The aim of the present study is to determine the prevalence of endometrial premalignancies in women diagnosed with epithelial ovarian cancer (EOC).
Endometrial and ovarian specimens of 186 patients with EOC were retrospectively selected using the nationwide pathology network and registry, and sections were comprehensively reviewed: 136 (73%) serous, 19 (10%) endometrioid, 15 (8%) mucinous, seven (4%) clear cell, and nine (5%) undifferentiated. Immunohistochemical phenotypes were compared for patients with serous EOC with concurrent endometrial pathology.
In 31%, endometrial (pre)malignancy was found: carcinoma in 3%, endometrial intraepithelial carcinoma (EIC) in 4%, and atypical hyperplasia in 24%. Atypical hyperplasia was found in 47% of endometrioid EOCs but in 7% to 33% of other subtypes. Body mass index was higher concurrent to atypical hyperplasia (P=.001). Serous EOC and EIC immunophenotypes were comparable, whereas atypical hyperplasia was expressed differently.
Apart from synchronous endometrial carcinoma, endometrial premalignancies should be taken into account when determining optimal treatment for women diagnosed with EOC.