Cushing disease

  • Definition
  • Alternative Names
    • Pituitary Cushing disease; ACTH-secreting adenoma

  • Causes
    • Cushing disease is caused by a tumor or excess growth (hyperplasia) of the pituitary gland. The pituitary gland is located just below the base of the brain. A type of pituitary tumor called an adenoma is the most common cause. An adenoma is almost always benign (not a cancer).

      With Cushing disease, the pituitary gland releases too much ACTH. ACTH stimulates production and release of cortisol, a stress hormone. Too much ACTH causes the adrenal glands to make too much cortisol.

      Cortisol is normally released during stressful situations. It controls the body's use of carbohydrates, fats, and proteins. It also helps reduce the immune system's response to swelling (inflammation).

  • Symptoms
    • Symptoms of Cushing disease include:

      • Upper body obesity (above the waist) and thin arms and legs
      • Round, red, full face (moon face)
      • Slow growth rate in children

      Skin changes that are often seen include:

      • Acne or skin infections
      • Purple marks (1/2 inch or 1 centimeter or more wide), called striae, on the skin of the abdomen, thighs, and breasts
      • Thin skin with easy bruising, most commonly on the arms and hands

      Muscle and bone changes include:

      • Backache, which occurs with routine activities
      • Bone pain or tenderness
      • Collection of fat between the shoulders (buffalo hump)
      • Weakening of the bones, which leads to rib and spine fractures
      • Weak muscles

      Women often have:

      • Excess hair growth on the face, neck, chest, abdomen, and thighs
      • Menstrual cycle that becomes irregular or stops

      Men may have:

      • Decreased or no desire for sex (low libido)
      • Impotence

      Other symptoms may include:

      • Mental changes, such as depression, anxiety, or changes in behavior
      • Fatigue
      • Headache
      • Increased thirst and urination
  • Exams and Tests
    • Tests are done to confirm there is too much cortisol in the body, then to determine the cause.

      These tests confirm too much cortisol:

      These tests determine the cause:

      • Blood ACTH level
      • Brain MRI
      • Corticotropin-releasing hormone test, which acts on the pituitary gland to cause the release of ACTH
      • Dexamethasone suppression test (high dose)
      • Inferior petrosal sinus sampling (IPSS) -- measures ACTH levels in the veins that drain the pituitary gland compared to the veins in the chest

      Other tests that may be done include any of the following:

  • Treatment
    • Treatment involves surgery to remove the pituitary tumor, if possible. After surgery, the pituitary gland may slowly start to work again and return to normal.

      During the recovery process from surgery, you may need cortisol replacement treatments because your normal pituitary needs time to start making ACTH again.

      Radiation treatment of the pituitary gland may also be used if the tumor is not completely removed.

      If the tumor does not respond to surgery or radiation, you may need medicines to stop your body from making cortisol.

      If these treatments are not successful, the adrenal glands may need to be removed to stop the high levels of cortisol from being produced. Removal of the adrenal glands can cause the pituitary tumor to get much bigger (Nelson syndrome).

  • Outlook (Prognosis)
    • Untreated, Cushing disease can cause severe illness, even death. Removal of the tumor may lead to full recovery, but the tumor can grow back.

  • Possible Complications
  • When to Contact a Medical Professional
    • Call your health care provider if you develop symptoms of Cushing disease.

      If you have had a pituitary tumor removed, call your provider if you have signs of complications, including signs that the tumor has returned.

  • References
    • Molitch M. Anterior pituitary. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 224.

      Stewart PM, Newell-Price JDC. The adrenal cortex. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 13th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 15.