Ependymoma overview

# Overview
Ependymoma is the third most common neuroepithelial tumor of the central nervous system (CNS) in childhood. It arises for ependymal cells of the central nervous system and is dominated by intracranial mass. The World Health Organization (WHO) classification of CNS tumors defines several histopathological variants of ependymoma (grade I, II, III). On gross pathology, a well-encapsulated tumor arises from the floor of the fourth ventricle, situated in the lower back portion of the brain is a characteristic finding of ependymoma. On microscopic histopathological analysis, perivascular pseudorosettes are characteristic findings of ependymoma. Development of ependymoma is the result of multiple genetic mutations (ERBB2, ERBB4, MMP2, MMP14, NOTCH1, and MEN1). There are no established causes for ependymomas. Ependymoma must be differentiated from medulloblastoma, choroid plexus papilloma, and glioblastoma. Common risk factors in the development of ependymoma are children with certain hereditary diseases (neurofibromatosis type II and Turcot syndrome),  ERBB2, ERBB4, and human telomerase reverse transcriptase TERT gene expression, over-expression of kinetochore proteins, and down-regulation of metallothioneins.Symptoms of ependymoma include headache, nausea, vomiting, blurry or double vision, drowsiness (after several hours of the above symptoms), irritability, ataxia, neck pain, cranial nerve palsies, seizures, focal neurologic deficits, back pain, lower extremity weakness, bowel and bladder dysfunction. MRI may be diagnostic of ependymoma. Finding on brain MRI suggestive of ependymoma include large mixed cystic/solid lesion with haemorrhage and fluid which may indicate areas of necrosis. The predominant therapy for ependymoma is surgical resection. Adjunctive chemoradiation may be required.

# Classification
Ependymoma may be classified into several subtypes based on WHO classification (grade I, II, III) and the site of origin.

# Pathology
On gross pathology, a well-encapsulated tumor arises from the floor of the fourth ventricle, situated in the lower back portion of the brain is a characteristic finding of ependymoma. On microscopic histopathological analysis, perivascular pseudorosettes are characteristic findings of ependymoma. Development of ependymoma is the result of multiple genetic mutations (ERBB2, ERBB4, MMP2, MMP14, NOTCH1, and MEN1).

# Causes
There are no established causes for ependymomas.

# Epidemiology and Demographics
The incidence of ependymoma is approximately 0.05 to 0.08 per 100,000 individuals in the United States.The posterior fossa tumours tend to present more commonly in the paediatric age group (mean age at diagnosis is 6 years of age). Men and women are affected equally by ependymomal tumors.

# Risk Factors
Common risk factors in the development of ependymoma are children with certain hereditary diseases (neurofibromatosis type II and Turcot syndrome), over-expression of kinetochore proteins, and down-regulation of metallothioneins.

# Differentiating Ependymoma from other Diseases
Ependymoma must be differentiated from medulloblastoma, choroid plexus papilloma, and glioblastoma.

# Natural History, Complication and Prognosis
If left untreated, patients with ependymoma may progress to develop nausea, vomiting, headache, and irritability. Common complications of ependymoma include seizure, hydrocephalus, muscle paralysis, and speech problems.

# Diagnosis

## History and Symptoms
Symptoms of ependymoma include headache, nausea, and irritability.

## Physical Examination
Patients with ependymoma usually appear well. Physical examination of patients with ependymoma is usually remarkable for altered mental status, spasticity, and muscle weakness.

## Staging
There is no established system for the staging of ependymoma.

## Laboratory Findings
There are no diagnostic lab findings associated with ependymoma.

## CT
Head CT scan may be diagnostic of ependymoma. Findings on CT scan suggestive of ependymoma include heterogeneous mass with coarse calcification, solid component, and cystic component.

## MRI
Brain MRI may be diagnostic of ependymoma. Finding on brain MRI suggestive of ependymoma include large mixed cystic/solid lesion with haemorrhage and fluid which may indicate areas of necrosis.

## Ultrasound
Intraoperative ultrasound is used in intradural spinal ependymomas.

## Other Diagnostic Studies
Other diagnostic studies for ependymoma include EEG, which demonstrates various abnormalities, and cerebrospinal fluid analysis, which demonstrates positive cytology.

# Treatment

## Medical Therapy
The predominant therapy for ependymoma is surgical resection. Adjunctive chemoradiation may be required.

## Surgery
Surgery is the main stay of treatment for myxopapillary ependymoma (WHO grade 1), subependymoma (WHO grade 1), ependymoma (WHO grade I), and anaplastic ependymoma (WHO grade III).

## Primary Prevention
There are no primary preventive measures available for ependymoma.

## Secondary Prevention
Secondary prevention strategies following ependymoma include regular clinical assessment and neuroimaging.