Sentinel lymph node detection and microstaging in vulvar carcinoma

OBJECTIVE: To determine the efficacy of using complementary techniques for detecting sentinel lymph nodes (SLNs) in vulvar carcinoma and to evaluate t he utility of microstaging techniques. STUDY DESIGN: Patients with invasive vulvar carcinoma underwent sentinel ly mph node detection (SLND) using preoperative lymphoscintigraphy, intraopera tive isosulfan blue dye injection and an intraoperative hand-held gamma-det ecting probe. Eleven patients were included and a total of 16 groins evalua ted. Sentinel nodes identified were excised, bisected and examined in surgi cal pathology using hematoxylin and eosin (H&E) staining. Pathologically ne gative SLNs were subjected to additional microstaging via serial sectioning and immunohistochemical staining for cytokeratin. Surgical management of t he vulvar cancer and extent of inguinal-femoral lymphadenectomy were indivi dualized based on clinico-pathologic parameters, including depth of invasio n, location of the tumor and patient performance status. RESULTS: Lymphoscintigraphy, dye and gamma-detector methods led to the tota l detection of 16, 19 and 17 SLNs, respectively. In two cases the isosulfan blue dye assisted in the isolation of an additional sentinel node over tha t of the gamma probe. Each method individually identified SLNs in 10/11 pat ients (91%). A total of 19 sentinel nodes were isolated. One SLN (5%) was p ositive for metastatic disease using H&E staining. Of the 18 negative SLNs, 2 (11 %) had micrometastases (< 0.2 mm) upon serial sectioning and immunoh istochemical staining. CONCLUSION: Combined-modality mapping enhances detection of SLNs in vulvar carcinoma. Histologic microstaging improves the detection of micrometastase s within SLNs.