How common is extra-pelvic endometriosis?

Extra-pelvic endometriosis is uncommon overall. In the vast majority of people, endometriosis is confined to the pelvis (ovaries, pelvic peritoneum, bladder/ureters, rectum), and when it extends beyond that, it more often shows up higher in the abdomen—such as on the bowel or diaphragm—rather than far outside the abdomen.

Truly distant “extra-pelvic” disease (for example, inside the chest cavity or lungs—often grouped under thoracic endometriosis syndrome) is considered rare, even though it’s the most common of the rare extra-pelvic presentations. Because these cases can be overlooked, the pattern matters: symptoms that reliably flare with your cycle—like right-sided upper abdominal/shoulder/chest pain, shortness of breath, or recurrent lung collapse around menstruation—can be a clue that endometriosis may not be limited to the pelvis. If this sounds familiar, our team can help you think through your symptom pattern and plan the right evaluation and surgical strategy, including inspecting areas like the diaphragm when it’s appropriate.