Natthaporn Laoharojvongsa M.D., Tawatchai Silapyodom M.D.
Department of Anatomical Pathology, Army Institute of Pathology, Bangkok, Th ailand
Objective: Endometrial and endocervical adenocarcinomas can seem histologically identical and it can be diffi cult to determine the primary site of origin based on morphology alone. As the distinction is signifi cant and cannot always be made on the basis of clinical findings, various immunohistochemical panels have been proposed to aid in determining site of origin. The distinction is clinically significant and important to be made preoperatively because surgical management and postoperative decisions about chemotherapy and radiation therapy are driven by site of origin.
Materials and Methods: This was a retrospective study, using paraffi n-embedded samples obtained from 37 patients with endometrial adenocarcinoma and endocervical adenocarcinoma, treated at Pramongkutklao Hospital between 2009 and 2015. Stains for vimentin, estrogen receptor (ER), progesterone receptor (PR), carcinoembryonic antigen (CEA) and p16, were performed on 37 paraffi n-embedded samples, which consisted of 21 endometrial carcinomas and 16 endocervical adenocarcinomas. The endometrial and endocervical carcinomas represented usual endometrioid type.
Results: Of all markers performed, the panel of fi ve markers model classifi ed 100% (21/21) of endometrial cases and 81.3% (13/16) endocervical cases correctly with an overall diagnostic accuracy of 91.9%
Conclusion: Univariate analysis showed that fi ve markers (vimentin, ER, PR, p16 and CEA) performed well in distinguishing between endocervical and endometrial origin. Multivariate analysis showed that ER, PR and p16 are suffi cient for predictors of site. However, special variants of carcinomas were not included in this study.