Introduction/Background Among the most common problems encountered in gynecological pathology is the distinction of primary endometrial and primary endocervical adenocarcinomas. Accurate diagnosis in this cases is important because this has significant management, staging and prognostic implications. In the distinction between endometrial and endocervical origin for an adenocarcinoma, a panel of immunohistochemical markers should be used, depending on the morphologic subtype and not just the site of origin. The aim of our study was to determine which are the most useful markers used for proper differentiation of endocervical and endometrial adenocarcinomas.

Methodology This retrospective study included 109 cases admitted in the Gynecological Department of Clinical Emergency Hospital Oradea, from January 2019 until December 2021. Fractioned uterine curettage was performed. Following histopathological evaluation, the diagnosis of either endocervical, either endometrial carcinoma was established. Immunostaining for p16, vimentin, p53, CEA, ER and PR was performed in all cases.

Results In the distinction between usual-type endocervical adenocarcinoma and low grade endometrioid-type endometrial adenocarcinoma the most useful markers were p16 and ER, PR. In the distinction between usual-type adenocarcinoma and high grade endometrial adenocarcinoma p53 was of value. Positive rates of CEA and p16 expression in cervical adenocarcinoma were significantly higher than those in adenocarcinoma of endometrium. The expression’s intensity of vimentin, ER and PR was positively correlated with endometrial adenocarcinoma. On the basic of immunohistochemistry, 71 cases (65.13%) should be categorized as endometrial and 38 cases (34.86%) as endocervical adenocarcinoma.

Conclusion The primary site of adenocarcinoma dictates treatment, depending on clinical stage. Generally, endometrial cancer is managed surgically with adjuvant therapy and in endocervical cancer, sometimes radiation therapy alone is used in select cases, or is followed by surgery. Immunohistochemical testing with multiple markers aids in diagnostic evaluation of adenocarcinomas of endocervix and endometrium and is recommended in tumors of uncertain origin.