Intestinal endometriosis in a 36-year-old woman
===============================================

* Yasuhiko Hamada
* Kyosuke Tanaka

A 36-year-old woman presented to the emergency department with a 9-month history of abdominal pain accompanied by rectal bleeding during menstruation. She was otherwise well. Her pelvic and rectovaginal examination, as well as findings on transvaginal ultrasound, were unremarkable. *T*2-weighted magnetic resonance imaging (MRI) showed a hypointense wall thickening in the sigmoid colon. We suspected endometriosis and our differential diagnosis included inflammatory bowel disease and cancer. Colonoscopy showed a 30-mm submucosal lesion with a red, nodular surface in the sigmoid colon (Figure 1A). Pathologic examination of biopsy specimens was nonspecific. Subsequently, biopsies performed during a second colonoscopy just before the patient’s menstrual phase showed an endometriotic gland and stroma, positive for estrogen receptor (Figure 1B). We diagnosed intestinal endometriosis. Our patient preferred to avoid long-term hormone therapy and accepted the risk associated with laparoscopic sigmoidectomy. Laparoscopic exploration showed no other endometriotic implants.

![Figure 1:](http://www.cmaj.ca/https://www.cmaj.ca/content/cmaj/192/33/E960/F1.medium.gif)

[Figure 1:](http://www.cmaj.ca/content/192/33/E960/F1)

Figure 1: 
(A) Endoscopy image showing reddish nodules (arrows) atop a 30 mm submucosal lesion in the sigmoid colon of a 36-year-old woman. (B) Biopsy image obtained just before the patient’s menstrual phase, showing a gland and stroma of endometrium (arrow) (hematoxylin and eosin stain; original magnification ×100.

Intestinal endometriosis occurs in 5%–15% of women with endometriosis, and as was the case with our patient, about 20% of women with intestinal endometriosis do not have pelvic endometriosis. 1 The rectosigmoid colon is involved in 3 out of 4 patients with intestinal endometriosis. Although MRI and transvaginal ultrasound are sensitive diagnostic modalities for intestinal endometriosis, definitive diagnosis requires a biopsy. Endoscopic biopsies frequently yield insufficient tissue because the mucosal involvement is sparse.2 We performed endoscopic biopsies just before the menstrual phase, when endometriotic tissue is at its peak. First-line treatment of endometriosis is hormonal, but surgery may be performed for severe intestinal stenosis or to accommodate a patient’s preference. The rate of recurrence after surgery is about 10%.3

## Footnotes

*   **Competing interests:** None declared.

*   This article has been peer reviewed.

*   The authors have obtained patient consent.

## References

1.  Rossini LG, Ribeiro PA, Rodrigues FC, et al. Transrectal ultrasound — Techniques and outcomes in the management of intestinal endometriosis. Endosc Ultrasound 2012;1:23–35.
    
    

2.  Bong JW, Yu CS, Lee JL, et al. Intestinal endometriosis: diagnostic ambiguities and surgical outcomes. World J Clin Cases 2019;7:441–51.
    
    

3.  Meuleman C, Tomassetti C, D’Hoore A, et al. Surgical treatment of deeply infiltrating endometriosis with colorectal involvement. Hum Reprod Update 2011;17:311–26.
    
    [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1093/humupd/dmq057&link_type=DOI) 
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=21233128&link_type=MED&atom=%2Fcmaj%2F192%2F33%2FE960.atom) 
    
    [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=000289312300003&link_type=ISI)