Deep, subperitoneal lesions (infiltration greater than 5 mm) are hard, fibrous lesions in which the hormone-dependent endometrial tissue is relatively little represented (15-20% of the volume of the endometriosis nodule).
These lesions have a tendency to infiltrate the surrounding organs, behaving aggressively much like tumours, leanding to the appearance of severe forms, the removal of which is increasingly difficult.
Because of their fibrous composition, and as they are not very hormone-dependent, the size of deep endometriosis nodulesllittle impacted by amenorrhea, which simply allows the disease to stabilize, but rarely to disappear.
This explains why they may be found in postmenopausal women and smptomatic despite definitive amenorrhea.