Research ArticlesPAX2 and PAX8 Reliably Distinguishes Ovarian Serous Tumors From Mucinous TumorsWang, Min MSc; Ma, Haifen MD; Pan, Yunbao PhD; Xiao, Weihua MD; Li, Junqiang MD; Yu, Jihong MD; He, Ji MDAuthor Information *Department of Pathology, Beilun People’s Hospital, Ningbo, Zhejiang †Breast Tumor Center, Sun Yat-Sen Memorial Hospital ‡Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, People’s Republic of China Supported by the Scientific and Technological Project of Zhejiang Province (2011KYB103) to H.M., the National Natural Science Foundation of China (81372816) to Y.P. M.W., H.M., and Y.P. conceived of the study, designed and performed the experiments, analyzed data, and drafted the manuscript. W.X., J.L., J.Y., and J.H. contributed reagents and performed experiments. All authors read and approved the final manuscript. H.M. and Y.P. contributed equally to this work and should be considered as co-corresponding authors. The authors declare no conflict of interest. Reprints: Yunbao Pan, PhD, Breast Tumor Center, Sun-Yat Sen Memorial Hospital, Sun-Yat Sen University, 107 Yanjiang West Road, Guangzhou 510120, People’s Republic of China (e-mail: [email protected]). Received November 14, 2013 Accepted January 23, 2014 Applied Immunohistochemistry & Molecular Morphology: April 2015 - Volume 23 - Issue 4 - p 280-287 doi: 10.1097/PAI.0000000000000065 Buy Metrics Abstract Ovarian cancer is the leading cause of cancer-related death in gynecologic malignancies and consists of different histologic types. Histopathologic examination and accurate subtype diagnosis has become increasingly important in guiding patient management and, as such, is the most important currently available ovarian carcinoma “biomarker.” In this study, we examined the expression of PAX2 and PAX8 by immunohistochemistry in 58 cases of ovarian serous tumors and 68 cases of ovarian mucinous tumors. The results demonstrated that PAX2 and PAX8 were detected in 100% (30/30) and 77% (23/30) of serous cystadenomas, 100% (16/16) and 94% (15/16) of borderline serous cystadenomas, and 100% (12/12) and 83% (10/12) of serous carcinomas, respectively. However, PAX2 and PAX8 were detected in only 0% (0/29) and 0% (0/29) of mucinous cystadenoma, 4% (1/24) and 4% (1/24) of borderline mucinous cystadenoma, and 0% (0/15) and 7% (1/15) of mucinous carcinoma, respectively. Further, there is a linear correlation between PAX2 and PAX8 (R2=0.745; P<0.0001). Overall, our data indicated that PAX2 correlated with PAX8, and these 2 proteins differentially expressed in ovarian serous tumors and ovarian mucinous tumors. Thus, PAX2 and PAX8 are useful biomarker in the differential diagnosis of ovarian serous and mucinous tumors. Copyright 2015 Wolters Kluwer Health, Inc. All rights reserved.