Subtle as well as typical endometriosis is seen in this view of the cul de sac and uterosacral ligaments. The uterosacral ligaments are clearly seen as vertical bands of tissue since the uterus is being put on stretch. If you look closely, you can see black lesions of endometriosis near the top of each ligament. If you look even more closely, however, you can see that each ligament is involved by subtle white fibrosis indicating moderately invasive endometriosis in each ligament. Looking closer still, you can see small white islands of endometriosis near each ligament (one is indicated by an arrow). Surgeons looking only for "black powderburn" lesions would miss most of the disease in this pelvis. The patient would continue to hurt, and the doctor would think that she had a very "resistant" case of endometriosis.