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.
Skin Cancer Image Gallery. Skin cancer is by far the most common type of cancer. Nearly all skin cancers can be treated effectively if they are found early, so knowing what to look for is important. There are many types of skin cancer, each of which can look different on the skin. This picture gallery contains some examples of the more common types of skin cancer, as well as some other non-cancerous types of skin growths. But skin cancers can look different from these examples.