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

Abstract

Metastatic malignant melanomas of the distal leg and foot typically metastasize to the lymph nodes of the groin. In rare cases, the first site of nodal metastasis is 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, which was not evident on clinical examination and positron emission tomography imaging. Despite this lack of evidence, the histopathological results revealed that the inguinal lymph nodes were infiltrated with melanoma. This case report is presented to draw surgeons’ attention to the possibility of lymph node metastases in inguinal and popliteal regions even when neither clinical examination nor imaging reveals inguinal metastasis.

Keywords

• Malignant melanoma
• lymphatic metastasis
• positron emission tomography