Given that there is a significant prevalence of Lynch syndrome among patients with endometrial cancer (about 5% of patients with endometrial cancer), and given there is a known risk of endometrial cancer among patients with endometrial hyperplasia (40% risk of pre-existing occult cancer with endometrial intraepithelial neoplasia), it is hypothesized that a diagnosis of endometrial hyperplasia may herald on-going risk of harboring a Lynch Syndrome gene mutation.

The purpose of this study is to examine endometrial hyperplasia specimens and compare the frequency of Lynch Syndrome gene mutations between endometrial hyperplasia and endometrial cancer subjects. This will provide a rationale and opportunity for earlier screening, and reduce colon cancer morbidity and mortality secondary to the Lynch syndrome gene.

This is an observational cohort study. Tissue specimens obtained that have been labeled with the diagnosis of endometrial hyperplasia will be identified and their chart reviewed for demographic date of age, race, body mass index, and co-morbidities. The specimen will then be tested via immunohistochemistry for the mismatch repair proteins MLH1, PMS2, MSH2, or MSH 6. Their absence is indicative of Lynch Syndrome. Statistical analysis will then be performed to compare the incidence of Lynch syndrome in endometrial hyperplasia with Lynch Syndrome in endometrial cancer.

Inclusion Criteria:

• Appropriate specimen, hysterectomy or biopsy with final labeled diagnosis of endometrial hyperplasia of any grade

Exclusion Criteria:

• Any specimen that is later associated with endometrial cancer in subsequent pathology exam

Patients who underwent tissue sampling of any type and received a pathologic diagnosis of endometrial hyperplasia at WellSpan from 2014-2022.