Adrenal Disorders: Cushing, Addison, Conn, and Pheochromocytoma

Cushing Syndrome and Cushing Disease

Cushing Syndrome is characterized by the production of excess cortisol, often resulting from glucocorticoid (GCD) medication. Cushing Disease specifically refers to a pituitary tumor causing the overproduction of ACTH.

Clinical Features

• Sudden weight gain and truncal obesity
• Buffalo hump and moon face
• Abdominal striae
• Red face (due to thinning blood vessels)
• Hypertension

Laboratory Findings

• Hypernatremia (High Na)
• Hypokalemia (Low K)
• Glucosuria

Diagnosis

1. Low-Dose Dexamethasone Suppression Test: In cases of pituitary adenoma, there will be a suppression of cortisol.
2. No Response to Dexamethasone: If cortisol remains high, it indicates an ACTH-secreting tumor or adrenal neoplasia.
3. Adrenal Neoplasia vs. ACTH-Secreting Tumor: Differentiated by ACTH levels (Normal/Low in adrenal neoplasia vs. High in ACTH-secreting tumors).

Treatment

• Surgical Resection: Primary treatment for tumors.
• Non-resectable Adrenal Tumors: Managed with Ketoconazole or Metyrapone.
• Cushing Disease (ACTH-secreting Adenoma): MRI followed by surgical resection.
• Ectopic ACTH-secreting Tumor: Chest CT to locate the neoplasm, treated with Ketoconazole or Metyrapone.

Addison Syndrome (Adrenal Insufficiency)

General Characteristics: Loss of cortisol (hypocortisolism) caused by autoimmune destruction or unknown factors. It can present as acute adrenal insufficiency.

Symptoms

• Salt craving and orthostatic hypotension
• Weakness and weight loss
• Increased skin pigmentation
• Amenorrhea
• Slightly lower blood pressure

Laboratory Findings

1. Hyponatremia and hyperkalemia
2. Metabolic acidosis (with normal renin levels)

Diagnosis

• Stabilizing the patient
• Cosyntropin stimulation test

Treatment

• Prevention: Focus on preventing adrenal crises.
• Replacement Therapy: Replace glucocorticoids (cortisol) and mineralocorticoids (aldosterone).
• Mineralocorticoid Replacement: Use Fludrocortisone.
• Illness Management: Increase prednisone dosage during illness.

Secondary Hyperaldosteronism

This condition is characterized by excess renin production.

Conn Syndrome (Primary Hyperaldosteronism)

General Characteristics: Excess secretion of aldosterone from the adrenal gland, usually caused by an adenoma in adults.

Symptoms

• Hypertension
• Weakness and fatigue
• Polyuria and polydipsia
• Headache
• Labs: Hypernatremia and hypokalemia

Diagnosis

• Aldosterone-to-Renin Ratio (ARR): An ARR > 23.6 indicates primary hyperaldosteronism.
• Abdominal CT scan.
• Laboratory confirmation of hypernatremia and hypokalemia.

Treatment

• Spironolactone (potassium-sparing diuretic)
• Adrenalectomy (surgical removal of the adrenal gland)

Pheochromocytoma

General Characteristics: An adrenal tumor of the chromaffin cells that secretes Epinephrine (E) and Norepinephrine (NE).

Symptoms

Diagnosis requires the presence of several of the following:

• Hypertension (HTN)
• Headache
• Perspiration
• Palpitations
• Pallor
• Tachycardia
• Flushing
• Panic attacks

Diagnosis

• Plasma metanephrine levels should be elevated; if not, the condition can be ruled out.

Treatment

• IV therapy for severe hypertension
• Alpha-blocker therapy (e.g., Phenoxybenzamine)
• Beta-blockers (only once blood pressure is stabilized)
• Surgical intervention