A study on uterine lymphatic anatomy for standardization of pelvic sentinel lymph node detection in endometrial cancer Barbara Geppert, Céline Lönnerfors, Michele Bollino, Anastasija Arechvo, Jan Persson ⁎ Department of Obstetrics and Gynecology, Skane University Hospital, Lund University, Lund, Sweden HIGHLIGHTS • Two consistent pelvic uterine lymphatic drainage pathways exist. • The external/obturator nodes drain the upper, the presacral the lower paracervical pathway. • Ideally, at least one SLN should be identified in each pelvic pathway bilaterally. • Cervical injection results in a higher technical success rate than fundal injection. • Lymph node metastases were found in 8% of patients with low risk profile. abstract article info Article history: Received 21 December 2016 Received in revised form 6 February 2017 Accepted 8 February 2017 Available online xxxx Objective. To describe the anatomy of uterine lymphatic drainage following cervical or fundal tracer injection to enable standardization of a pelvic sentinel lymph node (SLN) concept in endometrial cancer (EC). Methods. A prospective consecutive study of women with EC was conducted. A fluorescent dye (Indocyanine green) was injected into the cervix (n = 60) or the uterine fundus (n = 30). A systematic trans- and retroperi- toneal mapping of uterine lymphatic drainage was performed. Positions of the pelvic SLNs, defined by afferent lymph vessels, and lymph node metastases were compared. Results. Two consistent lymphatic pathways with pelvic SLNs were identified irrespective of injection site; an upper paracervical pathway (UPP) with draining medial external and/or obturator lymph nodes and a lower paracervical pathway (LPP) with draining internal iliac and/or presacral lymph nodes. Bilateral display of at least one pelvic pathway following cervical and fundal injection occurred in 98% and 80% respectively (p = 0.005). Bilateral display of both pelvic pathways occurred in 30% and 20% respectively (p = 0.6) as the LPP was less often displayed. Nearly one third of the 19% node positive patients had metastases along the LPP. No false negative SLNs were identified. Conclusions. Based on uterine lymphatic anatomy a bilateral detection of at least one SLN in both the UPP and LPP should be aimed for. Absence of display of the LPP may warrant a full presacral lymphadenectomy. Although pelvic pathways and positions of SLNs are independent of the tracer injection site, cervical injection is preferable due to a higher technical success rate. © 2017 Published by Elsevier Inc. Keywords: Endometrial cancer Lymphatic metastases Lymphadenectomy Lymphatic system Anatomy Sentinel lymph node biopsy Indocyanine green 1. Introduction Endometrial cancer (EC) is the most common cancer of the female reproductive organs in developed countries with a lifetime risk of 2.8% [1]. The most significant prognostic factors besides stage are histological type and grade. The initial management in early stage EC is usually sur- gical and the extent of the surgical procedure is determined by a preop- erative risk assessment. In women with a high risk for lymph node metastases (LNM), a full pelvic and infrarenal paraaortic lymphadenec- tomy is recommended in addition to the hysterectomy and bilateral salpingooophorectomy [2,3]. A lymphadenectomy is associated with higher morbidity and it is still controversial whether it in addition to being a staging procedure for prognosis and choice of adjuvant treat- ment also has a curative intent [4–6]. LNM are detected in approximate- ly 20% of women who belong to the high-risk group and in 3–9% of women in the low risk group [7–9]. A sentinel node (SLN) concept in all women with EC would allow for detection of LNM beyond a de- creased morbidity in women regardless of preoperative risk factors and diminish erroneous preoperative subgrouping that may befall up to 15% of patients [10–13]. Lymphatic mapping including identification Gynecologic Oncology xxx (2017) xxx–xxx ⁎ Corresponding author at: Department of Obstetrics and Gynecology, Skane University Hospital, SE-221 85 Lund, Sweden. E-mail address: Jan.Persson@med.lu.se (J. Persson). YGYNO-976642; No. of pages: 6; 4C: http://dx.doi.org/10.1016/j.ygyno.2017.02.018 0090-8258/© 2017 Published by Elsevier Inc. Contents lists available at ScienceDirect Gynecologic Oncology journal homepage: www.elsevier.com/locate/ygyno Please cite this article as: B. Geppert, et al., A study on uterine lymphatic anatomy for standardization of pelvic sentinel lymph node detection in endometrial cancer, Gynecol Oncol (2017), http://dx.doi.org/10.1016/j.ygyno.2017.02.018