Introduction The aim of this study was to identify histological factors associated to lymph node metastasis (LNM) in vulvar cancer (VC).

Methods We retrospectively included 192 patients treated for VC at the Salah Azaiez Institute between 1994 and 2022. We analyzed the clinical and histological factors correlated with LN invasion.

Results The mean age was 64.93± 13.817 years (range, 24–104 years). Surgery consisted on a radical vulvectomy, hemivulvectoy, and pelvic exenteration in respectively 96.4%, 2.1%, and 1.6% of cases. Lymph node (LN) dissection was bilateral 88.5% of cases.The mean tumor size was 42.21± 24.018 mm. Tumors were classified as stage FIGO I, II, III and IV in 55.2%, 9.4%, 32.8% and 2.6% of cases. Perineural invasion (PNI) and lymphovascular space invasion (LVSI) were detected in 13.5 and 2.7% of cases.LNM was assessed in 67 patients (34.9%) with bilateral groin metastasis in 24 cases (35.8%). On univariate analysis, LN invasion was significantly correlated to the age < 70 years (41.8 vs 26.2% in patients aged more than 70 years, p=0.027), the presence of LVSI( 100% vs 39.8%, p=0.037) and PNI (80% vs 35.4%,p=0.001) and the tumor size exceeding 40 mm (45.8% vs 28.8%, p=0.017).On multivariate analysis, independent factors of LN metastasis were the presence of PNI (OR=0.298, 95%CI=0.174–0.686; p=0.001) and the tumor size (OR=0.199; 95%CI=0.021–0.379, p=0.029).

Conclusion/Implications Since LNM represent an independent prognostic factor for survival, a nomogram based on histological and clinical characteristics could lead to better detection of patients with a high risk of LN metastasis.