title: Arias-Stella reaction as a diagnostic pitfall in a bladder biopsy with endometriosis: case report and review of the pseudoneoplastic bladder lesions.
abstract: Arias-Stella reaction is a hormone-induced atypical endometrial change that may involve endometrial, extraendometrial, or endometriotic sites. Establishing a correct diagnosis of Arias-Stella reaction may sometimes be problematic when seen outside of the uterine corpus, particularly in a limited biopsy sample when the pathologist is not aware of the clinical history. We report an Arias-Stella reaction in bladder endometriosis, which presented as a bladder mass in a 25-year-old pregnant woman. Clinical information of intrauterine pregnancy (week 16) was not initially provided when the biopsy was performed. We also discuss endometriosis, endocervicosis, and müllerianosis of the bladder, which are benign glandular lesions that may mimic tumors within the bladder wall.
authors.affiliation: Department of Pathology and Laboratory Medicine, Calgary Laboratory Services, University of Calgary, Alberta, Canada. kiril.trpkov@cls.ab.ca
authors.forename: Kiril
authors.initials: K
authors.lastname: Trpkov
authors.forename: Kelly
authors.initials: K
authors.lastname: Guggisberg
authors.forename: Asli
authors.initials: A
authors.lastname: Yilmaz
mesh_terms: D000328:Adult; D001706:Biopsy; D003937:Diagnosis, Differential; D004715:Endometriosis / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000473:pathology* / Q000601:surgery; D001745:Urinary Bladder Diseases / Q000473:pathology* / Q000601:surgery; D001749:Urinary Bladder Neoplasms / Q000473:pathology