Routine SLN Biopsy for Endometrial Intraepithelial Neoplasia: A Pragmatic Approach or Over-Treatment?

Complex atypical hyperplasia, also known as endometrial intraepithelial neoplasia (EIN), is a precursor lesion to endometrial carcinoma and may also be conceptualized as a “stage 0” or carcinoma in situ of the endometrium. The diagnosis of EIN on endometrial biopsy or D&C is limited by a low sensitivity and negative predictive value (30–40% rate of coexisting invasive carcinoma on final hysterectomy specimen) creating a predicament for surgical planning [1]. Hysterectomy with lymph node assessment is the standard of care in endometrial carcinoma and, for that disease, sentinel lymph node (SLN) biopsy is now the preferred strategy for surgical staging preserving diagnostic information with high feasibility and low morbidity [2,3].