Endometriomas as a marker of disease severity

STUDY OBJECTIVE: Although superficial endometriosis can be treated effectively and safely by most gynecologic surgeons, deep infiltrating disease (DIE) needs to be treated in specialist endometriosis centers. For women to be treated in the most appropriate setting, it is necessary to identify if they have DIE. DESIGN: Prospective observational study (Canadian Task Force classification II-2). SETTING: Dedicated pelvic pain clinic attracting both secondary and tertiary referrals. PATIENTS: A total of 295 women with histologically confirmed endometriosis. INTERVENTIONS: Prospective intraoperative data were collected to investigate the role of endometriomas as a marker for DIE, and in particular, rectosigmoid disease. MEASUREMENTS AND MAIN RESULTS: In all, 61 (21%) women had an endometrioma. A significantly greater proportion of women with an endometrioma had accompanying endometriotic disease affecting the bowel compared with women without an endometrioma (77% vs 21%; p<.001). A strong relationship existed between presence of endometrioma and posterior cul-de-sac obliteration, rectosigmoid disease, and involvement of the seromuscular layer of the bowel. The presence of an endometrioma significantly increased the probability of having rectosigmoid disease, with a positive likelihood ratio of 6.96 (95% CI; 4.04-12.00). However, the absence of an endometrioma did not preclude having rectosigmoid disease, with a negative likelihood ratio of 0.55 (95% CI; 0.45-0.67). CONCLUSION: Although endometriomas provide a useful marker for DIE, the absence of an endometrioma does not preclude the presence of DIE, although a significantly lower proportion of women without an endometrioma will have DIE when compared with women with an endometrioma.