Endoglin (CD105) expression in neurofibromatosis type 2 vestibular schwannoma.

Background Neurofibromatosis type 2 (NF2) is an autosomal dominant, multiple neoplasia syndrome characterized by bilateral vestibular schwannomas (VSs). Endoglin is a proliferation-associated protein expressed in angiogenic endothelial cells. The aim of this study was to investigate endoglin expression in a series of NF2-associated VSs, as compared with a group of sporadic VSs. Methods Using image analysis, vessel cross-sectional area (AA) and density (VD) were calculated from CD105 expression in 7 NF2-associated VSs and 14 size-matched sporadic VSs. Results There were no significant differences between NF2-associated VSs and sporadic cases in terms of AA (P = .28), or VD (P = .39). A positive correlation emerged between tumor growth rate (measured on contrast-enhanced MRI) and VD in the cohort of NF2-associated VSs (rho = 0.95, P = .05). Conclusions Further investigations are needed to ascertain the feasibility of (a) measuring circulating endoglin levels to monitor tumor growth rate and (b) targeting tumor neoangiogenesis with anti-endoglin approaches in NF2-associated VS.