Groin recurrence in patients with vulvar cancer with negative nodes on superficial inguinal lymphadenectomy.

OBJECTIVE: The objective of this study was to investigate the cause of groin recurrence in patients with vulvar cancer who had negative nodes in their superficial inguinal lymphadenectomy (SIL) specimens. METHODS: The records of patients with vulvar cancer treated at M. D. Anderson Cancer Center between 1986 and 1997 were reviewed to identify patients with squamous histology, clinical and surgical stage I or II, depth of invasion greater than 1 mm, and primary treatment consisting of radical wide excision and SIL. One hundred four patients met these criteria. Among these, nine experienced recurrent disease that involved one or both of the groins. All of the original hematoxylin and eosin (H&E)-stained slides were reviewed by one pathologist (AM). Then, each paraffin block containing nodal tissue was recut at 40 microm intervals to obtain five sections for H&E staining and two unstained sections to be used for cytokeratin immunostaining if necessary. RESULTS: The median age at diagnosis and primary surgery was 65 years and the median depth of invasion was 4 mm. Seven patients underwent bilateral, and two underwent unilateral, groin dissections. The median number of lymph nodes removed per groin was seven. The median time to recurrence was 22 months. A total of 785 additional H&E-stained slides were prepared and examined at 100x and 400x magnification. No micrometastases were identified, and there were no other suspicious findings. Therefore, immunohistochemical staining was not performed. At recurrence, one patient had a biopsy only, and eight had attempted surgical resection. In two patients, tumor was identified in fibroadipose tissue only; no lymph nodes were identified. Among the other six patients, the median number of lymph nodes resected at the time of the recurrence was five (range 1 to 10). At last report, six patients had died and three were alive and free of disease. Median follow-up for survivors was 63 months (range 42 to 71). CONCLUSION: These data strongly suggest that groin relapse in patients with negative nodes on SIL is caused by metastatic disease in unresected inguinal nodes. SIL as performed on the patients in this study did not eliminate all sites of nodal metastasis.