Objective: The aim was to determine the feasibility of surgical identification and pathological ultrastaging of sentinel nodes (SNs) in vulvar carcinoma and to evaluate whether SN negativity rules out the possibility of metastasis in other nodes and can therefore avoid conventional lymphadenectomy.
Material and methods: In 26 patients with vulvar squamous cell carcinoma the SNs were detected using both peritumoral injection of (99m)Tc and blue dye (isosulfan or methylene) before the surgical procedure. Dissection of the SNs was followed by standard lymphadenectomy and vulvar exeresis. For pathological ultrastaging at least eight histological sections of every node separated 400 microm were evaluated using hematoxylin & eosin and immunostaining against cytokeratin.
Results: We identified the SNs in 25/26 patients (96%). In 19 patients (76%) the SN was unilateral and in 6 (24%) it was bilateral. A total of 46 SNs were isolated. Metastatic carcinoma was identified in 9 SNs from 8 patients (30.8%). Thirty-eight percent (3 of 8) patients with metastatic SNs presented micrometastasis detected only in ultrastaging. Seven (3.3%) of 239 nonsentinel nodes (non-SNs) showed metastasis. No metastatic implant was detected in non-SNs when SNs were negative in patients without clinical suspicious adenopathy (100% negative predictive value).
Conclusion: Inguinofemoral lymph nodes can be confidently avoided when sentinel node metastases are excluded by histological ultrastaging. This may reduce the surgical morbidity of conventional inguinofemoral lymphadenectomy, without worsening vulvar cancer prognosis.