Anatomic Significance of a Positive Barium Enema in Deep Infiltrating Endometriosis of the Large Bowel

The anatomopathological significance of a positive double-contrast barium enema (DCBE) for suspicion of deep infiltrating endometriosis of the large bowel was studied. This is a retrospective study of a prospective database. A large-bowel resection was proposed for patients who were suspicious for large-bowel endometriosis and had a positive DCBE. In a series of 73 patients, 71 large-bowel resections were performed. Histology and immunohistochemistry with the monoclonal antibody CD-10 were performed on the resection specimen. Outcome measures were the length of the resected specimen, the largest diameter of the lesion, the positivity of the resection margins, and the degree of infiltration of the large bowel. We also compared the mean largest diameters of the lesions with the degree of infiltration of the large bowel. Between December 1997 and October 2005, 80 patients were suspicious for large-bowel endometriosis: 73 (91%) had positive DCBEs, and 7 (9%) had negative DCBEs. Of the 73 with positive DCBEs, 4 (5%) refused digestive resection and 1 (1.4%) was excluded. Three patients underwent two large-bowel resections because of the presence of bifocal lesions (left and right colon). A total of 71 resections were performed. In case of positive DCBE, the perivisceral fat and the whole muscularis were infiltrated in 100% of cases. The infiltration reached the submucosa and the mucosa respectively in 82% and 18% of cases. A total of 9.9% of resection margins were positive at histology but only focally. The mean largest diameter of the lesions infiltrating the whole thickness of the large bowel was not statistically different from the mean largest diameter of more superficial lesions. Findings of mass effect with indentations and ridging of the mucosa on DCBE in a setting suspicious for large-bowel endometriosis correspond well with pathologic findings of deep infiltration of the large-bowel wall. Clinicians dealing with deep infiltrating endometriosis should be aware of these findings, which could influence their choice of surgical treatment.