The uterine pathological features associated with sentinel lymph node metastasis in endometrial carcinomas

BACKGROUND: In recent years, sentinel lymph node excision and ultrastaging have been performed in endometrial carcinomas to obtain information about lymph node status, avoiding unnecessary complete pelvic and paraaortic lymphadenectomy. The purpose of this retrospective study was to provide a comprehensive evaluation of the pathological features of endometrial carcinomas and their significance in association with sentinel lymph node involvement. METHODS: Patients with endometrial carcinomas, preceded by sentinel lymph node mapping, were classified into Group-I and Group-II with negative and positive involvement, respectively. The pathological features, associated with sentinel lymph node involvement, were statistically analyzed, including determination of test performance parameters. RESULTS: Among 70 patients who had undergone hysterectomy and sentinel lymph node excision, 61 had carcinoma and 9 had atypical hyperplasia. There were 50 patients in Group-I and 10 in Group-II. In Group-II, the significant pathological features were: 1) lower uterine segment involvement (100%), 2) an average tumor size of ≥5 CM, 3) lymphovascular invasion (50%), 4) cervical stromal invasion (40%), and 5) depth of myometrial invasion of ≥50% (50%). The incidences of these pathological features were significantly less in Group-I. Statistical analyses singled out “lower uterine segment involvement” as the most important feature. CONCLUSIONS: We have identified five pathological features which are associated with sentinel lymph node involvement. Since lower uterine segment involvement has occurred in all cases of the Group-II cohort, we recommend FIGO and other organizations that determine staging rules should consider whether tumors that involve the lower uterine segment should be staged as higher than “1a”, if the findings in this small series are confirmed by other studies. The results of this study may guide pathologists and oncologists in the diagnostic and therapeutic approaches to management of endometrial carcinomas.