Metastasis to the popliteal lymph nodes in lower extremity melanoma and their management

How to do it: popliteal lymph node dissection

Popliteal lymph node metastasis is not very frequent. However, in case of lymph node metastasis in the popliteal fossa, template lymph node dissection needs to be performed. In view of the rarity of this procedure, we aim to describe the stepwise technique of popliteal lymph node dissection.

Popliteal lymph node dissection for metastases of cutaneous malignant melanoma

Popliteal lymph node dissection is performed when grossly metastatic nodal disease is encountered in the popliteal fossa or after microscopic metastasis is found in interval sentinel nodes during clinical staging of cutaneous malignant melanoma. Initially, an S-shaped incision is made to gain access to the popliteal fossa. A careful en bloc removal of fat tissue and lymph nodes is made to preserve and avoid the injury of peroneal and tibial nerves as well as popliteal vessels, following the previous recommendations. This rare surgical procedure was successfully employed in a patient with cutaneous malignant melanoma and nodal metastases at the popliteal fossa. The technique described by Karakousis was reproduced in a step-by-step fashion to allow anatomical identification of the neurovascular structures and radical resection with no post-operative morbidity and prompt recovery. Popliteal lymph node dissection is a rarely performed operative procedure. Following a lymphoscintigraphic examination of the popliteal nodal station, surgeons can be asked to explore the popliteal fossa. Detailed familiarity of the operative procedure is necessary, however, to avoid complications.

Long-term treatment outcome after only popliteal lymph node dissection for nodal metastasis in malignant melanoma of the heel: the only "interval node" dissection can be an adequate surgical treatment

We present a patient with malignant melanoma on his heel. Wide local excision was performed, along with sentinel lymph node biopsy of the inguinal and popliteal lesions. The primary site was clear of tumor at all margins; the inguinal nodes were negative, but the popliteal node was positive for metastatic melanoma. Only radical popliteal lymph node dissection was performed. The patient went on to receive adjuvant chemoimmunotherapy. There was no recurrence or complication until the long-term followup. Popliteal drainage from below the knee is uncommon, and the rate of popliteal-positive and inguinal-negative cases is estimated to be less than 1% of all melanomas. There is no established evidence about how to treat lymph nodes in these cases. Because we considered popliteal nodes as a regional, not interval, lymph node basin, only popliteal lymph node dissection was performed, and good postoperative course was achieved. The first site of drainage is the sentinel node, and the popliteal node can be a sentinel node. The inguinal node is not a sentinel node in all lower extremity melanomas. This case illustrates the importance of individual detailed investigation of lymphatic drainage patterns from foot to inguinal and popliteal nodes.