Sentinel Lymph Node Biopsy in Melanoma

Overview / Definition Sentinel lymph node biopsy (SLNB) is a surgical procedure used to determine the presence of metastatic melanoma in the first lymph node(s) that drains the tumor site, known as the sentinel lymph nodes (SLNs). By identifying and examining these nodes, clinicians can assess the spread of melanoma and make informed decisions regarding treatment. Epidemiology Melanoma is one of the fastest-growing cancers worldwide, with increasing incidence rates, particularly among young adults. The following points highlight the epidemiological aspects of melanoma and SLNB: Incidence: Melanoma accounts for approximately 1% of all skin cancers but is responsible for the majority of skin cancer deaths. Age: The peak incidence occurs between the ages of 25-29 in women and 30-34 in men. Risk Factors: Major risk factors include fair skin, light hair, excessive sun exposure, and a family history of melanoma. Pathophysiology / Mechanism The pathophysiology of melanoma involves the malignant transformation of melanocytes, which can then invade local tissues and metastasize to lymph nodes and distant sites. The mechanism behind SLNB is based on the concept of lymphatic drainage: Lymphatic Mapping: Lymphatic mapping identifies the SLNs using a radiotracer and/or blue dye injected near the tumor. Metastatic Spread: If melanoma cells are present in the SLN, it indicates a higher likelihood of systemic spread. Clinical Presentation Patients with melanoma may present with various signs and symptoms depending on the stage of the disease. The typical clinical presentation includes: Skin Lesions: Asymmetrical, irregularly bordered moles with varied color and diameter greater than 6 mm. Lymphadenopathy: Enlargement of regional lymph nodes may indicate metastasis. Systemic Symptoms: Advanced melanoma may present with fatigue, weight loss, and other systemic symptoms. Diagnosis / Workup The diagnosis of melanoma is initiated through a thorough clinical examination, followed by imag