%0 Journal Article
%T Brachyury: A Diagnostic Marker for the Differential Diagnosis of Chordoma and Hemangioblastoma versus Neoplastic Histological Mimickers
%A Valeria Barresi
%A Antonio Ieni
%A Giovanni Branca
%A Giovanni Tuccari
%J Disease Markers
%D 2014
%R 10.1155/2014/514753
%X Brachyury is a transcription factor which is required for posterior mesoderm formation and differentiation as well as for notochord development during embryogenesis. Due to its expression in the neoplastic cells of chordoma, a malignant tumour deriving from notochordal remnants, but not in tumors showing a similar histology, brachyury has been proposed as a diagnostic marker of this neoplasia. Though commonly considered a hallmark of chordoma, the expression of brachyury has been also documented in the stromal cells of hemangioblastoma (HBL), a slow growing tumor which may involve the central nervous system (CNS) and, rarely, the kidney. Herein we review the role of brachyury immunohistochemical detection in the identification and differential diagnosis of chordoma and HBL towards histological mimickers and suggest that brachyury is added to the panel of immunohistochemical markers for the recognition of HBL in routinary practice, principally in unusual sites. 1. Introduction Brachyury is a transcription factor encoded by T, a member of the T-box gene family, and required for posterior mesoderm formation and differentiation [1] as well as for notochord development [2]. In accordance with its function, brachyury is expressed in all nascent mesoderm [2, 3], in the embryo. Along with embryonic differentiation, it is downregulated [2, 3], restricted into the notochord and the tail bud [1], and then lost, when notochordal cells are replaced by bone in the vertebral bodies and by the nucleus pulposus in the intervertebral discs [4]. In the adult, brachyury expression has been found in chordoma [4], a malignant tumor which recapitulates notochord and derives from small collections of notochordal cells which may persist into the adult life [5]. Several studies have shown that brachyury represents a specific marker for chordoma, useful to discriminate this neoplasia from others with a similar histology [4¨C12]. Nonetheless, there is evidence that chordoma is not the only tumour expressing brachyury. Indeed, the expression of this protein has been also documented in hemangioblastoma (HBL) [6, 7, 13, 14], a slow growing vascular tumour, which origins from mesoderm derived, embryologically arrested hemangioblasts [4, 13], which also express this protein [15]. Herein, the use of brachyury immunohistochemical staining for the differential diagnosis of chordoma and HBL towards neoplastic histological mimickers occurring in the same sites is discussed. 2. Brachyury for the Differential Diagnosis of Chordoma Chordoma is an intraosseous, low to intermediate grade,
%U http://www.hindawi.com/journals/dm/2014/514753/