Ependymoma
Ependymomas are usually slow-growing tumors of the central nervous system that have morphological similarities to the cerebral ventricles and the spinal canal lining ependymal cells. Two-thirds of ependymomas infratentorial sit on the 4th ventricle, the remaining third supratentorial and mostly in the periventricular white matter. Although she prefers to occur in children and young adults, ependymomas may occur at any age.
Symptoms
Due to its location near the ventricle ependymomas often impede the flow of cerebrospinal fluid, which can lead to an increase in intracranial pressure. This results in persistent headache, nausea and vomiting, and hydrocephalus may develop.
Diagnosis
In MRI images of the head, the ependymoma typically provides is as circumscribed lesion with respect to the ventricular system, which has a heterogeneous signal pattern with cystic shares as well as moderately and garland- like accumulates a contrast agent. In 50% calcifications can be seen in the sectional imaging. Cytological examination of the cerebrospinal fluid and tumor biopsy may contribute to the diagnosis.
Pathology
Ependymomas are assigned to the grade II according to the WHO classification of tumors of the central nervous system, anaplastic ependymomas the grade III. The particular related Ependymoblastoma belongs contrast to the group of primitive neuroectodermal tumors ( PNET ) that are not related to the histogenetically ependymomas. A special form is the predominantly spinal (in the region of the filum terminale ) localized so-called myxopapillary ependymoma, which usually has a favorable prognosis ( WHO grade I).
Intraoperatively ependymomas represent mostly as well-defined, whitish mass dar. Histologically, is to glial tumors with ependymal differentiation, that is, the tumor cells tend to like the ependymal cells to form surfaces. Diagnosis are called ependymal rosettes, in which several tumor cells form a central lumen. Are also typical perivascular pseudo- rosettes in which to align the bearing tumor cells around blood vessels fine fibrillar appendages on this way. As glial tumors express ependymomas ( especially in the perivascular pseudo- rosettes ) glial fibrillary acidic protein (GFAP). In the immunohistochemical staining for epithelial membrane antigen (EMA ) can be proven beyond often intracytoplasmic Mikrolumina.
In individual cases, ependymomas may also have unusual histological features such as giant cells, cysts or islands with neuronal differentiation.
Therapy
The location directly at the brainstem difficult surgery immensely; However, it is the most effective therapy. The importance of radiotherapy in completely removed ependymomas is unclear, however, it seems certain that patients in whom a complete resection could not be achieved, may benefit from radiation therapy. Outside controlled clinical trials of adjuvant chemotherapy usually is of no fundamental importance. However, may be delayed in young children with chemotherapy, have many side effects in this age group radiotherapy. Recent data support this assumption. Especially in children therapy in clinical trials should be sought.
Forecast
Since ependymomas are often only incompletely resected due to their location, the extent of resection of particular importance for the prognosis. The neuropathological classification, which also includes a central neuropathological assessment center, however, is not classified as prognostically relevant in the study of Robertson et al. Other studies came to opposite conclusions with prognostically unfavorable importance of cell density ( cellularity ), Mitosendichte ( Mitosenanzahl per high power field ), endothelial profiles ration and degree of differentiation. However, depending on the carried out investigation and study, the histological prognostic factors may vary. In addition to the histology or neuropathological classification, the age obviously plays a prognostic role. Children aged less than 3 years tend to have a poorer prognosis.