A 50-year-old woman presents to the clinic with complaints of persistent fatigue, muscle weakness, and frequent headaches. She also mentions that she has been experiencing excessive thirst and frequent urination. On physical examination, her blood pressure is significantly elevated at 160/100 mmHg. Laboratory tests reveal hypokalemia and metabolic alkalosis. Further hormonal evaluation shows elevated aldosterone levels with suppressed plasma renin activity. An abdominal CT scan is ordered, which reveals a small mass in one of the adrenal glands. The endocrinologist suspects Conn’s syndrome and discusses the likely cause with the patient.
The most common cause of Conn’s syndrome is:
A. Adrenal adenoma
B. Adrenal hyperplasia
C. Adrenal carcinoma
D. Liver failure
The correct answer is A. Adrenal adenoma.
Explanation:
Conn’s syndrome, also known as primary hyperaldosteronism, is characterized by excessive production of aldosterone from the adrenal glands, leading to hypertension, hypokalemia, and metabolic alkalosis. Here’s why adrenal adenoma is the most common cause:
Adrenal Adenoma (A):
– Adrenal adenoma, specifically an aldosterone-producing adenoma, is the most common cause of Conn’s syndrome.
– These benign tumors autonomously secrete aldosterone, leading to the characteristic clinical features of the syndrome.
– Diagnosis is typically confirmed with imaging studies such as CT or MRI, which can identify the presence of an adrenal mass.
Explanation of Other Options:
– Adrenal Hyperplasia (B): Bilateral adrenal hyperplasia is another cause of primary hyperaldosteronism, though it is less common than adrenal adenoma. It involves diffuse enlargement of both adrenal glands and can also result in excessive aldosterone production.
– Adrenal Carcinoma (C): Adrenal carcinoma can cause hyperaldosteronism, but it is a rare cause compared to adenoma and hyperplasia. Adrenal carcinomas are malignant tumors and often present with other symptoms and signs of malignancy.
– Liver Failure (D): Liver failure is not a cause of Conn’s syndrome. It can lead to secondary hyperaldosteronism due to fluid imbalances and secondary activation of the renin-angiotensin-aldosterone system, but it is not a primary cause of Conn’s syndrome.
In summary, adrenal adenoma is the most common cause of Conn’s syndrome, making A. Adrenal adenoma the correct answer.
Conn Syndrome: Key Points
1. Definition:
- Also known as primary hyperaldosteronism.
- Characterized by excessive production of aldosterone by adrenal glands.
2. Causes:
- Most common cause: Adrenal adenoma (benign tumor).
- Less common: Adrenal hyperplasia, Adrenal carcinoma.
3. Clinical Features:
- Hypertension resistant to usual treatment.
- Features of hypokalemia
- Muscle weakness, fatigue.
- Headaches.
- Mild pedal edema (swelling of feet and ankles).
- Absence of significant edema due to aldosterone escape mechanism
4. Diagnosis:
- Elevated aldosterone levels.
- Low renin activity.
- Imaging studies (CT/MRI) to detect adrenal adenoma.
5. Treatment:
- Medications: Spironolactone (mineralocorticoid receptor antagonist).
- Surgical removal of adrenal adenoma (adrenalectomy).
- Lifestyle modifications: Low-salt diet, weight management.
6. Prognosis:
- Early diagnosis and treatment is essential to prevent complications like cardiovascular disease and kidney damage.
- Multidisciplinary approach involving endocrinologists, nephrologists, and surgeons.
7. Follow-up:
- Regular monitoring of blood pressure, electrolytes, and aldosterone levels.
- Adjustments in treatment as needed to maintain optimal control of hypertension and potassium levels.
- Patient education on the importance of medication adherence and lifestyle modifications for long-term management.