Malignant Melanoma: Comprehensive Discussion Predisposing Factors Malignant melanoma arises from melanocytes, the pigment-producing cells in the skin. Several predisposing factors increase the risk of developing melanoma: 1. UV Exposure: Intense or intermittent exposure to UV radiation, primarily from sunlight or tanning beds. 2. Skin Type: Fair skin, light hair, and eyes (Fitzpatrick skin types I and II) have less natural protection against UV damage. 3. Family History: Genetic predisposition, including mutations in genes like CDKN2A (p16), CDK4, and MC1R. 4. Personal History: Previous melanoma or other skin cancers increase the risk of developing new melanomas. 5. Dysplastic Nevi: Atypical moles with irregular borders, variable color, and larger size. 6. Immunosuppression: Weakened immune system due to diseases like HIV/AIDS or immunosuppressive medications. 7. Xeroderma Pigmentosum: Genetic disorder impairing DNA repair mechanisms after UV exposure. Clinical Presentations of Melanoma Melanoma can present in various forms, often following the ABCDE rule for suspicious lesions: 1. 2. 3. 4. Asymmetry: One half of the mole does not match the other. Border: Irregular, scalloped, or poorly defined edges. Color: Varied shades of brown, black, tan, white, red, or blue within the same lesion. Diameter: Larger than 6 millimeters (about the size of a pencil eraser), although melanomas can be smaller. 5. Evolution: Changes in size, shape, color, or symptoms (itching, tenderness). Prognostic Variables Prognosis in melanoma is influenced by several factors, including: 1. Breslow Thickness: Depth of invasion of melanoma into the skin, measured in millimeters from the granular layer of the epidermis to the deepest point of invasion. 2. Clark's Level: Describes the depth of invasion anatomically into the layers of the skin (Level I to V), with higher levels indicating deeper invasion. 3. Ulceration: Presence of ulceration at the primary site correlates with poorer prognosis. 4. Mitotic Rate: Number of mitotic figures per square millimeter of invasive melanoma. 5. Lymphovascular Invasion: Spread of melanoma cells through lymphatic or blood vessels. 6. Satellitosis: Presence of satellite nodules of melanoma within 2 cm of the primary lesion. Sites for Metastasis and Staging Melanoma commonly metastasizes to: 1. Regional Lymph Nodes: Sentinel lymph nodes are the first draining lymph nodes at risk for metastasis. 2. Skin: In-transit metastases along lymphatic channels. 3. Lungs: Most common distant site. 4. Liver: Secondary common site. 5. Brain: Higher risk with advanced disease. Staging of Melanoma: • • TNM Classification: Tumor (size and thickness), Node (involvement of lymph nodes), Metastasis (spread to distant organs). Imaging: CT, MRI, or PET scans to detect regional and distant metastases.