments: neurocognitive deficits, hearing loss, leukoencephalopathy, diffuse microhemorrhages, dystrophic calcifications on MRI
Overall survival is approximately 55%.
Age and extent of tumor resection are major prognostic factors.
5 year survival rate: Infants < 1 year: 25%
Children 1-4 yrs: 46%
Children > 5 yrs: > 70%
For patients with a complete tumor resection, survival rates are 60-80% following radiation treatment have been reported. For patient's with a partial tumor resection, survival rates drop to less than 30%.10
General Management
Radiation Therapy
Treatment planning images showing the isodose distribution of 6 field IMRT plan to posterior fossa.12
Tissue dose associated with 5% injury rate within 5 years. (TD 5/5)13
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