Ultrastructural Features of Pleomorphic Xanthoastrocytoma: A Comparative Study with Glioblastoma Multiforme
| Autor: | Caterina Giannini, Bernd W. Scheithauer, Takanori Hirose |
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| Rok vydání: | 2001 |
| Předmět: |
Organelles
Pleomorphic xanthoastrocytoma Pathology medicine.medical_specialty Brain Neoplasms Astrocytic Tumor Hemidesmosome Astrocytoma Biology medicine.disease Lipids Pathology and Forensic Medicine Neuroepithelial cell medicine.anatomical_structure Structural Biology Astrocytes Lipid droplet medicine Ultrastructure Humans Basal lamina Glioblastoma Intermediate filament |
| Zdroj: | Ultrastructural Pathology. 25:469-478 |
| ISSN: | 1521-0758 0191-3123 |
| Popis: | Eighteen tumors (15 cases) were ultrastructurally examined and compared to 11 examples of glioblastoma multiforme (GBM) [to determine the cellular nature of pleomorphic xanthoastrocytoma (PXA).] PXA, as well as GBM, were principally composed of pleomorphic astrocytes containing numerous intermediate filaments. Lipid droplets, lysosomes, and basal laminas were more numerous and fully developed in PXA, but were not specific to the tumor. Aggregates of secondary lysosomes, light microscopically evident as eosinophilic granular bodies, and ribosome-lamella complexes were exclusively seen in PXA. Also noted in PXA were centrioles, occasional Rosenthal fibers, hemidesmosomes in small number, rudimentary cell junctions, and interstitial calcifications. In addition to astrocytic constituents, 20% of PXA contained cells with neuronal features, as evidenced by the presence of dense-core granules, microtubules, and clear vesicles. In contrast, GBMs consisted solely of astrocytic cells. In the present study, the salient ultrastructural findings of PXA were largely degenerative in nature, including numerous lipid droplets and secondary lysosomes, as well as basal laminas, ribosome-lamella complexes, and occasional neuronal differentiation. The presence of basal lamina does not necessarily imply a histogenetic derivation from subpial astrocytes, in that it is also a common feature of GBM. Given the occurrence of biphenotypic, glioneuronal differentiation in some cases, PXA may be derived from a neuroepithelial stem cell. The authors conclude that PXA is fundamentally an astrocytic tumor, albeit one with a significant tendency to undergo neuronal differentiation. |
| Databáze: | OpenAIRE |
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