Uterine rudiments in patients with Mayer-Rokitansky-Küster-Hauser syndrome consist of typical uterine tissue types with predominantly basalis-like endometrium.

OBJECTIVE: To analyze the histologic and immunohistochemical structure of uterine rudiments focusing on the endometrium in a representative group of patients with Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome compared with a control group.
DESIGN: Prospective comparative study.
SETTING: University hospital. PATIENT(S): Forty-two patients with MRKH syndrome and 13 control subjects. INTERVENTION(S): Representative biopsies or whole uterine rudiments were removed during surgery and processed by a standardized procedure including immunohistochemical staining and analysis. MAIN OUTCOME MEASURE(S): Histologic structure, tissue types, hormone receptor expression, endometrial proliferative capacity, and type in correlation with cycle phase. RESULT(S): Twenty-two of the uterine rudiments showed a duct-like structure or small cavity, 17 of which contained endometrial epithelium and CD10-positive stroma. All rudiments contained an intact myometrial layer. Tubal epithelium and stroma were found in three rudiment samples. No significant differences were observed with regard to estrogen receptor (ER) or progesterone receptor (PR) expression in endometrium or myometrium. Interestingly, patients showed predominantly basalis-like endometrium with specific lack of CD90 expression and significantly lower proliferation compared with controls. CONCLUSION(S): All typical uterine tissues can be found in uterine rudiments of patients with MRKH syndrome. Expression of hormonal receptors in the latter and controls did not differ significantly. Endometrium shows predominantly basalis-like features in uterine rudiments.