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.
For example, a biopsy of a skin lesion may prove it to be benign or malignant, or evolving into a malignant lesion (called a premalignant lesion). Lesions can be defined according to the patterns they form. For example, a bull's-eye or target lesion is one that looks like the bull's eye on a target. (In an X-ray of the duodenum, a bull's-eye lesion can represent a tumor with an ulcer (crater) in the center.) A coin lesion is a round shadow resembling a coin on a chest X-ray. It, too, is usually due to a tumor.