Adenomyosis: new knowledge is generating new treatment strategies.

In the early days, all mucosal invasions of abdominal organs were considered to be one pathological condition of uncertain origin, termed adenomyoma. It was only in the 1920s that endometriosis and adenomyosis were clearly separated and it took approximately 80 years to put forward a new theory reunifying their pathogenesis. Today, identification of adenomyosis is carried out exclusively through vaginal ultrasonography and MRI. These techniques have made a careful evaluation of a distinct anatomical structure and the inner myometrial layers underlying the endometrium, termed the junctional zone, possible. Adenomyosis is characterized by a homogeneous thickening of this portion of the myometrium. When this hyperplasia is associated to an alteration of spiral arterioles' angiogenesis, then both adenomyosis and endometriosis may develop. Evidence is being accumulated that pre-eclampsia, fetal growth restriction and premature delivery may be linked, together representing a new, major obstetrical syndrome characterized by a modified uterine environment around the time of nidation. A dozen different medical or surgical techniques are utilized for the treatment of adenomyosis and novel approaches are being tested. These include use of inhibitors of angiogenesis that have been shown to cause reduced neo-angiogenesis, a significant modification of gene expression and a decrease in the percentage of active lesions. Encouraging results have also been obtained with the levonorgestrel-releasing intrauterine system.