[Ultrastructural study of 9 cases of cerebellar hemangioblastoma].

Ultrastructural study of 9 cases of cerebellar hemangioblastoma demonstrated the presence of three major component cells: endothelial cells, pericytes, and stromal cells. These three kinds of cells share the following similar fine features: presence of micropinocytic vesicles, lots of microfilaments, hemidesmosomes, and basement membranes. Weibel-palade bodies were found not only in the endothelial and stromal cells but also in the pericytes. We support the idea that these three kinds of cells belong to a common lineage. Ultrastructurally, pericytes show less differentiation than endothelial and stromal cells. Some transitional forms between pericytes and endothelial cells, or between pericytes and stromal cells were obtained. We suggest that pericytes probably have the capacity of being transformed to endothelial and stromal cells.