The Department of Defense is headed by a civilian; the Secretary of Defense, who is appointed by the President of the United States. Under the Secretary of Defense, there are three military departments: The Department of the Army, the Department of the Air Force, and the Department of the Navy. 1  Each of these military departments are also headed up by civilians; the Secretary of the Army, the Secretary of the Air Force, and the Secretary of the Navy.
Melanoma is not as common as other types of skin cancer, but it's the most serious and potentially deadly. Possible signs of melanoma include a change in the appearance of a mole or pigmented area.
What is skin cancer? Skin cancer is a broad term that refers to any type of cancer that begins in the cells of the skin. These cancers usually develop in the top layer of skin, also known as the epidermis. The most common types of skin cancer are basal cell carcinoma, squamous cell carcinoma and melanoma. In addition, there are several types of skin cancers that occur much less frequently, including kaposi sarcoma, merkel cell carcinoma, cutaneous (skin) lymphoma, skin adnexal tumors and various types of sarcomas.