Question
Most common cause of hypercalcemic crisis is –
| A. |
Parathyroid adenoma |
| B. |
Parathyroid hyperplasia |
| C. |
Carcinoma breast |
| D. |
Paget’s disease |
Show Answer
|
Correct Answer » A Explanation |
 |
A hypercalcemic crisis is a life-threatening medical emergency characterized by:
- Severe hypercalcemia (usually serum calcium >14 mg/dL)
- Dehydration
- Altered sensorium
- Cardiac arrhythmias
- Acute kidney injury
The two major causes are:
- Primary hyperparathyroidism
- Malignancy-associated hypercalcemia
Why Option A is Correct
Parathyroid adenoma is the most common cause of primary hyperparathyroidism, accounting for approximately 80–85% of cases.
Primary hyperparathyroidism is the most common cause of hypercalcemic crisis in surgical and endocrine MCQs.
Mechanism:
- Excess Parathyroid Hormone (PTH)
- Increased bone resorption
- Increased renal calcium reabsorption
- Increased intestinal calcium absorption (via Vitamin D activation)
Why Other Options are Incorrect
B. Parathyroid Hyperplasia
- Causes primary hyperparathyroidism.
- Accounts for approximately 10–15% of cases.
- Less common than parathyroid adenoma.
C. Carcinoma of the Breast
- Can cause hypercalcemia through:
- Osteolytic bone metastases
- PTH-related peptide (PTHrP)
- Malignancy is a common cause of severe hypercalcemia, but among the options, parathyroid adenoma remains the most common cause of hypercalcemic crisis in standard surgical/endocrine examinations.
D. Paget’s Disease
- Usually does not cause significant hypercalcemia.
- Hypercalcemia may rarely occur during prolonged immobilization.