Results of ilioinguinal dissection for stage II melanoma.

Eighty-two Stage II melanoma patients with inguinal lymph node metastases have undergone ilioinguinal node dissections at UCLA during the past 10 years. Twenty-four (29.3%) patients had involvement of both inguinal and iliac nodes, whereas 58 (70.7%) patients had only inguinal metastases. The frequency of iliac metastases did not relate to location, Clark's level or thickness of the primary tumor or interval from diagnosis of primary tumor to lymphadenectomy, but was related to the number of inguinal nodes involved with metastases, rising from 14.6% with one positive inguinal node to 50% with four or more inguinal node metastases. Twenty of 24 (83.3%) patients with inguinal and iliac node metastases developed recurrent disease, whereas 32/58 (55.2%) patients with only inguinal node metastases and no tumor in the iliac nodes recurred. The time to recurrence was much shorter if iliac nodes were diseased (median disease-free interval 5.8 months versus 25.6 months). Three of five patients with clinically negative but histologically positive inguinal and iliac nodes survived 5 years, while only 1/18 patients with clinically positive inguinal nodes and diseased iliac nodes lived 5 years. Those with clinically negative but histologically positive inguinal nodes and iliac metastases had recurrence and survival rates similar to those with clinically negative but histologically positive inguinal nodes and no iliac metastases. Ilioinguinal lymphadenectomy provides significant prognostic information for Stage II patients with inguinal metastases and may be therapeutic for those with iliac metastases. Therefore, ilioinguinal dissection is the operation of choice for melanoma patients with regional metastases to the inguinal area.