astrocytoma

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Related to Pilocytic astrocytoma: medulloblastoma

astrocytoma

[‚as·trə‚sī′tōm·ə]
(medicine)
A slow-growing glial tumor made up of cells resembling astrocytes; often it will undergo malignant change and assume the appearance and growth characteristics of a glioblastoma.
References in periodicals archive ?
2) Holocord involvement typically occurs with pilocytic astrocytomas (Figure 2).
NF1 is among the most common tumor predisposition syndromes, but it accounts for only about 15 percent of pediatric low-grade gliomas known as pilocytic astrocytomas.
WHO grade I pilocytic astrocytomas and grade II diffuse astrocytomas are considered low grade, whereas the highly malignant forms, grade III anaplastic astrocytomas and grade IV glioblastoma multiforme (GBM), are high grade.
was diagnosed with pilocytic astrocytoma, a childhood brain tumor in June 2011.
However, the juvenile pilocytic astrocytoma tumour would continue to grow and be fatal if not treated.
Quality of life assessments in patients who had been surgically treated for cerebellar pilocytic astrocytoma in childhood.
An exception is the pilocytic astrocytoma (WHO grade I), the most common pediatric glioma, which is relatively well demarcated from the surrounding tissues and can be resected.
Given an association with piloid gliosis and abundance of Rosenthal fibers, even an old, often superficially located pilocytic astrocytoma with abundance of calcifications enters into the differential.
Pilocytic astrocytoma has been long recognized as a distinct entity, and it is classified in the WHO system as a grade 1 tumor.
The characteristic papillary architecture and bipartite (astrocytic and neuronal/neurocytic) cell populations distinguish this lesion from other tumors with which it shares histologic features such as dysembryoplastic neuroepithelial tumor, extraventricular neurocytoma, pilocytic astrocytoma, oligodendroglioma, and astroblastoma.
Anne/Mayo Grade WHO Designation Designation Histologic Criteria I Pilocytic astrocytoma II Astrocytoma (low Astrocytoma, One criterion, usually grade) grade 2 nuclear atypia III Anaplastic astrocy- Astrocytoma, Two criteria, usually toma grade 3 nuclear atypia and mitoses IV Glioblastoma multi- Astrocytoma, Three criteria, forme grade 4 usually nuclear atypia, mitoses, and endothelial proliferationi and/or necrosis