The value of Cloquet's node in predicting melanoma nodal metastases in the pelvic lymph node basin.

BACKGROUND: A selection of melanoma patients with groin metastases can benefit from a pelvic (iliac/obturator) lymph node dissection in addition to the infrainguinal dissection. However, there are no reliable criteria to determine which patients may benefit from such an inguinal-pelvic lymphadenectomy.
METHODS: In 142 patients (group A) out of a review of 214 groin dissections performed between 1980 and 1994, the tumor status of Cloquet's node was traced retrospectively. In 52 additional patients (group B), the status of Cloquet's node was registered prospectively. The number of positive lymph nodes and the total numbers of retrieved nodes were recorded as well. All patients underwent a combined therapeutic inguinal-pelvic lymph node dissection between January 1995 and June 1999 in a tertiary referral center.
RESULTS: Cloquet's node was free of disease in 18 of 39 patients with involved pelvic nodes in the retrospective study (sensitivity, 54%; negative predictive value, 83%). In the prospective study, 9 of the 20 patients with involved pelvic nodes had a tumor-free Cloquet's node (sensitivity, 55%; negative predictive value, 78%). Additional immunohistochemical staining of Cloquet's node resulted in a sensitivity of 65%. In the combined group A&B, the number of positive nodes in the inguinal region (cutoff point more than three nodes) had a sensitivity of 41% and a negative predictive value of 78% to determine the pelvic nodal status. When we combined the number of positive inguinal nodes and Cloquet's node in group A&B, the best sensitivity was 56% and the best negative predictive value was 82%.
CONCLUSIONS: Cloquet's node has a low sensitivity to predict the pelvic nodal tumor status. This was barely improved when we accounted for the number of positive inguinal nodes. Groin lymph node dissections should encompass the iliac and obturator compartments in patients with palpable inguinal node metastases.