title: Histomorphological changes in endometriosis in a patient treated with ulipristal: A case report.
abstract: BACKGROUND
  Selective progesterone receptor modulators have shown efficacy in the treatment of endometriosis, however they are not currently licensed in Canada for this purpose. Their histomorphological effects have been well documented in the endometrium, but not in endometriosis.
  
  
  METHODS
  The patient presented with uterine fibroids and heavy menstrual bleeding, and was treated with ulipristal acetate over three 90-day courses. She eventually elected to undergo definitive surgical management. On pathological examination, she was found to have a focus of endometriosis in the para-tubal soft tissue showing a morphology similar to progesterone receptor modulator associated endometrial changes (PAEC).
  
  
  CONCLUSIONS
  To our knowledge this is the first reported case of PAEC involving a focus of endometriosis. This case demonstrates histomorphological evidence of the effects of ulipristal acetate on endometriosis, and thus provides evidence of a pharmacological effect.
authors.affiliation: Department of Pathology and Laboratory Medicine, The Ottawa Hospital and University of Ottawa, Ottawa, ON, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Bateman
authors.affiliation: Department of Obstetrics, Gynecology and Newborn Care, The Ottawa Hospital, Ottawa, ON, Canada.
authors.forename: O
authors.initials: O
authors.lastname: Bougie
authors.affiliation: Department of Obstetrics, Gynecology and Newborn Care, The Ottawa Hospital, Ottawa, ON, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Singh
authors.affiliation: Department of Pathology and Laboratory Medicine, The Ottawa Hospital and University of Ottawa, General Campus, Ottawa, ON, Canada. Electronic address: sislam@toh.on.ca.
authors.forename: S
authors.initials: S
authors.lastname: Islam
mesh_terms: D000328:Adult; D004715:Endometriosis / Q000188:drug therapy / Q000473:pathology*; D004717:Endometrium / Q000187:drug effects / Q000473:pathology*; D005260:Female; D006801:Humans; D007889:Leiomyoma / Q000188:drug therapy / Q000473:pathology*; D009649:Norpregnadienes / Q000494:pharmacology / Q000627:therapeutic use*; D014594:Uterine Neoplasms / Q000188:drug therapy / Q000473:pathology*
chemical_list: D009649:Norpregnadienes; C555622:ulipristal acetate