Summary: Walthard cell nests, the Brenner tumor (benign, proliferating, low malignant potential, and malignant), and primary ovarian transitional cell carcinoma are considered to be primary female genital tract proliferations of transitional-type (urothelial) epithelium on conventional light microscopic grounds. In order to further investigate the similarities (or dissimilarities) of proliferations of female genital tract transitional epithelium and urothelium, we compared transitional cell proliferations (TCPs) of the female genital tract (n = 25) and urinary bladder (n = 15) using antibodies to carcinoembryonic antigen (CEA; clone 0062), carbohydrate determinant 19–9 (CA19–9; clone 1116-NS-19–9), cytokeratin 7 (CK-7; clone OV-TL 12/30), and cytokeratin 20 (CK-20; clone Ks 20.8), four monoclonal antibodies that have been shown to stain transitional cell urothelial proliferations. Both groups of tumors exhibited significant staining for CEA, CA19–9, and CK-7, and the difference in numbers of cases staining was not significant. CA19–9 was present in 15 of 25 female genital tract TCPs as compared with 12 of 15 bladder TCPs; CEA was present in 17 of 25 female genital tract TCPs and nine of 15 comparable bladder TCPs. CK-7 was present in all cases studied with the exception of one Walthard cell nest and a malignant Brenner tumor that was not immunoreactive with the other antibodies tested. In contrast, 13 of 15 bladder TCPs were CK-20 positive, whereas only one of 25 female genital tract TCPs was positive (<5% of cells). Walthard cell nests and benign Brenner tumors were more likely to be CA19–9 positive than were Brenner tumors of low malignant potential, malignant Brenner tumors, and primary transitional cell carcinoma of the ovary. We conclude that despite their apparent morphologic and immunologic similarity to TCPs of the urinary bladder (particularly at the histologically low-grade end of the transitional cell spectrum), Walthard cell nests and ovarian Brenner tumors constitute an immunophenotypically distinct form of TCP.
©1996International Society of Gynecological Pathologists