title: Histological evaluation of ureteral involvement in women with deep infiltrating endometriosis: analysis of a large series.
abstract: OBJECTIVE
  In women with deeply infiltrating endometriosis (DIE) what is the prevalence of involvement of endometriotic tissue and fibrosis in ureteral endometriosis (UE), as assessed by histological staining?
  
  
  CONCLUSIONS
  In women with DIE, ureteral involvement is more often due to endometriotic tissue rather than fibrosis.
  
  
  BACKGROUND
  In the current literature, histological evaluation of ureteral endometriosis is mainly based on the degree of wall infiltration by endometriosis instead of the tissue composition. A few studies reported ill-defined and contradictory histological data on the tissue composition of UE.
  
  
  METHODS
  Retrospective observational study based on clinical records of women affected by DIE, laparoscopically treated for UE at a tertiary referral center, between January 2010 and March 2013. All cases of ureteral nodule excision or ureterectomy with histological examination of the specimens were included. Exclusion criteria were other identified causes of hydroureteronephrosis, medical therapy for a period of at least 3 months before surgery and previous surgery for DIE.
  
  
  METHODS
  A total of 77 patients were included in the study and among them seven (9%) presented with bilateral ureteral involvement, giving a total of 84 cases of UE available for analysis. All patients had stage IV endometriosis. According, respectively, to the presence of endometrial glands and/or stroma cells or of fibrotic tissue only, the endometriotic UE and fibrotic UE groups were compared with regard to hydroureteronephrosis at pre-operative urinary tract computerized tomography scan, type of surgical procedure performed to treat UE (nodule removal or ureterectomy), association with other locations of the disease and post-operative complications (ureteral fistula or stenosis).
  
  
  RESULTS
  For the 84 cases of UE, 65 (77%) and 19 (23%), respectively, showed endometriotic tissue and fibrotic tissue only. Presence of hydroureteronephrosis and endometriotic pattern of UE showed a significant association [endometriotic UE 44/65 (68%) versus fibrotic UE 8/19 (42%); P = 0.04]. Fibrotic pattern of UE and presence of concomitant recto-vaginal endometriosis showed a significant association [endometriotic group: 29/65 (45%) versus fibrotic group 18/19 (95%); P < 0.001].
  
  
  CONCLUSIONS
  The retrospective and monocentric (tertiary referral center) study design.
  
  
  CONCLUSIONS
  Besides the distinction between extrinsic and intrinsic UE based on the degree of wall infiltration by endometriosis, a new classification according to the histological pattern of UE could be useful for clinicians, both in the diagnostic and therapeutic fields.
  
  
  BACKGROUND
  None.
authors.affiliation: Minimally Invasive Gynecological Surgery Unit, S.Orsola Hospital, University of Bologna, Bologna, Italy renato.seracchioli@unibo.it.
authors.forename: R
authors.initials: R
authors.lastname: Seracchioli
authors.affiliation: Minimally Invasive Gynecological Surgery Unit, S.Orsola Hospital, University of Bologna, Bologna, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Raimondo
authors.affiliation: Minimally Invasive Gynecological Surgery Unit, S.Orsola Hospital, University of Bologna, Bologna, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Di Donato
authors.affiliation: Minimally Invasive Gynecological Surgery Unit, S.Orsola Hospital, University of Bologna, Bologna, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Leonardi
authors.affiliation: Minimally Invasive Gynecological Surgery Unit, S.Orsola Hospital, University of Bologna, Bologna, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Spagnolo
authors.affiliation: Department of Obstetrics and Gynecology and Reproductive Biology, S.Orsola Hospital, University of Bologna, Bologna, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Paradisi
authors.affiliation: Minimally Invasive Gynecological Surgery Unit, S.Orsola Hospital, University of Bologna, Bologna, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Montanari
authors.affiliation: Department of Anatomo-Pathology, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Caprara
authors.affiliation: Minimally Invasive Gynecological Surgery Unit, S.Orsola Hospital, University of Bologna, Bologna, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Zannoni
mesh_terms: D000328:Adult; D004715:Endometriosis / Q000503:physiopathology*; D004717:Endometrium / Q000473:pathology; D005260:Female; D005355:Fibrosis / Q000473:pathology; D006801:Humans; D010535:Laparoscopy; D015260:Neprilysin / Q000378:metabolism; D057234:Preoperative Period; D015995:Prevalence; D012189:Retrospective Studies; D016896:Treatment Outcome; D014513:Ureter / Q000473:pathology / Q000601:surgery; D014515:Ureteral Diseases / Q000601:surgery*; D014551:Urinary Tract / Q000473:pathology
chemical_list: D015260:Neprilysin
keywords: deeply infiltrating endometriosis; endometriosis; histology; hydroureteronephrosis; ureteral