PTH controls calcium and phosphorus levels in the blood. PTH is made by the parathyroid glands, which are four pea-sized glands that lie behind the thyroid gland. If the blood calcium level is too low, the parathyroid glands release more PTH.
Skin cancer is a cancer of the cells in the outermost layer of skin, called the epidermis. The epidermis itself has three layers: an upper and middle layer made up of squamous cells, and a bottom layer made up of melanocytes and basal cells.
Melanoma is a type of skin cancer, the other main types being basal cell carcinoma and squamous cell carcinoma. Melanoma is the most aggressive of the skin cancers. Melanoma is a cancer of skin cells called melanocytes, which produce the pigment in moles, freckles and tanned skin. Melanomas can occur anywhere on the skin, but are most common on the chest and back in men, and the legs in women. The head and neck are other common sites.