Utility of Intraoperative Frozen Section of the Inguinofemoral Sentinel Lymph Node in Vulvar Cancer: A Retrospective Cohort

Objective: Sentinel lymph node dissection (SLND) spares most patients diagnosed with clinically early-stage vulvar cancer from undergoing complete inguinofemoral lymphadenectomy (IFLND). We sought to evaluate the intraoperative examination of frozen sentinel lymph node (SLN) sections to assess the need for IFLND. Methods: We identified patients with vulvar cancer treated at a tertiary referral center between January 2006 and December 2019 who either underwent SLND or met the eligibility criteria to receive SLND. All patients were restaged according to the International Federation of Gynaecology and Obstetrics (FIGO) 2009 guidelines. The records of each patient were reviewed for disease characteristics, follow-up status, patient demographics, SLN eligibility, and surgical and pathologic variables. Results: Of 142 eligible patients, 76 underwent SLND (53.5%) for a total of 118 groins assessed. We found no statistically significant differences in characteristics between the cohorts that received or lacked SLN examination. The SLN was detected in 90.8% (95% Confidence Interval (CI): 81.9%-96.2%) of patients. SLNs of 52 patients were sent for frozen section, and the results were used to direct further surgical intervention. The results of the frozen section pathology and the final pathology report exhibited a high degree of correlation per patient (100%) and per groin (98.7%). The 1 incorrect groin was negative on frozen but positive on final pathology and therefore no patients received an incorrect complete groin dissection. We observed no statistically significant differences in recurrence-free survival or overall survival rates between those patients who received or did not receive SLND. Conclusions: The use of intraoperative frozen section is appropriate for assessing node status at time of initial surgery. The use of this method decreases the incidence of reoperation by identifying those patients who warrant immediate IFLND.