Metastatic Head and Neck Non-Melanoma Skin Cancer: A Retrospective Analysis of Clinico-Pathologic Features and Reconstructive Approach

Background/Objectives: Non-melanoma skin cancer (NMSC) is the most common malignancy globally, with cutaneous squamous cell carcinoma (cSCC) posing a significant risk of regional metastasis, especially in high-risk anatomical areas such as the head and neck. While general risk factors for metastasis are well known, few studies have directly compared the clinical and pathological features of synchronous versus metachronous metastatic behavior. This study aimed to evaluate the clinicopathological characteristics and reconstructive implications associated with these two metastatic patterns in head and neck NMSC. Methods: We conducted a retrospective observational study of 46 patients with histologically confirmed metastatic NMSC of the head and neck, treated between January 2022 and May 2024 at a tertiary care center. Patients were stratified into synchronous or metachronous metastasis groups. Clinical data, histopathological features, metastatic sites, and surgical approaches were analyzed. Comparative statistics were applied using chi-square and t-tests, with significance set at p < 0.05. Results: Of the 46 patients, 50% had synchronous and 50% had metachronous metastases. The lower lip was the most common primary tumor site in both groups. Perineural and lymphovascular invasion were more frequent in synchronous metastases. Metachronous cases often required more complex reconstructive procedures, including free flap reconstructions and mandibular resections. Patients with metachronous metastases were significantly older (p = 0.024), and approximately one-third developed metastases more than four years after initial treatment. Conclusions: Head and neck NMSC, particularly involving the lower lip, may exhibit late-onset metastatic potential. Risk-adapted surveillance extending beyond current guidelines is warranted to improve long-term outcomes in high-risk patients.