What are Ependymomas?
Ependymomas are a type of
glial tumor that arise from ependymal cells lining the ventricles of the brain and the central canal of the spinal cord. These tumors are part of a broader category known as gliomas, which originate from
glial cells, the supportive cells in the central nervous system (CNS).
Histological Features
Histologically, ependymomas are characterized by their unique cellular architecture. The cells often form
pseudo-rosettes and true rosettes. In pseudo-rosettes, tumor cells are arranged around blood vessels, whereas in true rosettes, tumor cells form a radial pattern around an empty lumen. The cytoplasm of ependymal cells is eosinophilic, and their nuclei are round to oval with sparse chromatin.
Subtypes of Ependymomas
There are several subtypes of ependymomas, including
myxopapillary ependymoma,
subependymoma, and anaplastic ependymoma. Myxopapillary ependymomas are generally found in the spinal cord and have a benign course. In contrast, anaplastic ependymomas are more aggressive and are marked by increased cellularity and mitotic activity.
Diagnosis
The diagnosis of ependymomas involves a combination of imaging techniques like
MRI and histopathological examination. During histological examination, immunohistochemistry is used to identify specific markers such as
GFAP (Glial Fibrillary Acidic Protein) and
EMA (Epithelial Membrane Antigen) which are commonly expressed in ependymomas.
Grading and Prognosis
Ependymomas are graded based on the
WHO classification of CNS tumors. The grades range from Grade I (least aggressive) to Grade III (most aggressive). The prognosis of ependymomas varies significantly based on the grade and location of the tumor. Generally, lower-grade ependymomas have a better prognosis compared to higher-grade ones.
Treatment Options
Treatment of ependymomas typically involves a combination of surgical resection and radiotherapy. Complete surgical removal is the goal, but the feasibility depends on the tumor's location and involvement with critical structures. For higher-grade tumors, adjuvant therapies such as radiation and chemotherapy may be considered.Research and Future Directions
Ongoing research is focused on understanding the genetic and molecular underpinnings of ependymomas to develop targeted therapies. Advances in
molecular profiling and
gene expression studies are paving the way for personalized treatment approaches, which could significantly improve outcomes for patients with these tumors.
