Patterns of inguinal groin metastases in squamous cell carcinoma of the vulva

Assess the pattern of groin node metastases in squamous cell carcinoma (SCC) of the vulva in relation to the site of the primary lesion. Assess whether the identified pattern of lymphatic spread supports the current surgical practice of assessing contralateral nodes for lateral lesions with ipsilateral nodal involvement.

A retrospective study of surgically staged patients with primary SCC of the vulva between 1955 and 1990 was conducted. This cohort of patients was divided in 4 subgroups by location of primary lesion: unilateral, bilateral, midline, and patients with mediolateral lesions. All clinical and pathological data were reviewed and updated to the 1988 TNM vulvar classification.

320 patients met the inclusion criteria, and almost all of them (>95%) underwent bilateral groin assessment. Of the 108 patients with positive groin lymph-node (LN) involvement, 77 presented with unilateral and 24 with bilateral inguinofemoral involvement. Of the 163 patients presenting with only unilateral vulvar lesions, 48 had inguinofemoral node involvement: 37 with ipsilateral-only nodal metastases, 8 with bilateral LN invasion, and only 3 (1.8%) had isolated contralateral nodal metastases. None of these patients with unilateral vulvar lesion that was either < or = 2 cm in biggest diameter or with invasion < or = 5 mm had bilateral groin LN involvement at diagnosis.

Ipsilateral lymphadenectomy is suitable for patients with unilateral lesions, distant from the midline, and either negative ipsilateral nodes, or with positive ipsilateral LN with lesions smaller than 2 cm.