A 17 year old female patient has hirsutism, hyperglycemia, obesity, muscle wasting, and increased circulating levels of ACTH. The most likely cause of her symptoms is:

This female patient's symptoms are classic for a primary elevation of ACTH (Cushing's Disease). Exogenous steroids would produce similar symptoms, except that circulating ACTH would be low because of negative feedback suppression at both hypothalamic (CRF) and anterior pituitary levels (ACTH). Addison's Disease is caused by glucocoicoid deficiency, not excess. Hypophysectomy would lead to a decrease in ACTH or remove the source of it.