Popliteal lymph node metastasis from primary cutaneous melanoma

Aims: To document the incidence of popliteal lymph node involvement by metastatic melanoma and to consider the implications of this information for clinical management. Methods: From the computerized database of the Sydney Melanoma Unit, all patients with primary melanomas located at or distal to the knee were identified and their records were examined. Experience with those patients who developed popliteal node metastases was then reviewed. Results: Thirteen of 4262 patients (0.31%) with primary melanomas of the distal lower limb developed popliteal node metastases. Six of the 13 patients had previous, synchronous or subsequent groin node metastases. Conclusions: Popliteal lymph node involvement by metastatic melanoma is a rare event. The study results suggest only two indications for full popliteal node clearance—either a histologically positive sentinel node in the popliteal fossa or clinical evidence of metastatic disease in a popliteal node.