• Adrenal hyperplasia:
  • Secondary to excessive pituitary ACTH production
    • Pituitary-hypothalamic dysfunction
    • Pituitary ACTH-producing micro-or macroadenomas
  • Secondary to ACTH or CRH producing nonendocrine tumors
    1. bronchogenic carcinoma
    2. thymic carcinoma
    3. pancreatic carcinoma
    4. bronchial adenoma
• Adrenal nodular hyperplasia
• Adrenal neoplasia
  • Adenoma
  • Carcinoma
• Exogenous, iatrogenic causes (most common cause)
  • long-term glucocorticoid use
  • long-term ACTH use
  • Primary Non-iatrogenic Cause:
    •  bilateral adrenal hyperplasia due to pituitary adenoma (basophilic tumor)
    •  about 20 to 25 percent of Cushing's syndrome patients have adrenal neoplasm

"Adenoma composed of basophilic cells (blue with H&E stain) in Cushing disease."

• Ó 1999 KUMC Pathology and the University of Kansas, used with permission; courtesy of Dr. James Fishback, Department of Pathology, University of Kansas Medical Center.

Primary aldosteronism 

• Overview:
  •   twice as common in women as in man
  •     most often presents between 30 in 50 years of age

• Most common cause:
  • Adrenal adenoma -- excessive aldosterone production
    • unilateral adenoma (usually small; either side)
  • Conn's syndrome
• Other causes:
  • hyperplastic adrenal glands -- abnormal secretion
  • malignant tumor
    • adrenal carcinoma (rare)
• Physiological Effects of aldosterone hypersecretion:
  • increased renal distal tubule or exchange of sodium for secreted potassium and hydrogen ions -- body potassium depletion/hypokalemia
• Diagnosis--Criteria:
  1.   diastolic hypertension (no edema)
  2.   renin hyposecretion (low plasma renin activity)
     • renin secretion does not increase with volume depletion
  3.   aldosterone hypersecretion that is not suppressed with volume expansion

Secondary aldosteronism 

• Cause: inappropriate increased aldosterone production due to renin-angiotensin system activation
•   Associated with:
  •   Accelerated hypertension
  •    Edema 
• in pregnancy:
  • normal physiologic response to estrogen-induced increased plasma renin substrate and plasma renin activity and to antialdosterone actions of progestogens
• in hypertension -- cause:
  • over production of renin (primary reninism)
  •  renin over production secondary to reduced renal blood flow/perfusion pressure
    •   reduced renal artery lumen secondary to atherosclerosis or fiber muscular hyperplasia
  •   severe arteriolar nephrosclerosis (malignant hypertension)
  •   profound renal vasoconstriction (accelerated hypertension)

• ßmay be caused by rare renin-producing tumors (primary reninism)
  • juxtaglomerular cell tumor
• Physiological characteristics:
  • increased plasma renin activity
  • moderate/marked increases in aldosterone levels
  • hypokalemic alkalosis

• Pheochromocytoma 
  • Occurs as:
    •  a singular tumor or as
    •  an element of  multiple endocrine neoplasia {including thyroidal medullary carcinoma and hyperparathyroidism}
  • Associated with elevated catecholamine levels
  • Surgical manipulation {during tumor removal} is likely to cause a rapid increase in blood-pressure due to releases of catecholamines.
  • Patients with pheochromocytoma may have reduced blood volume-a factor to consider in perioperative management
  • Undiagnosed pheochromocytoma in patients presenting intraoperatively with hypertension is associated with high mortality {50%}
  • Pharmacological management prior to tumor removal
    •  a &ß-adrenoceptor blockers (a blockers to reduce vasoconstriction; ß-blockers decrease heart and contractility, also reducing blood pressure) -- both groups of adrenergic blocking agents protect against the effects of elevated circulating catecholamines due to tumor.
      • a-adrenergic blockade should precede beta-receptor blockade in order to prevent severe hypertension due to unopposed (ß-receptor-mediated) a receptor mediated  vasoconstriction.
      • a-adrenergic blockers--Phenoxybenzamine (Dibenzyline) or phentolamine (Regitine): used to control blood pressure prior to definitive surgical treatment