ESR1 and neoplasm: Definitive diagnosis requires histopathological evaluation of the entire tumor and its interface with adjacent myometrium, as well as an immunohistochemica assessment, LG-ESS being positive for CD10 [21,22], IFITM1 [22], WT1, ER, PR, several specific keratins, smooth muscle markers, sex cord markers, as well as Beta catenin [23].