Related Experiment Videos
Globular glial fibrillary acidic protein-reactive cytoplasmic inclusions in ependymoma: an immunoelectron-microscopic
J L Twiss1, L J Anderson, D S Horoupian
1Department of Pathology (Neuropathology), Stanford University Medical Center, CA 94305.
Abstract:
We report of a 27-month-old boy with a recurrent infratentorial ependymoma; the initial resection was at 14 months of age. Both resection specimens were histologically similar. In addition to neoplastic ependymal cells forming perivascular pseudo-rosettes, a second population of cells with identical nuclear morphology displayed large hyaline, refractile cytoplasmic inclusion, causing these cells to superficially resemble gemistocytic astrocytes. These inclusions demonstrated strong glial fibrillary acidic protein (GFAP) immunoreactivity. Ultrastructurally, the inclusions appeared as fenestrated irregular-shaped bodies with jagged edges and were made up of electron-dense granular material. Although these inclusions superficially resembled Rosenthal fibers, immunoperoxidase stains for ubiquitin and alpha B-crystallin were negative. Immunoelectron microscopy showed that these unusual non-filamentous inclusions were diffusely GFAP positive.
Insights
This study details a rare pediatric brain tumor, infratentorial ependymoma, in a young boy. Researchers identified unusual cytoplasmic inclusions in tumor cells, which were strongly positive for glial fibrillary acidic protein (GFAP).
Area of Science:
- Neuro-oncology
- Pediatric pathology
- Cellular biology
Background:
- Ependymomas are tumors arising from ependymal cells, often found in the posterior fossa (infratentorial) of children.
- Recurrent pediatric brain tumors present significant treatment challenges.
- Accurate histological classification is crucial for diagnosis and prognosis.
Observation:
- A 27-month-old boy presented with recurrent infratentorial ependymoma.
- Histological examination revealed neoplastic ependymal cells forming perivascular pseudo-rosettes.
- A second cell population exhibited unique hyaline cytoplasmic inclusions, mimicking gemistocytic astrocytes.
Findings:
- These cytoplasmic inclusions showed strong immunoreactivity for glial fibrillary acidic protein (GFAP).
- Ultrastructural analysis described the inclusions as irregular, fenestrated bodies composed of electron-dense granular material.
- Immunohistochemistry for ubiquitin and alpha B-crystallin was negative, differentiating them from Rosenthal fibers.
- Immunoelectron microscopy confirmed these unusual, non-filamentous inclusions were diffusely GFAP positive.
Implications:
- The presence of GFAP-positive cytoplasmic inclusions represents a novel histological feature in ependymoma.
- This finding may refine diagnostic criteria and understanding of ependymoma cell differentiation.
- Further research into the nature and origin of these inclusions could offer new therapeutic targets.