T. Bohling et al., DIFFERENT EXPRESSION OF ADHESION MOLECULES ON STROMAL CELLS AND ENDOTHELIAL-CELLS OF CAPILLARY HEMANGIOBLASTOMA, Acta Neuropathologica, 92(5), 1996, pp. 461-466
Cell-cell and cell-matrix interactions are essential for many basic fu
nctions, including differentiation and development. In pathological co
nditions such as inflammation and tumorigenesis adhesive events also p
lay a major role. Cellular adhesion is mediated by specific molecules
expressed by both normal and neoplastic tissues. Capillary hemangiobla
stoma is a tumor of controversial origin, characterized by two major c
omponents, vacuolated stromal cells and a capillary network. In order
to shed light on the differentiation of the stromal cells and the inte
ractions between the two major components of hemangioblastoma we studi
ed the expression of several adhesion molecules by immunocytochemistry
. The endothelium-associated adhesion molecules (ICAM-1, ICAM-2, VCAM-
1, PECAM-1 and ELAM-1) were expressed by endothelial cells within the
tumors, but not by stromal cells. In contrast, the stromal cells showe
d strong neuronal cell adhesion molecule (NCAM/CD56) expression, furth
er distinguishing them from endothelial cells. In addition, the stroma
l cells expressed CD44, which is of interest, as this membrane protein
is linked to ezrin, a cytoskeleton-associated protein also expressed
by stromal cells. We conclude that the stromal cells and endothelial c
ells of capillary hemangioblastoma exhibit quite divergent expression
patterns of adhesion molecules. The NCAM expression in stromal cells s
uggests neuroectodermal or mesenchymal differentiation of this tumor.
In addition, the NCAM expression could contribute to the sometimes pro
blematic differential diagnosis between capillary hemangioblastoma and
metastatic renal cell carcinoma of the central nervous system.