Hypofunction of the adrenal cortex, or Addison disease, is usually caused by autoimmune destruction of the gland. It may also result from a deficiency of ACTH from the pituitary. The lack of aldosterone results in water loss, low blood pressure, and electrolyte imbalance. There is also weakness, nausea, and increase of brown pigmentation. This last symptom is caused by release of a hormone from the pituitary that stimulates the pigment cells (melanocytes) in the skin. Once diagnosed, Addison disease is treated with replacement cortical hormones.
An excess of adrenal cortical hormones results in Cushing syndrome. Patients have a moon-shaped face, obesity localized in the torso, weakness, excess hair growth (hirsutism), and fluid retention (Fig. 16-7). The
FIGURE 16-7. Cushing syndrome. The woman has a moon face, buffalo hump, increased facial hair, and thinning of the scalp hair. (Reprinted with permission from Rubin E, Farber JL. Pathology. 3rd Ed. Philadelphia: Lippincott Williams & Wilkins, 1999.)
most common cause of Cushing syndrome is the therapeutic administration of steroid hormones. It also may be caused by a tumor. If the disorder is caused by a pituitary tumor that increases production of ACTH, it is referred to as Cushing disease.
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