[1720] Immunohistochemistry Improves the Diagnostic Accuracy of Intrauterine Gestation in the Examination of Products of Conception

SM Bakhiet, J Fahy, JF Gillan. Rotunda Hospital/TCD, Dublin, Ireland

Background: The detection of chorionic villi in products of conception is crucial for diagnosing intrauterine gestation. In the absence of villi, intrauterine implantation can be diagnosed, by the presence of intermediate trophoblast. Gursan et al (2002) introduced anti-Cytokeratin as a marker for intermediate trophoblasts in such cases. The use of a panel of immunostains has not been widely studied. In addition, the role of deeper levels has not however been previously described in the literature as an alternative method for detecting chorionic villi.
Design: To further characterize the immunocytochemical features of intermediate trophoblast and to possibly identify a more sensitive marker, a conventional H&E deeper level in addition to a panel immunostains for AE 1/3, hPL and hCG were performed in 81 endometrial specimens from patients with first trimesteric miscarriage (suspected intra-uterine gestations) that lacked chorionic elements (Goup1). Endometrial specimens from 5 patients with known intrauterine gestation (Group 2), 5 patients with known Ectopic pregnancy (Group 3) and 5 patients with non-pregnant status (Group 4) were used as positive and negative controls respectively.
Results: Of 81 specimens of product of conception examined, all specimens did not show any chorionic villi on original histological examination however microscopic examination of deeper levels from these specimen showed 10/81 (12.35%) of cases having chorionic villi that didn't appear on the original H&E slides. Intermediate trophoblast in vessels and/or decidua was difficult to recognized by conventional light microscopy in all the test cases however it was identified by immunoperoxidase reactions for keratin in 44/81 (54.32%), hPL in 21/81 (25.93%) and hCG in 16/81 (19.75%) of these cases. Controls:- Group 2 showed 100 positivity, Group 3 and Group 4 were all negative. Cytokeratin AE 1/3 stained also the endometrial glands and occasional suspected single or clustered epithelial cells. This cross-reaction may potentially mislead the unwary. This was overcome with hPL/hCG stains, which proved negative in these settings.
Conclusions: This study reveals that combined Cytokeratin AE 1/3, hPL and hCG immunostains increases diagnostic yields. Cytokeratin is a very sensitive and reliable however we recommend using hPL and hCG in addition to Cytokeratin as markers to avoid false positive results.
Category: Techniques

Wednesday, March 11, 2009 1:00 PM

Poster Session VI # 243, Wednesday Afternoon