XXXX : a histopathological and molecular analysis of a rare @entity511 subtype.

@entity511 @entity986 @entity5 @entity996 @entity7465 @entity8985 @entity18215 @entity876 @entity818
AIMS: @entity511 is a rare, malignant @entity5 originating from the periosteal surface of bone. We collected 38 cases from the archives of the Netherlands Committee on Bone Tumours, with the aim of studying histological features and evaluating the involvement of @entity818 ( @entity818 ), EXT, Wnt/b-catenin, the @entity996 pathway ( @entity8985 and @entity986 ), and the @entity876 pathway ( @entity876 and @entity7465 ). METHODS AND RESULTS: Histology showed a moderately cellular matrix with mucoid-myxoid changes and, in 42% of cases, formation of a neocortex. Occasional intramedullary extension (26%) and subsequent host bone entrapment (40%) were seen. Histological grading revealed grade 1 (53%) and grade 2 (45%). The @entity18215 protein was normally expressed, and mutations in @entity818 were observed in only 15% of cases. @entity996 signalling was deregulated by loss of @entity986 expression in 50% of cases, and Wnt signalling was lost in 89%. No alterations were found in @entity8985 , @entity876 , or @entity7465 . CONCLUSIONS: We report the first large histological and molecular study on @entity511 showing that histopathological examination and molecular aberrations do not predict prognosis. Although the mutation frequency of @entity818 was low, we confirm the supposed relationship with central @entity511 . Moreover, we identify loss of canonical Wnt signalling and deregulation of @entity996 signalling as possible events contributing to its histogenesis.
