Beyond anatomy: deciphering metastasis to enhance diagnosis and treatment in head and neck carcinoma of unknown primary.

Head and Neck Carcinoma of Unknown Primary (HNCUP) denotes a condition where histologically confirmed cervical metastatic cancer lacks a discernible primary tumor site despite exhaustive evaluation. Patients typically present with incidentally detected neck masses, often without overt symptoms or with mild discomfort, with squamous cell carcinoma as the predominant histotype. The intricate interplay of tumor biology, lymphatic drainage, and molecular pathology in HNCUP poses significant challenges to the identification of the primary lesion using conventional imaging and endoscopic modalities, thereby impeding clinical diagnosis and management. This review will examine the potential mechanisms of metastasis in HNCUP, the characteristics of cervical lymph node metastasis, and recent advancements in diagnostic and therapeutic strategies. By thoroughly analyzing lymph node metastasis patterns and potential mechanisms, and by integrating modern imaging techniques with molecular marker detection, we aim to enhance the recognition rate of primary lesions and lay the groundwork for personalized treatment.