EP782 - Diagnostic accuracy of magnetic resonance imaging in the detection of intestinal endometriosis: correlation with histopathological findings

ePoster Presenter(s)

• 

  Dioselina Lanzagorta Ortega, MD (she/her/hers)

  PGY3 General Surgery Resident
  The American British Cowdray Medical Center
  American British Cowdray Medical Center
  Ciudad de México, Distrito Federal, Mexico

  Disclosure information not submitted.

Author(s)

• 

  Andric Perez-Ortiz, MD, MPH (he/him/his)

  Colorectal Surgery Fellow
  The American British Cowdry Medical Center
  The American British Cowdray Medical Center
  CDMX, Distrito Federal, Mexico

  Disclosure information not submitted.
• YK

  Yoshiki Komori Valdés, n/a

  PGY2 General Surgery Resident
  American British Cowdray Medical Center
  Mexico City, Distrito Federal, Mexico

  Disclosure information not submitted.
• LT

  Luis F Tallabs-Utrilla, Centro Médico ABC

  MD
  Centro Médico ABC
  Mexico City, Distrito Federal, Mexico

  Disclosure information not submitted.
• RB

  Ricardo A A. Beltran Mejia, n/a

  General surgery resident
  ABC Medical Center
  Ciudad de México, Distrito Federal, Mexico

  Disclosure information not submitted.
• RM

  Raul Moran Treviño, MD

  Colorectal surgery fellow
  The American British Cowdray Medical Center
  México City, Distrito Federal, Mexico

  Disclosure information not submitted.
• AZ

  Asya Zubillaga, MD

  Hospital General Dr Manuel Gea Gonzalez

  Disclosure information not submitted.
• MV

  Martín Vega de Jesus, MD, Md

  Programa Director General Surgery
  American British Cowdray Medical Center
  México, Distrito Federal, Mexico

  Disclosure information not submitted.
• EG

  Edgar A. Gonzalez Macedo, MD, Certified General Surgeon, Certified Colorectal Surgeon

  Associate professor
  ABC Medical Center
  Mexico City, Distrito Federal, Mexico

  Disclosure information not submitted.

Senior Author(s)

• JM

  Juan F. Molina López, MD, MSc, PhD

  Colorectal surgeon staff
  ABC Medical Center
  Mexico City, Distrito Federal, Mexico

  Disclosure information not submitted.

Purpose/Background: Intestinal endometriosis involving the colon and rectum represents one of the most severe and surgically challenging forms of the disease, commonly associated with pelvic pain, cyclic rectal bleeding, and infertility. Pelvic magnetic resonance imaging (MRI) plays a key role in preoperative planning. However, ongoing debate remains regarding its diagnostic accuracy compared to diagnostic laparoscopy with histopathologic confirmation, currently recognized as the gold standard. This study aims to evaluate the diagnostic performance of pelvic MRI for colorectal endometriosis, using laparoscopic and histological findings as reference standards to improve surgical planning and diagnostic pathways.

Methods/Interventions: We analyzed a subset of a retrospective endometriosis cohort (2015-2025) involving cases of deep infiltrating endometriosis requiring intestinal resection. Clinical, surgical, and histopathology data were abstracted from electronic medical records of adult women (≥18 years) who underwent laparoscopic colon and/or rectal excision. All patients had preoperative evidence of deep pelvic endometriosis on MRI. Postoperative pathology reports were reviewed for depth of invasion, from serosa to mucosa and/or adjacent structures.

Agreement between MRI findings and histopathological results was assessed using Cohen's Kappa (R v.4.2.2). Additionally, agreement between MRI, pathology, and intraoperative surgical findings was evaluated using Light's Kappa for three raters.

Results/Outcomes: Of 20 cases with deep infiltrating endometriosis, half underwent resection with primary anastomosis. The mean age at surgery was 35.2 ± 5.7 years. Most patients reported severe abdominal pain (72.2%) and abnormal uterine bleeding at presentation (55.6%).

On MRI, 70.6% of lesions involved the rectum, most limited to the serosal layer (31.25%), followed by transmural infiltration (18.8%). All patients were managed laparoscopically with intestinal resection and primary stapled colorectal anastomosis. A protective loop ileostomy was required in only one case. No immediate or delayed postoperative complications were reported. Pathology revealed that 77.8% of cases were affected up to the muscular layer, 16.7% involved only the serosa, and 5.6% showed microscopic transmural involvement.

Concordance between MRI and pathology was fair (κ = 0.28; 95% CI: 0.08-0.55; p = 0.0434). There was no agreement between intraoperative surgeon reports and pathology (κ = −0.13; 95% CI: −0.39 to 0.14; p = 0.3532). Overall inter-rater agreement (MRI, pathology, surgeon) was slight and non-significant, primarily driven by concordance between MRI and pathology (κ = 0.17; p = 0.1250).

Conclusion/Discussion: Pelvic MRI demonstrated concordance with histopathological findings in patients with deep intestinal endometriosis, primarily involving the rectum. Notably, there was no agreement between intraoperative laparoscopic observations and histology. Although the sample size was small, these findings support further investigation into the diagnostic accuracy of MRI versus intraoperative assessment, particularly for surgical decision-making in colorectal endometriosis.

Baseline Characteristics and MRI Findings in Patients with Colorectal Endometriosis
Table showing the demographic characteristics, comorbidities, symptoms, and MRI findings of intestinal involvement and depth of invasion in patients with colorectal endometriosis. MRI findings were compared with intraoperative assessment and histopathological confirmation.