Ultramicro-trauma in the endometrial-myometrial junctional zone and pale cell migration in adenomyosis.

OBJECTIVE: To determine if ultrastructural tissue trauma occurs in the junctional zone in uteri in adenomyosis.

DESIGN: A case-control experimental study.

SETTING: Endometriosis research center.

PATIENT(S): Twelve uteri with adenomyosis, and 9 uteri without adenomyosis, were gained during laparoscopy-assisted vaginal hysterectomy.

INTERVENTION(S): Transmission electron microscopic study of the junctional zone, as well as immunohistochemical staining for epithelial cadherin, and van Gieson staining and immunofluorescence for CD45 and CD68.

MAIN OUTCOME MEASURE(S): Analysis of the electron microscopy photos and the immunoreactive scores of the staining.

RESULT(S): The inner myometrial muscle fibers were diversely arranged in adenomyosis; they were parallel to the basal endometrial glands in nonadenomyosis. Nuclear membrane infolding of the basal glandular epithelium and the disruption of the interface between basal endometrium and inner myometrium in adenomyosis (but not in nonadenomyosis) were evident. Intraepithelial pale cells were seen in the basal endometrial glands in both groups, but they lacked CD45 and CD68 expression. They were seen actively migrating into the stroma in adenomyosis only.

CONCLUSION(S): The myofiber disarray in the inner myometrium, and the nuclear membrane irregularities in adenomyosis, are evidence for ultramicro-trauma in adenomyosis. The migrating nonleukocytic pale cells may be involved in pathogenesis of adenomyosis.