Diagnosis of endometriosis.

The diagnosis of endometriosis is based on the presence of endometrial-like tissue outside the uterine cavity and direct or indirect evidence of cyclic bleeding. Clinically three entities can be distinguished: the peritoneal implant, the endometrial cyst and the deep-nodular lesion. Laparoscopy and biopsy remain the gold standard for diagnosis, but in addition attention should be paid to the detection of functional activity, such as bleeding, by non-invasive techniques.