Primary Hyperparathyroidism — MCQs
In hypoparathyroidism:
A patient presented with complaints of pain in the flank region with hematuria. On investigation, X-ray shows multiple calcification (stones) in both kidneys. What is the probable diagnosis?
What is the initial treatment of choice for managing secondary hyperparathyroidism in patients with renal osteodystrophy?
A 45-year-old man undergoes a parathyroidectomy given recurrent episodes of dehydration and kidney stones caused by hypercalcemia secondary to an elevated PTH level. He is recovering on the surgical floor on day 3. His temperature is 97.6°F (36.4°C), blood pressure is 122/81 mmHg, pulse is 84/min, respirations are 12/min, and oxygen saturation is 98% on room air. The patient is complaining of perioral numbness currently. What is the most appropriate management of this patient?
A patient develops recurrent hyperparathyroidism 2 years after initial parathyroidectomy and has experienced cardiovascular complications due to persistent hypercalcemia. What is the most appropriate management?
What is the most common cause of hypercalcemic crisis?
What is the investigation of choice for detecting recurrence after parathyroid gland surgery?
Primary Hyperparathyroidism is associated with -
After a total thyroidectomy, the surgeon is unable to extubate the patient, who shows cyanosis and respiratory distress. What is the most likely cause of the inability to extubate?
Which type of thyroid cancer is associated with primary hyperparathyroidism and phaeochromocytoma?
Primary Hyperparathyroidism Indian Medical PG Practice Questions and MCQs
Question 1: In hypoparathyroidism:
- A. Plasma calcium is high and inorganic phosphorous low
- B. Plasma calcium and inorganic phosphorous are low
- C. Plasma calcium is low and inorganic phosphorous high (Correct Answer)
- D. Plasma calcium and inorganic phosphorous are high
Explanation: ***Plasma calcium is low and inorganic phosphorous high*** - **Hypoparathyroidism** is characterized by insufficient parathyroid hormone (PTH) production, leading to decreased bone resorption and reduced renal reabsorption of calcium [1]. This results in **hypocalcemia** (low plasma calcium) [1]. - PTH also promotes renal excretion of phosphate [2]. With insufficient PTH, renal phosphate excretion is impaired, leading to **hyperphosphatemia** (high inorganic phosphorus) [1]. *Plasma calcium is high and inorganic phosphorous low* - This profile is characteristic of **primary hyperparathyroidism**, where excessive PTH causes increased bone resorption and renal calcium reabsorption (high calcium), and increased renal phosphate excretion (low phosphorus). - It directly contradicts the defining features of hypoparathyroidism [1]. *Plasma calcium and inorganic phosphorous are low* - While plasma calcium is low in hypoparathyroidism, plasma inorganic phosphorus is characteristically high, not low [1]. - A combination of low calcium and low phosphorus can be seen in conditions like **vitamin D deficiency** (osteomalacia), but not directly in pure hypoparathyroidism [1]. *Plasma calcium and inorganic phosphorous are high* - This combination of high calcium and high phosphorus is uncommon and not typically seen in either hypoparathyroidism or hyperparathyroidism. - It could potentially indicate conditions like **milk-alkali syndrome** or **vitamin D intoxication**, but not hypoparathyroidism, which is defined by low calcium [1].
Question 2: A patient presented with complaints of pain in the flank region with hematuria. On investigation, X-ray shows multiple calcification (stones) in both kidneys. What is the probable diagnosis?
- A. Polycystic kidney disease
- B. Parathyroid Adenoma
- C. Renal calculi (Correct Answer)
- D. CKD
Explanation: ***Renal calculi*** - The presence of **flank pain**, **hematuria**, and **multiple calcifications (stones) in both kidneys** on X-ray directly points to a diagnosis of renal calculi (kidney stones) [1]. - These stones can cause pain due to obstruction and irritation, leading to blood in the urine [1]. *Polycystic kidney disease* - This condition is characterized by the development of numerous **cysts in the kidneys**, which are fluid-filled sacs, not calcifications or stones [2]. - While it can cause flank pain and hematuria, the imaging finding of **multiple calcifications** is inconsistent with typical PCKD presentation [2]. *Parathyroid Adenoma* - A parathyroid adenoma leads to **hyperparathyroidism**, which can cause **hypercalcemia** and subsequently increase the risk of **calcium kidney stones** [1]. - However, the diagnosis directly relates to the presence of stones as seen on X-ray, not the underlying cause of stone formation, and the question does not provide enough information to confirm hyperparathyroidism. *CKD* - **Chronic kidney disease (CKD)** is a progressive loss of kidney function over time, representing a *spectrum* of kidney damage. - While kidney stones can lead to CKD, and CKD can present with various symptoms, the direct finding of **multiple calcifications (stones)** on imaging is a specific indicator of renal calculi rather than CKD itself as the primary diagnosis.
Question 3: What is the initial treatment of choice for managing secondary hyperparathyroidism in patients with renal osteodystrophy?
- A. Cinacalcet
- B. Bisphosphonates
- C. Calcium restriction
- D. Phosphate binders (Correct Answer)
Explanation: ***Phosphate binders*** - **Phosphate binders** are the initial treatment because **hyperphosphatemia** is the primary driver of secondary hyperparathyroidism in renal disease, triggering parathyroid hormone (PTH) release [1]. - They work by binding dietary phosphate in the gastrointestinal tract, preventing its absorption and thus lowering serum phosphate levels [1]. *Cinacalcet* - **Cinacalcet** is a calcimimetic that increases the sensitivity of calcium-sensing receptors on the parathyroid gland, reducing **PTH secretion** [1]. - It is often used if **phosphate binders** and **vitamin D analogs** are insufficient in controlling PTH, making it a second-line treatment [1]. *Bisphosphonates* - **Bisphosphonates** are used to treat osteoporosis by inhibiting osteoclast activity and reducing bone resorption. - They are generally contraindicated in advanced renal osteodystrophy due to concerns about adynamic bone disease and are not an initial treatment for **secondary hyperparathyroidism**. *Calcium restriction* - While restricting dietary calcium might seem intuitive, **hypocalcemia** is often a problem in renal disease due to impaired vitamin D activation [1]. - Overly restricting calcium can worsen hypocalcemia, which would further stimulate PTH release, thus it is not an initial treatment for **secondary hyperparathyroidism**.
Question 4: A 45-year-old man undergoes a parathyroidectomy given recurrent episodes of dehydration and kidney stones caused by hypercalcemia secondary to an elevated PTH level. He is recovering on the surgical floor on day 3. His temperature is 97.6°F (36.4°C), blood pressure is 122/81 mmHg, pulse is 84/min, respirations are 12/min, and oxygen saturation is 98% on room air. The patient is complaining of perioral numbness currently. What is the most appropriate management of this patient?
- A. Potassium
- B. TSH level
- C. Vitamin D
- D. Observation
- E. Calcium gluconate (Correct Answer)
Explanation: ***Calcium gluconate*** - The patient's presentation of **perioral numbness** following a parathyroidectomy, especially given a history of hypercalcemia, is highly suggestive of **hypocalcemia**. - **Calcium gluconate** is indicated for acute symptomatic hypocalcemia to rapidly raise serum calcium levels and alleviate symptoms. *Potassium* - There is no clinical indication for **potassium** supplementation; the symptom of perioral numbness is not associated with potassium imbalance. - Parathyroidectomy and hypercalcemia primarily affect calcium and phosphate metabolism, not typically potassium. *TSH level* - A **TSH level** is used to assess thyroid function, which is generally not directly affected by parathyroidectomy unless thyroid tissue was incidentally damaged. - The symptoms presented do not suggest a thyroid dysfunction. *Vitamin D* - While **vitamin D** is crucial for calcium absorption and might be used in chronic management of hypocalcemia, it would not provide the immediate relief needed for acute symptomatic hypocalcemia. - Acute symptoms like perioral numbness require a rapid elevation of serum calcium. *Observation* - **Observation** is inappropriate given the patient's symptomatic presentation of **perioral numbness**, which indicates acute and potentially worsening hypocalcemia. - Untreated symptomatic hypocalcemia can progress to more severe complications such as seizures, arrhythmias, and laryngospasm.
Question 5: A patient develops recurrent hyperparathyroidism 2 years after initial parathyroidectomy and has experienced cardiovascular complications due to persistent hypercalcemia. What is the most appropriate management?
- A. Repeat neck surgery
- B. Observation and repeat serum Ca2+ in two months
- C. Repeat parathyroidectomy after medical optimization (Correct Answer)
- D. Medical management with calcimimetics (cinacalcet)
Explanation: ***Repeat parathyroidectomy after medical optimization*** - Recurrent **hyperparathyroidism** often requires repeat surgery, particularly in patients who have experienced cardiovascular events, as persistent hypercalcemia can exacerbate cardiac risk. - **Medical optimization** of cardiovascular conditions and metabolic status before reoperation is crucial to minimize surgical risks and improve outcomes. *Repeat neck surgery* - While repeat neck surgery is often necessary, this option is incomplete as it does not sufficiently emphasize the importance of **medical optimization** in patients with a history of cardiovascular events. - Performing surgery without adequate pre-operative evaluation and optimization can lead to increased **perioperative complications** in this high-risk group. *Observation and repeat serum Ca2+ in two months* - **Observation** is generally not appropriate for recurrent hyperparathyroidism, especially when it has already led to cardiovascular events, as continued hypercalcemia poses significant long-term health risks. - Delaying definitive treatment allows for ongoing end-organ damage, including worsening **cardiovascular disease** and bone complications. *Medical management with calcimimetics (cinacalcet)* - **Calcimimetics** like **cinacalcet** can reduce parathyroid hormone (PTH) and calcium levels, but they are typically used as an adjunct or for patients who are not surgical candidates. - In cases of recurrent hyperparathyroidism, especially with clinical sequelae like cardiovascular events, **surgical removal of the adenoma** remains the definitive treatment to achieve a cure.
Question 6: What is the most common cause of hypercalcemic crisis?
- A. Carcinoma of the breast
- B. Parathyroid adenoma (Correct Answer)
- C. Parathyroid hyperplasia
- D. Paget's disease
Explanation: ***Parathyroid adenoma*** - **Primary hyperparathyroidism**, most often caused by a solitary parathyroid adenoma, is the leading cause of hypercalcemic crisis, though this is rare [1][2]. - The adenoma autonomously overproduces **parathyroid hormone (PTH)**, leading to increased calcium reabsorption from bone and kidneys, and enhanced intestinal calcium absorption [1]. *Carcinoma of the breast* - While breast carcinoma can lead to **hypercalcemia** through bony metastases or parathyroid hormone-related peptide (PTHrP) production, it's not the most common cause of hypercalcemic crisis. - Metastatic bone disease is a common cause of hypercalcemia in malignancy, but the extent of hypercalcemia varies. *Parathyroid hyperplasia* - **Parathyroid hyperplasia** is a rarer cause of primary hyperparathyroidism compared to adenoma, and thus less frequently causes hypercalcemic crisis [2]. - All four parathyroid glands are typically enlarged and overactive, leading to excessive PTH secretion. *Paget's disease* - **Paget's disease of bone** primarily causes localized areas of increased bone turnover and can lead to elevated **alkaline phosphatase** levels. - It rarely causes significant hypercalcemia, and even more rarely a hypercalcemic crisis, unless there is prolonged immobilization or coexisting hyperparathyroidism.
Question 7: What is the investigation of choice for detecting recurrence after parathyroid gland surgery?
- A. SPECT
- B. MRI
- C. Neck ultrasound
- D. Sestamibi scan (Correct Answer)
Explanation: ***Sestamibi scan*** - A **sestamibi scan** is the investigation of choice for **localizing recurrent or persistent hyperparathyroidism** because **parathyroid tissue preferentially retains the tracer** longer than thyroid tissue. - This nuclear medicine imaging technique helps identify ectopic or very small parathyroid adenomas, which may be difficult to locate with other methods. *SPECT* - **Single-photon emission computed tomography (SPECT)** can be used as an adjunct to a sestamibi scan (SPECT-Sestamibi) to provide 3D images and improve localization, but it is typically not the initial or standalone investigation of choice for recurrence. - While SPECT offers increased sensitivity and specificity over planar imaging by removing superimposed structures, the **sestamibi uptake itself is the crucial diagnostic marker**. *MRI* - **Magnetic resonance imaging (MRI)** is generally used for detailed anatomical assessment of the neck and mediastinum, especially if there's concern for **ectopic glands or complex anatomy**. - However, it is less sensitive than sestamibi for detecting small or recurrent hyperactive parathyroid tissue due to its reliance on anatomical rather than functional abnormalities. *Neck ultrasound* - **Neck ultrasound** is an excellent initial imaging modality for primary hyperparathyroidism due to its **affordability and ability to visualize cervical parathyroid glands**. - For detecting recurrence, its utility is limited, especially in cases of **ectopic glands** (e.g., in the mediastinum) or if scar tissue hinders clear visualization.
Question 8: Primary Hyperparathyroidism is associated with -
- A. Increased serum PTH and Hypercalcemia (Correct Answer)
- B. Decreased serum PTH and Hyporcalcemia
- C. Decreased serum PTH and Hypercalcemia
- D. Increased serum PTH and Hyporcalcemia
Explanation: ***Increased serum PTH and Hypercalcemia*** - **Primary hyperparathyroidism** results from an autonomous overproduction of **parathyroid hormone (PTH)**, usually by an adenoma or hyperplasia [1]. - This excess PTH leads to increased calcium reabsorption from bones and kidneys, causing **hypercalcemia** [2][4]. *Decreased serum PTH and Hyporcalcemia* - This combination is characteristic of **hypoparathyroidism**, where insufficient PTH production leads to low calcium levels [3]. - Primary hyperparathyroidism, by definition, involves *increased* PTH [4]. *Decreased serum PTH and Hypercalcemia* - This might be seen in cases of **non-PTH-mediated hypercalcemia**, such as malignancy, where high calcium levels suppress normal PTH secretion [4]. - However, in primary hyperparathyroidism, PTH would be **elevated** [1]. *Increased serum PTH and Hyporcalcemia* - This scenario typically points to **secondary hyperparathyroidism**, where the parathyroid glands are overactive in response to chronic low calcium levels (e.g., due to **chronic kidney disease** or **Vitamin D deficiency**) [1][3]. - In primary hyperparathyroidism, the elevated PTH directly *causes* hypercalcemia [4].
Question 9: After a total thyroidectomy, the surgeon is unable to extubate the patient, who shows cyanosis and respiratory distress. What is the most likely cause of the inability to extubate?
- A. Bilateral recurrent laryngeal nerve palsy (Correct Answer)
- B. Unilateral recurrent laryngeal nerve palsy
- C. Superior laryngeal nerve palsy
- D. Hemorrhage
Explanation: ***Bilateral recurrent laryngeal nerve palsy*** - After total thyroidectomy, injury to both **recurrent laryngeal nerves** can lead to paralysis of the abductor muscles of the vocal cords causing them to approximate, leading to **airway obstruction**, cyanosis, and respiratory distress. - This condition prevents successful extubation and often necessitates **reintubation** or **tracheostomy**. *Unilateral recurrent laryngeal nerve palsy* - Causes **hoarseness** due to unilateral vocal cord paralysis but typically does not result in severe airway obstruction or inability to extubate. - The unaffected vocal cord can usually compensate sufficiently to maintain an adequate airway for breathing. *Superior laryngeal nerve palsy* - Primarily affects the **protective reflexes of the larynx** and vocal cord tension (pitch), leading to issues like **aspiration risk** and a weak, breathy voice. - It does not directly cause vocal cord paralysis in a position that obstructs the airway. *Hemorrhage* - While a significant **post-operative hemorrhage** in the neck can cause airway compression and respiratory distress, it usually manifests as **neck swelling** and possibly hypovolemic shock. - The scenario explicitly states "inability to extubate," suggesting a vocal cord issue rather than external compression by a hematoma.
Question 10: Which type of thyroid cancer is associated with primary hyperparathyroidism and phaeochromocytoma?
- A. Medullary carcinoma of the thyroid (Correct Answer)
- B. Papillary carcinoma of the thyroid
- C. Anaplastic carcinoma of the thyroid
- D. Follicular carcinoma of the thyroid
Explanation: ***Medullary carcinoma of the thyroid*** - Associated with **multiple endocrine neoplasia (MEN) syndrome type 2**, which includes primary hyperparathyroidism and phaeochromocytoma [1]. - Medullary carcinoma arises from **C cells** (parafollicular cells) and is linked with **elevated calcitonin** levels. *Papillary carcinoma of the thyroid* - The most common type of thyroid cancer, but **not associated** with MEN syndromes. - Typically presents as a solitary **nodule** and is linked with **radiation exposure** rather than endocrine syndromes. *Anaplastic carcinoma of the thyroid* - A highly aggressive and undifferentiated form of thyroid cancer, often associated with **poor prognosis**. - Usually arises in older adults and does not have associations with **hyperparathyroidism** or phaeochromocytoma. *Follicular carcinoma of the thyroid* - Characterized by **thyroid follicle formation** and can be associated with **iodine deficiency**, but not with MEN syndromes. - It usually presents as a **solitary thyroid nodule** and lacks connection with **primary hyperparathyroidism**.
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