Final answer:
A melanoma is a cancerous growth composed of melanocytes that often arises in preexisting moles. Melanomas are highly metastatic and difficult to detect before spreading to other organs. Treatment typically involves surgical excision and immunotherapy.
Step-by-step explanation:
A melanoma is a cancerous growth composed of melanocytes, which are the pigment-producing cells in the epidermis of the skin. Melanomas often arise in preexisting moles. They are the most fatal type of skin cancer, as they can spread to other organs and are difficult to detect early.
Some common characteristics of melanomas include asymmetrical brown or black patches with uneven borders and a raised surface. Treatment for melanoma usually involves surgical excision to remove the tumor and may also include immunotherapy.