Expression of PAX2 in papillary serous carcinoma of the ovary: immunohistochemical evidence of fallopian tube or secondary MÃ¼llerian system origin?
Cancer. 2007 Nov 15;110(10):2248-52. [Link]
Tong GX, Chiriboga L, Hamele-Bena D, Borczuk AC.
Department of Pathology, Columbia University Medical Center, New York, NY 10032, USA. firstname.lastname@example.org
PAX2 is a urogenital developmental transcription factor expressed in the Wolffian ducts, developing kidneys, and MÃ¼llerian ducts during embryonic stage. Its function in renal development is well documented and its clinical application in the diagnosis of lesions of renal origin has been reported recently. However, information on its role in the MÃ¼llerian-derived genital tract is sparse. In this study, we investigated the expression of PAX2 in human female genital tract using immunohistochemistry. We demonstrated that PAX2 was expressed specifically in the epithelial cells of fallopian tube, endometrial and endocervical glands, but not in the stromal tissues in these areas. PAX2 was detected in secondary MÃ¼llerian structures in the ovary, such as endometriotic and endosalpingiotic glands and rete ovarii, but not in ovarian surface epithelium, surface epithelium-derived inclusion cysts, stroma, or sex-cord-derived structures such as follicles, oocytes, and corpus luteum. In addition, PAX2 was detected in 67%
of ovarian papillary serous carcinomas (N=36) but rarely in peritoneal malignant mesotheliomas, with two exceptions (N=54). Interestingly, the two PAX2-positive ‘peritoneal malignant mesotheliomas’ were from female patients and were positive for estrogen receptor. The significance of expression of PAX2 and estrogen receptor in these cases is under investigation. Taken together, we suggest that PAX2 is a novel MÃ¼llerian-specific epithelial marker when used in proper clinical settings. Identification of PAX2 in the majority of papillary serous carcinomas of the ovary but not in the ovarian surface epithelium or epithelium-derived inclusion cysts suggests that this malignant epithelial tumor may be directly derived from the primary or secondary MÃ¼llerian epithelium in or surrounding the ovary, rather than from the surface epithelium or its derivatives.
Keywords: PAX2, human MÃ¼llerian system, female genital tract, papillary serous carcinoma of the ovary, peritoneal malignant mesothelioma