Immunohistochemical analysis of estrogen and progesterone receptors in fallopian tubes during ectopic pregnancy.

OBJECTIVE: To study decidualization, estrogen receptor (ER), and progesterone receptor (PR) expression in fallopian tubes containing an ectopic pregnancy (EP).

DESIGN: Assessment of decidual reaction by light microscopy, staining of ER and PR in epithelium and stroma by immunohistochemical methods.

SETTING: Academic hospital.

PATIENTS: Twelve women with an ampullary located EP.

INTERVENTION: A partial or complete tubal resection.

RESULTS: Only minimal decidualization was observed in five tubes. Estrogen receptor expression was noted in glandular cells in seven tubes. No correlation was found between decidualization and ER staining. No PR expression was seen in glandular epithelium or in stroma.

CONCLUSIONS: It is postulated that absence of PR is correlated to poor decidualization and to failure of treatment of EP with antiprogestins (RU486).