MENINGOTHELIAL MENINGIOMA WITH AMIANTHOID FIBERS - CASE-REPORT WITH ULTRASTRUCTURAL-STUDY

The case of a meningothelial meningioma with 'amianthoid' fibers in a 48-year-old woman is presented. By light microscopy the tumor showed the typical features of meningothelial meningioma and rounded, deeply eosinophilic, and fibrillary areas, especially around and/or in the vicinity of blood vessels. These fibers are also called 'amianthoid' fibers. Ultrastructurally, these foci were made up of disorderly arranged and interwaving mature collagen fibrils with a variable width between 40 and 190 nm. No evidence of intracellular collagen synthesis by the tumor cells was found. The presence of 'amianthoid' fibers does not seem to carry any prognostic significance.