Pathology of Ependymoma; Histopathological Features, Cell morphology, Immunohistochemistry скачать в хорошем качестве

Pathology of Ependymoma; Histopathological Features, Cell morphology, Immunohistochemistry

Ependymoma is a glial tumor that arises from ependymal cells, which line the ventricles of the brain and the central canal of the spinal cord. It’s a diverse tumor with distinct histological and molecular features depending on its location and subtype. 🧠 Key Pathological Features Perivascular pseudorosettes: Tumor cells arranged around blood vessels with nuclei pushed outward, forming a halo of cytoplasmic processes. Ependymal rosettes: True rosettes with a central lumen, mimicking the normal ependymal canal. GFAP and S100 positivity: These glial markers are typically expressed in ependymoma cells. Dot-like EMA reactivity: Seen in the perinuclear region, helpful in diagnosis. Olig2 negativity: Helps distinguish ependymomas from other gliomas. 🧬 Molecular Classification (WHO 2021) Ependymomas are now classified by location and genetic profile: Location Subtypes (Examples) Supratentorial ZFTA fusion-positive, YAP1 fusion-positive Posterior fossa Group A (PFA), Group B (PFB) Spinal cord Classic, MYCN-amplified, Myxopapillary Each subtype has unique behavior and prognosis. For instance, PFA tumors are more aggressive and common in children, while spinal ependymomas are more frequent in adults2. 🔬 Histological Variants Classic cellular: Uniform cells with round nuclei and pseudorosettes. Tanycytic: Elongated cells with less obvious rosettes. Myxopapillary: Found in the filum terminale, with papillary architecture and mucinous stroma. Anaplastic (Grade 3): High mitotic activity, necrosis, and microvascular proliferation3. 🧠 Gross & Microscopic Appearance Gross: Soft, gray, well-circumscribed masses often found in the fourth ventricle or spinal cord. Microscopy: Tadpole-like cells, hyalinized vessels, calcifications, and monotonous nuclear features. 🧪 Cytogenetics Loss of 22q: Common in both spinal and intracranial tumors. Gain of 1q: Seen in intracranial types. MYCN amplification: Associated with aggressive spinal variants. #Pathology #Ependymoma