Multiple lesions of endometriosis in the small intestine treated by the shaving technique: A case report

A 30-year-old nulliparous woman presented with intense dyspareunia, severe pelvic pain (pain score of 9/10), and alternating diarrhea and constipation. She had had frequent pre-menstrual and menstrual nausea since adolescence and worsening menstrual cramps over the last 3 years, with abdominal distension, previously diagnosed as irritable bowel syndrome (IBS) and intestinal dysbiosis. She was infertile, having not conceived over the course of 3 years without contraception. Symptoms like distension, nausea, and vomiting during menstruation may be related to small intestine lesions and confused with IBS or dysbiosis. Physical exam showed typical findings for parametrial and retrocervical endometriosis, with the uterine cervix deviated left and a palpable nodule adhering to the rectum at vaginal fundus. Deep endometriosis was diagnosed by symptoms, specialized physical exam, magnetic resonance imaging (MRI), and ultrasound with bowel prep during infertility investigation. MRI revealed bilateral parametrial hypodense tissue infiltration on T2, more on the left. No small intestine lesions were detected preoperatively, only during surgery ( Fig. 1 A). Tests showed extensive pelvic endometriosis with a complex intestinal lesion in the rectosigmoid, causing pain and infertility, leading to surgery. Fig. 1 (A) Axial section of pelvic magnetic resonance image revealing a hypodense area in T2 in the parametria bilaterally. (B) Anatomopathological examination of a lesion in the small intestine showing the endometriosis removed with free margins. Fig. 1 (A) Axial section of pelvic magnetic resonance image revealing a hypodense area in T2 in the parametria bilaterally. (B) Anatomopathological examination of a lesion in the small intestine showing the endometriosis removed with free margins. During surgery, seven endometriosis lesions were found on the terminal ileum wall near the ileocecal valve, spaced 5 cm apart on the small intestine serous surface ( Fig. 2 ). Additional lesions appeared in bilateral uterine parametrium, retrocervical region, rectosigmoid anterior wall, and bilateral endometriomas. Extrapelvic lesions were found in the appendix, right iliac fossa, and right diaphragmatic dome; these were not seen in prior imaging. Fig. 2 Intraoperative aspects of endometriotic lesions in the terminal ileum. (A–B) Nodular endometriotic lesions on the serosa of the terminal ileum, located approximately 5 cm from the ileocecal valve. (C—D) Excision of the nodular lesions using cold scissors during laparoscopic surgery. (E–F) Suture of the terminal ileum wall with 3–0 PDS thread following the shaving technique. Fig. 2 Intraoperative aspects of endometriotic lesions in the terminal ileum. (A–B) Nodular endometriotic lesions on the serosa of the terminal ileum, located approximately 5 cm from the ileocecal valve. (C—D) Excision of the nodular lesions using cold scissors during laparoscopic surgery. (E–F) Suture of the terminal ileum wall with 3–0 PDS thread following the shaving technique. Surgery was done in a tertiary hospital by a gynecological surgeon experienced in video surgery and en bloc excision for endometriosis. Video laparoscopy showed endometriosis in both parametria, iliac fossae, and nodular lesions in terminal ileum ( Fig. 2 ). The procedure included en bloc resection and excision of marble-like endometriosis infiltrating connective tissue and complete posterior pelvic peritonectomy. Bilateral ureterolysis and excision of lesions involving hypogastric nerves were performed. Hypogastric fasciae were preserved for neuroprotection. A 2.5 cm rectal anterior wall lesion was resected by discoid excision. Seven superficial endometriotic implants on terminal ileum serosa were shaved and coagulated. An appendectomy was also performed due to endometriosis identified near the cecum. A 60 mm linear stapler was used for the resection, in conjunction with peritonectomy of the right iliac fossa — an area frequently affected by endometriosis due to embryological factors ( Fig. 3 , Fig. 4 ). Fig. 3 En bloc excision of deep pelvic and iliac fossa endometriosis. (A–B) Initial pelvic view showing endometriosis involvement. (C) En bloc excision of endometriosis. (D) Final result after en bloc excision. (E) Right iliac fossa affected by endometriosis. (F) En bloc excision and peritonectomy of the right iliac fossa. Fig. 3 Fig. 4 Discoid resection of the rectum using a circular stapler. (A) Delineation of the anterior rectal wall for discoid excision using a circular stapler. (B—C) Closure of the circular stapler and discoid resection. (D) Final result after discoid rectal resection. (E) Delineation of the anterior rectal wall for discoid excision using a circular stapler. (F–G) Closure of the circular stapler and discoid resection. (H) Final result after discoid rectal resection. Fig. 4 En bloc excision of deep pelvic and iliac fossa endometriosis. (A–B) Initial pelvic view showing endometriosis involvement. (C) En bloc excision of endometriosis. (D) Final result after en bloc excision. (E) Right iliac fossa affected by endometriosis. (F) En bloc excision and peritonectomy of the right iliac fossa. Discoid resection of the rectum using a circular stapler. (A) Delineation of the anterior rectal wall for discoid excision using a circular stapler. (B—C) Closure of the circular stapler and discoid resection. (D) Final result after discoid rectal resection. (E) Delineation of the anterior rectal wall for discoid excision using a circular stapler. (F–G) Closure of the circular stapler and discoid resection. (H) Final result after discoid rectal resection. Furthermore, a lesion involving the right diaphragmatic dome was excised using the en bloc technique. Access to the thoracic cavity was achieved, allowing full-thickness resection, barbed suture closure of the diaphragmatic defect, and thoracic cavity decompression through aspiration of the pneumothorax. Histopathology confirmed endometriosis in all lesions ( Fig. 1 B). No postoperative complications occurred, showing safety, efficacy, and reproducibility of shaving, discoid resection, and appendectomy techniques. Eighteen-month follow-up showed no symptom recurrence or progression.

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Written informed consent was obtained from the patient to publish this case report and the accompanying images.

Endometriosis of the small intestine represents a rare and challenging manifestation of this chronic gynecological disease, accounting for approximately 2 % to 16 % of cases of intestinal endometriosis, second only to the sigmoid colon, which is the most frequently affected site [ 5 ]. In clinical terms, this form of endometriosis can be asymptomatic or present non-specific symptoms such as abdominal pain, distension, altered bowel habits, nausea, vomiting, and, in more severe cases, signs of intestinal obstruction [ 1 ]. Recent studies on pathogenesis propose various theories. Signorile et al. suggest minor embryogenesis defects cause endometriosis, with abnormal Müllerian ducts leading to aberrant cell migration or differentiation along fetal organogenesis pathways [ 6 ]. This suggests an embryological origin rather than the condition being solely acquired during reproductive life. The posterior compartment is involved in 90 % of deep endometriosis cases [ 1 , 3 ]. Symptoms depend on lesion location, extent, and immune response, commonly including dysmenorrhea and chronic pelvic pain [ 2 ]. Intestinal symptoms like pain, distension, and bowel changes often mimic IBS and small intestinal bacterial overgrowth (SIBO). Endometriosis causes inflammatory and desorptive intestinal mucosa changes impairing permeability; Shanti et al. reported this in 45 % of patients [ 7 ]. Sakiris et al. highlight that ileal endometriosis can mimic other diseases like Crohn's, due to overlapping signs such as ileal stenoses and intermittent gastrointestinal bleeding [ 8 ]. In one case, multiple ulcerated stenoses in the distal ileum were first misdiagnosed as NSAID-induced enteropathy, delaying diagnosis. Another case showed recurrent intestinal obstruction with chronic inflammation, later confirmed as endometriosis after surgery. These cases stress the need for careful histopathology to accurately differentiate diagnoses, especially with persistent gastrointestinal symptoms and unclear tests. Small intestine endometriosis mainly affects the serosa, with deposits usually under 2 cm. Though often asymptomatic, it can cause chronic inflammation leading to fibrosis, a main cause of gastrointestinal symptoms [ 9 ]. Disease spread beyond the serosa may cause severe issues like rectal bleeding, intestinal obstruction, and tumor-like masses [ 10 ]. Rarely, it can progress to intussusception, malignant transformation, or intestinal perforation [ 11 ]. Kobayashi et al. described a rare case of endometriosis involving both the appendix and the terminal ileum, with intestinal obstruction, which was initially mistaken for a malignant tumor, leading to ileocecal resection with lymph node dissection [ 12 ]. This case highlights the diagnostic complexity of intestinal endometriosis, which can mimic malignant processes and requires careful surgical management. Endometriosis etiology is multifactorial, with an embryological origin linked to Müller ducts and intestinal rotations during formation of the digestive tract [ 7 ]. This concept, more relevant than Sampson's theory, shows infiltration along pelvic layers like hypogastric and presacral fasciae, where bruising and fibrosis drive progression [ 13 ]. The disease follows a Müllerian embryonic path, aligned with colon formation during gastrulation, explaining pelvic and right diaphragm presence near the heart. Endometriosis forms extensive “marble-like” connective tissue lesions, not superficial spots ( Fig. 5 ). Laparoscopic en bloc peritonectomy with an ultrasonic device is beneficial. Fig. 5 Diagram of the embryological defect in Müllerian duct development during the embryonic period, likely causing endometriosis in the Müllerian pathtrack. Fig. 5 Diagram of the embryological defect in Müllerian duct development during the embryonic period, likely causing endometriosis in the Müllerian pathtrack. Early diagnosis of intestinal endometriosis is challenging, as seen in this case, and should be considered in young women with pelvic endometriosis. Computerized tomography (CT) may show disorganization and thickening of the muscularis mucosa of the bowel wall, but rarely confirms disease [ 14 ]. MRI and rectal ultrasound have high sensitivity (77–90 %) and negative predictive value (92–100 %) but lower specificity and positive predictive value [ 15 ]. Imaging before surgery showed low sensitivity for small intestine and extrapelvic lesions; ileal lesions appeared only during laparoscopy, with no extrapelvic lesions identified, highlighting detection limits [ 13 ]. Saqib et al. emphasize that CT, colonoscopy, and MRI often miss minor bowel endometriosis, delaying diagnosis until laparoscopy [ 8 ]. Although imaging can suggest intestinal endometriosis, laparoscopy remains the gold standard for definitive diagnosis and treatment of lesions in the intestinal wall, as it allows visualization of the abdominal and pelvic organs [ 16 ]. In the described case, diagnostic laparoscopy confirmed the diagnosis of intestinal endometriosis, allowing for the resection of the lesions for treatment. En bloc peritonectomy of the posterior pelvic compartment, done laparoscopically or robotically, is an innovative technique removing peritoneum and fascia while preserving nerve plexuses. Dückelmann reported favorable results in symptom relief and fertility [ 17 ]. The rectosigmoid colon is the most common intestinal site. Lesions may be superficial or infiltrative, causing various symptoms. Intestinal obstruction is a serious complication requiring surgery to restore anatomy and function [ 4 ]. Surgical treatment varies by lesion size, depth, and features [ 4 ]. Common techniques include shaving, discoid excision, and segmental resection [ 18 ]. Shaving suits superficial serosal lesions, dissecting wall without lumen breach [ 4 ]. Discoid resection using a circular stapler is suitable for submucosal fibrosis and low rectum lesions [ 18 ]. Segmental resection removes affected intestine with primary anastomosis but should be avoided near the rectum due to a higher complication risk there compared with shaving or discoid excision [ 19 ]. Koyama et al. describe a case of small bowel obstruction secondary to ileal endometriosis with appendicular and lymph node involvement, successfully treated by single-incision laparoscopic surgery [ 20 ]. This minimally invasive technique, which utilizes a single small umbilical incision, offers aesthetic advantages and a faster postoperative recovery, especially in young patients. Additionally, this approach enables excellent visualization and precise surgical management of the lesions, making it a safe and effective option for complex cases. The present case shows that when endometriosis not only affects the reproductive organs but also involve gastrointestinal sites due to Müller's ducts and gastrulation it requires symptom-focused evaluation, and responds well to shaving and laparoscopic en bloc excision.

This article was not commissioned and was peer reviewed.

Igor Chiminacio contributed to patient care, conception of the case report, drafting the manuscript, undertaking the literature review and revising the article critically for important intellectual content. João Francisco Petry contributed to patient care and assisted with the literature review. Nataly Nunes Ladeira Ramalho Verissimo Campos contributed to patient care and assisted with the literature review. Carolina Obrzut contributed to patient care and assisted with the literature review. All authors approved the final submitted manuscript.

Endometriosis is characterized by the presence of endometrium-like tissue outside the uterus. Its estimated prevalence is up to 20 % among women of reproductive age and may be higher considering the prevalence of menstrual cramps, often a sign of ectopic endometrium [ 1 ]. It is estimated that up to 40 % of infertile women have endometriosis and menstrual cramps are reported by up to 70 % of adolescents. The association of pelvic pain, irritable bowel symptoms, and infertility has a high predictive value for endometriosis [ 2 ]. Anatomical locations, such as the pelvis and abdomen, suggest its origin in the embryonic leaflets, especially in the uterine parametrium, ureteral pathway, right iliac fossa, and diaphragm. In the small intestine, it may be associated with defects in the ducts of Muller during gastrulation [ 3 ]. Intestinal obstruction is uncommon, especially in the ileum [ 1 , 3 ], with only 23 % of cases involving this region [ 4 ]. This case report describes a rare presentation of endometriosis in the small intestine, with seven nearby lesions.

The authors declare that they have no conflict of interest regarding the publication of this case report.