1. The answer is c.
Recall that there is a bimodal age distribution of ependymomas. The first peak is for children under five years old and the second for adults between the ages of 20-40 years. There is also slight female predominance, with 64% of all intracranial brain tumours presenting in females.
Frequency of Ependymomas and Tumour Features
| Proportion of Pediatric Neoplasms |
8-10% |
| Median Age, all ependymomas |
22 years |
| Median Age, pediatric ependymomas |
3-4 years |
| Pediatric Patients < 5 years |
60% |
| Pediatric Patients > 15 years |
4% |
| Racial Bias |
None |
| Gender Bias |
3:2 (female predominance) |
For more information read the section on incidence.
2. The answer is b.
Infratentorial ependymomas are more common than supratentorial ependymomas in children. Anatomically the lateral ventricles, third ventricles and frontal lobe are supratentorial locations.
For more information review the location section.
3. The answer is a and c.
Supratentorial ependymomas are less common in children. They arise from ependymal cells lining the ventricles. They have a predilection for frontal, temporal, and parietal lobes, as well as for the third ventricle.
For more information review the location section.
4. The answers are a, b, c, f.
Recall that ependymomas are characterized by perivascular pseudorosettes and true ependymal rosettes. In general, tumour cells are polygonal with large nuclei. Glial fibrillary acidic protein (GFAP) expression is common in ependymal tumour cells. Macroscopically these tumours are characterized by calcifications.
For more information review the pathology section:
Table. Summary of Histological Features of Ependymomas
5. The answer is a.
Tumours in the posterior fossa can lead to increased intracranial pressure and meningismus. Children may present with vomiting (worse in the morning) and neck stiffness. Nystagmus is secondary to cranial nerve compression. Children with ependymomas often have a long history of symptoms.
For more information review the section on clinical presentation.
6. The answer is b and e.
Subarachnoid seeding and high grade pathology are associated with worse outcomes in patients.
Recall that several factors are associated with the prognosis of pediatric patients. Surgical resection is considered the most important of these. Many new studies indicate gross total resection does improve both overall and progression-free survival.
For more information review the section on prognosis.
7. The answer is a.
Localized disease should be treated with localized radiation therapy. Craniospinal radiation therapy is no longer given for localized disease.
Fusion of a pre-op MRI with a planning CT can help to define the tumour bed. Relatively tight margins on the tumour bed may be used as these tumours rarely invade adjacent brain. The GTV should include the entire tumour bed based on preoperative imaging, anatomical changes postoperatively and possible areas of microscopic residual disease. The CTV is defined by a 1 and 1.5cm margin on the GTV. Depending on the immobilization technique, the PTV is expanded by an additional 5-7mm.
Most data indicate that there is improved disease with greater than >45 Gy therefore doses of 50-55 GY (1.8 Gy per day) are usually used for local control.
For more information review the treatment section.
8. The answer is b.
Most data indicate that there is improved disease with greater than >45 Gy therefore doses of 50-55 GY (1.8 Gy per day) are usually used for local control.
For more information review the treatment section.