Arias-Stella reaction of the cervix: The enduring diagnostic challenge

Background: The Arias-Stella reaction is a hormone-related atypical endometrial change characterized by hypertrophy and vacuolization of glandular epithelial cells, associated with marked nuclear pleomorphism, enlargement, and hyperchromasia. When presenting in extra-uterine sites, the differentiation of Arias-Stella changes from other more ominous clear cell lesions may pose significant difficulties.