A Case of Extra-Skeletal Intracranial Chondromass: Ultrastructure and Immunohistochemical Features

Abstract

The discrete microvasculature environment of the perivascular cell plays a dominant role in regulating stem cell activity and its proliferation behavior. Mesenchymal stem cells (MSC) reside in perivascular compartment, hence have the potential to contribute to the pathogenesis of extra-skeletal intracranial chondroma (ESICC). In this case report, for the first time, the immunohistochemical (IHC) markers and transmission electron microscpoe (TEM) features of perivascular cell are presented in ESICC. Microscopic examination revealed a well-differentiated chondroma with foci of ossification and islands of vacuolated-cells encircling thin-walled capillaries. TEM showed transitional morphological features suggestive of transformation to chondrocytes, with vacuolated cells. A subpopulation of spindle vacuolated-cells displayed reaction for S-100, ferritin, trypsin-anti-chymotrypsin and Vimentin. As there was no evidence of transitional forms to arachnoid cells, it can be concluded that the origin of the recognized ICC is a perivascular multipotential mesenchymal cell, MSC.