To the Editor,

With a great deal of interest, we read the article entitled “Indocyanine green fluorescence imaging: an effective method to find inguinal sentinel lymph node in a case of vulvar carcinoma” by Wunster et al. (1). The authors present a case report of sentinel lymph node (SLN) identification in a patient with vulvar cancer using the combination of near-infrared range/indocyanine green (ICG) and technetium-99m (Tc-99m) techniques. The patient had stage Ia1 squamous verrucous cancer.

We would like to highlight a recently published study by Guijarro-Campillo et al. (2), comparing the ICG technique to the standard Tc-99m technique (dual-modality method). The study revealed an overall SLN detection rate of 85.3% for Tc-99m and 82.7% for ICG. In addition, the sensitivity and positive predictive value for ICG compared to Tc-99m were 91.08% and 94.8%, respectively. We congratulate the team of Wunster et al. (1) for presenting their video article. However, we would also like to draw attention to the fact that vulvar verrucous carcinoma is a rare variant of squamous cell cancer, with a controversial surgical approach.

In a recent literature review by Zhang et al. (3), the authors demonstrated that although preoperative imaging could suggest suspicious inguinal lymph node metastasis, the role of lymph node assessment is controversial. Specifically, this literature review found that inguinal lymph node metastasis rarely occurs and was not identified in any of the 50 verrucous cancer patients in the literature, regardless of the approach (systematic inguinal lymphadenectomy or SLN protocol).

Once again, we congratulate the authors for their innovative technique.