Coexpression of cytokeratin and vimentin in eutopic endometrium and endometriosis throughout the menstrual cycle: evaluation by a computerized method.

OBJECTIVE: To evaluate quantitatively cytokeratin and vimentin staining in glandular and stromal cells of eutopic and ectopic endometrium. DESIGN: The investigation of cytokeratin and vimentin was carried out using the new computerized technology of image analysis. SETTING: University Hospital, Department of Gynecology. PATIENTS: Biopsies were taken from patients undergoing a laparoscopy for infertility (29 endometrial biopsies and 31 biopsies of peritoneal endometriosis). None of them were treated. RESULTS: Cyclic variations of cytokeratin and vimentin staining were noted in eutopic endometrium. The cytokeratin and vimentin staining pattern consistently was lower in ectopic endometrium than in eutopic endometrium. CONCLUSIONS: Endometriotic epithelial and stromal cells undergo a complex program of differentiation giving them histochemical characteristics similar to those observed in endometrium. Such a concomitant expression of antigenicity indicates their close relationship with their mesodermal müllerian origin.