[Metastatic Squamous Cell Carcinoma with Unknown Primary Origin in the Mediastinal Lymph Node].

We report a case of a patient with squamous cell carcinoma metastasis confined to a mediastinal lymph node, with no identifiable primary tumor. The patient remains cancer-free 2 years after diagnosis. Although various theories exist regarding the etiology of lymph node carcinoma of unknown primary origin, advances in elucidating its pathogenesis and integrating treatment strategies based on genetic profiling are expected to form the foundation of future clinical practice.