Sentinel node dissection and ultrastaging in squamous cell cancer of the vulva

Objective. The aim of this study was to evaluate the findings when patholog ic ultrastaging techniques are applied in conjunction with sentinel node di ssection in patients with vulvar cancer. Methods. Patients with squamous cell cancer of the vulva underwent intraope rative lymphoscintigraphy following intradermal injection of 99mTc-labeled sulfur colloid at the site of the primary tumor. Isosulfan blue dye was als o injected at the tumor site to facilitate identification of the sentinel n ode in the groin. Following removal, the sentinel node was then bisected an d examined in the standard manner using hematoxylin and eosin staining. Neg ative nodes were subjected to additional ultrastaging evaluation with seria l sectioning and immunohistochemical staining. Results. Nine patients with 10 primary tumors underwent radical local excis ion of the primary tumor and sentinel node dissection of the groin. Sentine l nodes were identified and removed in all patients. One node was positive by conventional staining; the remainder were all negative. Of these negativ e nodes, 2 were found to be positive for micrometastases on serial sectioni ng and immunohistochemical staining. Therefore 2 of 3 positive nodes were n ot detected using conventional histologic techniques. Conclusion. Sentinel node dissection appears to be technically feasible in patients with vulvar cancer. Pathologic ultrastaging combined with sentinel node dissection appears to be highly sensitive for detecting subclinical m icrometastases in the regional lymphatics. This technique potentially provi des a more accurate assessment with less surgical morbidity than convention al inguinal femoral lymphadenectomy. (C) 2000 Academic Press.