Malignant Melanoma with Simultaneous Inguinal and Popliteal Lymph Node Metastases: A Rare Case Report

Abstract

Metastatic malignant melanomas of the distal leg and the foot traditionally metastasize to the lymph nodes of the groin. Rarely, the first site of nodal metastasis can be the popliteal fossa. The rate of popliteal metastasis in lower extremity melanomas ranges from 0.3% to 7%. Simultaneous popliteal and inguinal lymph node metastases are also quite rare. We present a case of a melanoma located in the heel with palpable popliteal lymph node involvement but without evidence of inguinal lymph node involvement on clinical examination and PET imaging. However, the histopathological results revealed that the inguinal lymph nodes had been infiltrated with melanoma. This case report is presented to draw surgeons’ attention to lymph node metastases in both the inguinal and popliteal regions, even when neither clinical examination nor imaging reveals the inguinal metastasis.