Myofibroblasts Are Evidence of Chronic Tissue Microtrauma at the Endometrial-Myometrial Junctional Zone in Uteri With Adenomyosis.

Background:Adenomyosis (AM) uteri exhibit hyperperistalsis. The latter causes a chronic tissue trauma at the endometrial–myometrial junctional zone (EMJZ). Upon tissue trauma, microdehiscences in the myometrium facilitate the translocation of basal endometrial fragments into the myometrium. There, a metaplasia (mediated by transforming growth factor β1 [TGFβ1] and connective tissue growth factor [CTGF]) occurs and AM lesions develop. The abundance of myofibroblasts in a tissue hallmarks metaplasia and points to a tissue microtrauma.Materials and Methods:To study if myofibroblasts—as an evidence of tissue microtrauma—are more abundant at EMJZ in AM-uteri, a case–control experimental study was carried out at Charite University Hospital—Endometriosis Research Centre. In all, 18 uteri with AM and 14 uteri without AM were obtained during laparoscopy-assisted vaginal hysterectomy. The immunolabeling of myofibroblastic metaplasia (alpha smooth muscle actin [ASMA] and collagen I), differentiated smooth muscle mar...