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Filamentous aggregates in a meningioma

V Jay1, V Edwards

  • 1Department of Pathology, Hospital for Sick Children, University of Toronto, Canada.

Ultrastructural Pathology
|November 1, 1996
PubMed

Insights

This study describes unique filamentous aggregates found in a young boy's atypical meningioma. These structures contain intermediate filaments and extracellular matrix proteins, suggesting active tumor cell synthesis and release.

Area of Science:

  • Neuropathology
  • Oncology
  • Cell Biology

Background:

  • Meningiomas are tumors arising from the meninges.
  • Atypical meningiomas represent a subset with increased proliferative potential.
  • Understanding tumor composition aids in diagnosis and treatment.

Observation:

  • Unusual filamentous aggregates were observed in a pediatric atypical meningioma.
  • Light microscopy revealed Rosenthal fiber-like structures, both intra- and extracellularly.
  • Immunohistochemistry showed positivity for vimentin, laminin, and collagen type IV.

Findings:

  • Ultrastructural analysis indicated aggregates of tangled filaments with electron-dense condensations.
  • Intracellular aggregates were membrane-bound, some within the rough endoplasmic reticulum.
  • Extracellular aggregates filled spaces between tumor cells, suggesting active synthesis and secretion.

Implications:

  • These novel inclusions are composed of intermediate filaments (vimentin) and extracellular matrix proteins.
  • The findings suggest active synthesis within tumor cells and subsequent release into the extracellular space.
  • This characterization provides new insights into the pathogenesis of atypical meningiomas.

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