tuberculum sellae tuberculum sellae the tuberculum sellae (or the tubercle of the sella turcica) is a part of the sphenoid bone that is an elevation behind the chiasmatic groove. a variable slight to prominent median elevation forming the posterior boundary of the chiasmatic groove and the anterior boundary of the hypophysial fossa. tuberculum sellaesphenoid bone. upper surface. (tuberculum sellae visible at center.)base of the skull. upper surface. (sphenoid bone visible in yellow, the tuberculum sellae is labeled at the right, fourth from the top of the yellow section.)identifiersta98a02.1.05.007ta2590fma54719anatomical terminology additional images tuberculum sellae