The patient had an examination under anesthesia and tru-cut biopsies of the mass. A fixed submucosal mass was noted on examination. The final pathologic analysis from the biopsies demonstrated endometriosis. Endometriosis is defined as endometrial tissue outside the uterine cavity. It can affect up to 22% of women during their reproductive years and can cause chronic pelvic pain and infertility.1 About 5.4% of patients have colorectal involvement, with 76% of these patients having endometriosis in the sigmoid, rectosigmoid colon, or rectum.2 Gastrointestinal tract involvement of endometriosis is frequently asymptomatic (up to 35% of patients) but can lead to abdominal pain and distention (most common), diarrhea, constipation, tenesmus, and blood in the rectum.3,4 In patients with a personal history of endometriosis or coexistent gynecological symptoms, endometriosis should be considered in the differential diagnosis of atypical intestinal findings.
Magnetic resonance imaging and computed tomographic scans are not sensitive for identifying endometriotic lesions in the pelvis.5 Generally, endometrial tissue is very positron emission tomography avid because the tissue is marked by rapid cellular turnover. However, the degree of avidity can vary with the menstrual cycle. This case was unusual because the endometrial lesions did not have marked fludeoxyglucose uptake on positron emission tomography.
Options for treating colorectal endometriosis are dictated by the symptoms. Asymptomatic lesions can be observed. Medical treatment is the first-line therapy if the patient is not attempting to become pregnant. Options include hormone manipulation with oral contraceptives or androgens and gonadotropin-releasing hormone analogues. Most patients (85%-100%) have improvement of their symptoms with gonadotropin-releasing hormone analogue therapy, but adverse effects including bloating, weight gain, and depression are experienced by up to 85% of women and limit its utility.6 Oral contraceptives tend to be the treatment of preference because they have fewer adverse effects. Pelvic pain generally returns when medical treatment is stopped. Surgical options are either open or laparoscopic excision of the endometrial lesions and/or resection of the involved segments of intestine. Surgery is recommended either if the patient is trying to conceive or if their symptoms are refractory to medical therapy. Occasionally, endometriosis cannot be distinguished from neoplasm and, in that case, bowel resection is recommended. If pelvic endometriosis is extensive, removal of the reproductive organs should be considered concurrent with the excision of the endometrial lesions and/or bowel resection.5 The operations can be challenging and frequently require close collaboration between gynecologists and colorectal surgeons. In operative planning, it is important to consider the reproductive plans of the patient. Although postoperative complications occur in 3% to 10% of the patients, anastomotic leak is rare despite frequent low pelvic bowel anastomoses. This is probably a reflection of the fact that endometriosis tends to affect primarily younger patients. Even with resectional surgery, about 19% of patients will have recurrence of endometrial lesions at 5 years, though the risk of recurrence is less common with a bowel resection than with excision of endometrial lesions from the surface. Approximately 25% of patients will have repeat operations for recurrent pelvic pain from endometriosis.7
The patient elected for conservative management with hormonal therapy, and currently her pelvic pain is improved. She is resuming her infertility treatment and will have surgical resection if she is not able to conceive.
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Correspondence: Elizabeth Wick, MD, Department of Surgery, Johns Hopkins University, 600 N Wolfe St, Blalock 658, Baltimore, MD 21287 (firstname.lastname@example.org).
Accepted for Publication: April 27, 2009.
Author Contributions:Study concept and design: Wick. Acquisition of data: Maxey and Wick. Analysis and interpretation of data: Wick and Gearhart. Drafting of the manuscript: Maxey and Wick. Critical revision of the manuscript for important intellectual content: Wick and Gearhart. Administrative, technical, and material support: Wick. Study supervision: Wick and Gearhart.
Financial Disclosure: None reported.
Image of the Month—Diagnosis. Arch Surg. 2010;145(3):306. doi:10.1001/archsurg.2010.11-b