High prevalence of atypical hyperplasia in the endometrium of patients with epithelial ovarian cancer.

OBJECTIVES: The aim of the present study is to determine the prevalence of endometrial premalignancies in women diagnosed with epithelial ovarian cancer (EOC).
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: Apart from synchronous endometrial carcinoma, endometrial premalignancies should be taken into account when determining optimal treatment for women diagnosed with EOC. Copyright© by the American Society for Clinical Pathology.