Detection and credibility of sentinel node in vulvar cancer: a single institutional study and short review of literature

Abstract

Purpose: To evaluate the detectability and credibility of sentinel lymph node (SLN) in vulvar cancer.

Methods: With Tc99m-nanocolloid and methylene blue, we identified SLNs in 34 patients. In 27 cases both tracers were used, while in 7 only blue dye was used. Completion lymphadenectomy was performed in all patients. SLNs and non-SLNs were sent separately for pathologic evaluation.

Results: At least one SLN was identified in all patients. Detection rate per groin was not significantly higher in the combined versus blue dye only technique (42/50 vs. 10/14, p = 0.43). 99m-Tc was not superior to blue dye in detecting SLN (42/50 vs. 50/64, p = 0.65). Midline location of the tumor did not seem to negatively affect the procedure. Four false negatives were observed in three patients with tumors >4 cm. Negative predictive value of SLN was 100% for grade I tumors ≤ 4 cm in patients ≤ 71 years.

Conclusion: Tc-99m does not seem to be superior to methylene blue in the detection of SLN in vulvar cancer. Patients of younger age with small, well-differentiated tumors appear to be the most suitable candidates for lymphatic mapping.