Lymph Node Metastases from Non-Melanoma Skin Cancer of the Head and Neck †

SIMPLE SUMMARY: Skin cancer, particularly non-melanoma skin cancer, is the most common malignancy in the world. There are both common and uncommon types that receive treatment every day. Despite their commonality, the management of each is not perfectly defined in the scientific literature. Many require surgical removal, but the management of regional metastasis (such as lymph nodes in the neck) may or may not require surgical removal, or even anything beyond observation. Further complicating matters, some may have microscopic regional metastases that cannot be detected with a physical exam or imaging. This article seeks to summarize the current literature on this topic and to offer specific insight on how to manage non-melanoma skin cancer that has migrated away from the primary site to the regional lymph nodes. ABSTRACT: Non-melanoma skin cancer (NMSC) represents the most common malignancy in the world, comprising exceedingly common lesions such as basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) and rare lesions such as Merkel cell carcinoma. Risk factors are widely recognized and include ultraviolet (UV) light exposure, radiation exposure, immunosuppression, and many others. As a whole, survival and functional outcomes are favorable, but each histopathological subtype of NMSC behaves differently. Treatment regimens for the primary site usually include wide surgical excision and neck dissection in cases of clinically involved metastatic lymph nodes. The elective management of draining nodal basins, however, is a contested topic. Nearly all subtypes, excluding BCC, have a significant risk of lymphatic metastases, and have been studied with regard to sentinel lymph node biopsy (SLNB) and elective neck dissection. To date, no studies have definitively established a true single standard of care, as exists for melanoma, for any of the NMSCs. As a result, the authors have sought to summarize the current literature and identify indications and management options for the management of the cervical lymphatics for each major subtype of NMSC. Further research remains critically necessary in order to develop complete treatment algorithms.