Sentinel lymph node procedure is highly accurate in squamous cell carcinoma of the vulva

Purpose: To determine the diagnostic accuracy of the sentinel lymph node pr ocedure in patients with squamous cell carcinoma of the vulva and to invest igate whether step sectioning and immunohistochemistry of sentinel lymph no des increase the sensitivity for detection of metastases. Patients and Methods: Between July 1996 and July 1999, 59 patients with pri mary vulvar cancer were entered onto a two-center prospective study. All pa tients underwent sentinel lymph node procedure with the combined technique (preoperative lymphoscintigraphy with technetium-99m-labeled nanocolloid an d intraoperative blue dye). Radical excision of the primary tumor with uni- or bilateral inguinofemoral lymphadenectomy was performed subsequently. Se ntinel lymph nodes and lymphadenectomy specimens were sent for histopatholo gic examination separately, Sentinel lymph nodes, negative at the time of r outine pathologic examination, were re-examined with step sectioning and im munohistochemistry. Results: In 59 patients, 107 inguinofemoral lymphadenectomies were performe d (11 unilateral and 48 bilateral). All sentinel lymph nodes, as observed o n preoperative lymphoscintigram, were identified successfully intraoperativ ely. Routine histopathologic examination showed lymph node metastases in 27 groins, all of which were detected by the sentinel lymph node procedure, T he negative predictive value for a negative sentinel lymph node was 100% (9 7.5% confidence interval [CI], 95% to 100%), Step sectioning and immunohist ochemistry showed four additional metastases in 102 sentinel lymph nodes (4 %; 95% CI, 1% to 9%) that were negative at the time of routine histopatholo gic examination, Conclusion: Sentinel lymph node procedure with the combined technique is hi ghly accurate in predicting the inguinofemoral lymph node status in patient s with early-stage vulvar cancer. future trials should focus on the safe cl inical implementation of the sentinel lymph node procedure in these patient s, Step sectioning and immunohistochemistry slightly increase the sensitivi ty of detecting metastases in sentinel lymph nodes and should be included i n these trials. J Clin Oncol 18:2811-2816. (C) 2000 by American Society of Clinical Oncology.