Endocrine Surgery US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Endocrine Surgery. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Endocrine Surgery US Medical PG Question 1: A 50-year-old woman comes to the physician because of palpitations and irritability. Over the past 4 months, she has had several episodes of heart racing and skipping beats that lasted between 30 seconds and several hours. She has also been arguing with her husband more, often about the temperature being too warm. The patient has also lost 8.8-kg (19.4-lb) over the past 4 months, despite being less strict with her diet. She has mild asthma treated with inhaled bronchodilators. Her pulse is 102/min and blood pressure is 148/98 mm Hg. On physical examination, the skin is warm and moist. A mass is palpated in the anterior neck area. On laboratory studies, thyroid stimulating hormone is undetectable and there are antibodies against the thyrotropin-receptor. Thyroid scintigraphy shows diffusely increased iodine uptake. Two weeks later, a single oral dose of radioactive iodine is administered. This patient will most likely require which of the following in the long-term?
- A. Propranolol therapy
- B. Near-total thyroidectomy
- C. L-thyroxine therapy (Correct Answer)
- D. Methimazole therapy
- E. Estrogen replacement therapy
Endocrine Surgery Explanation: * ***L-thyroxine therapy***
* Radioactive iodine ablation for **Graves' disease** often leads to **permanent hypothyroidism**, necessitating **lifelong thyroid hormone replacement** with levothyroxine.
* The patient presents with classic **hyperthyroidism** symptoms (palpitations, irritability, weight loss, heat intolerance, warm/moist skin, goiter, undetectable TSH, positive **TSH receptor antibodies**, diffuse uptake on scintigraphy), treated with radioactive iodine.
* *Propranolol therapy*
* Propranolol is a **beta-blocker** used for symptomatic relief of hyperthyroidism, particularly palpitations and tremors.
* It does **not treat the underlying cause** of hyperthyroidism or subsequent hypothyroidism, and therefore is not a long-term solution after successful radioactive iodine therapy.
* *Near-total thyroidectomy*
* A near-total thyroidectomy is a surgical option for hyperthyroidism, especially in cases of very large goiters, contraindications to radioactive iodine, or malignancy.
* While it also often leads to **hypothyroidism** requiring long-term L-thyroxine, it was **not the chosen treatment modality** in this scenario (radioactive iodine was administered).
* *Methimazole therapy*
* Methimazole is an **antithyroid drug** used to decrease thyroid hormone synthesis in hyperthyroidism.
* It is used as a **primary treatment for hyperthyroidism** or as preparation for definitive therapy like radioactive iodine or surgery; it is not a long-term treatment after successful radioactive iodine ablation has induced hypothyroidism.
* *Estrogen replacement therapy*
* Estrogen replacement therapy is used for symptoms of **menopause** or to prevent osteoporosis, but it has no direct role in the management of thyroid disorders.
* The patient's symptoms are clearly indicative of a **thyroid pathology**, not primarily menopausal symptoms.
Endocrine Surgery US Medical PG Question 2: A 31-year-old man comes to the physician because of worsening abdominal pain, an inability to concentrate at work, and a general lack of motivation over the past several months. He has a history of spontaneous passage of two kidney stones. His father and uncle underwent thyroidectomy before the age of 35 for thyroid cancer. Physical examination shows diffuse tenderness over the abdomen. Serum studies show:
Na+ 142 mEq/L
K+ 3.7 mEq/L
Glucose 131 mg/dL
Ca2+ 12.3 mg/dL
Albumin 4.1 g/dL
Parathyroid hormone 850 pg/mL
Further evaluation is most likely to show elevated levels of which of the following?
- A. Serum aldosterone to renin ratio
- B. Serum prolactin
- C. Urine metanephrines (Correct Answer)
- D. Urine 5-hydroxyindoleacetic acid
- E. Midnight salivary cortisol
Endocrine Surgery Explanation: ***Urine metanephrines***
- The patient's presentation with **hypercalcemia** (Ca2+ 12.3 mg/dL) and **elevated PTH** (850 pg/mL) indicates **hyperparathyroidism**.
- The family history of **thyroidectomy for thyroid cancer before age 35** (medullary thyroid cancer) along with hyperparathyroidism points towards **Multiple Endocrine Neoplasia type 2 (MEN2)**. MEN2 syndromes often include **pheochromocytoma**, which is diagnosed by elevated **urine metanephrines**.
*Serum aldosterone to renin ratio*
- This ratio is used to screen for **primary hyperaldosteronism**, which presents with **hypertension and hypokalemia**.
- The patient's blood pressure is not mentioned as elevated, and his **potassium (3.7 mEq/L) is within normal limits**, making primary hyperaldosteronism less likely.
*Serum prolactin*
- Elevated serum prolactin levels indicate **hyperprolactinemia**, which is a feature of **MEN1 (Multiple Endocrine Neoplasia type 1)**.
- While MEN1 also includes hyperparathyroidism, the family history of **early-onset thyroid cancer** (suggesting medullary thyroid cancer, not typically seen in MEN1) points more strongly to MEN2.
*Urine 5-hydroxyindoleacetic acid*
- Elevated levels of **5-HIAA in urine** are indicative of a **carcinoid tumor**, which secretes serotonin.
- Carcinoid tumors are not typically associated with the constellation of symptoms and family history presented, particularly hyperparathyroidism and early-onset medullary thyroid cancer.
*Midnight salivary cortisol*
- This test is used to diagnose **Cushing's syndrome**, which is characterized by elevated cortisol levels and symptoms like central obesity, moon facies, and striae.
- The patient's symptoms are not consistent with Cushing's syndrome, and the laboratory findings (hypercalcemia, elevated PTH) point to a different endocrine disorder.
Endocrine Surgery US Medical PG Question 3: A 40-year-old woman comes to the physician because of a 3-month history of a lump on her neck. The lump is mildly painful. She appears healthy. Examination shows a swelling on the left side of her neck that moves on swallowing. Cardiopulmonary examination shows no abnormalities. Her TSH is 3.6 μU/mL. Ultrasound shows a 4.0-cm (1.6-in) hypoechoic mass in the left thyroid lobe. Fine-needle aspiration of the mass shows neoplastic follicular cells. Molecular analysis of the aspirate shows a mutation in the RAS gene. Which of the following is the most appropriate next step in management?
- A. Radioiodine therapy
- B. External beam radiation
- C. Total thyroidectomy
- D. Thyroid lobectomy (Correct Answer)
- E. Watchful waiting
Endocrine Surgery Explanation: ***Thyroid lobectomy***
- A **thyroid lobectomy** is appropriate for a **solitary thyroid nodule** with suspicious features (hypoechoic, neoplastic follicular cells, **RAS mutation**) and a size of 4.0 cm, as it allows for pathological diagnosis and treatment while preserving the other lobe.
- The **RAS mutation** indicates a moderate risk of malignancy, and for a unilateral tumor of this size, lobectomy is often preferred over total thyroidectomy as it minimizes the risk of **hypoparathyroidism** and the need for lifelong thyroid hormone replacement.
*Radioiodine therapy*
- This therapy is primarily used as an **adjunctive treatment** after surgical removal of thyroid cancer, especially for **metastatic disease** or **large residual tumors**, not as a primary treatment for a localized tumor before surgery.
- It is also typically reserved for **differentiated thyroid cancers** (papillary, follicular) that have demonstrated uptake, and surgical removal is the initial step for diagnosis and treatment.
*External beam radiation*
- **External beam radiation** is generally reserved for **advanced, inoperable thyroid cancers** or for cases with **extracapsular invasion** or **distant metastases** that are not amenable to radioiodine therapy.
- It carries significant side effects and is not a first-line treatment for an early-stage, localized thyroid nodule.
*Total thyroidectomy*
- **Total thyroidectomy** is indicated for larger thyroid cancers (>4 cm), bilateral disease, or aggressive histological subtypes.
- Given the patient's **unilateral tumor** with a **RAS mutation** (which signifies moderate risk), a thyroid lobectomy is appropriate as the initial surgical approach, with total thyroidectomy reserved if final pathology shows aggressive features.
*Watchful waiting*
- **Watchful waiting** is inappropriate given the presence of **neoplastic follicular cells** and a **RAS mutation**, as these findings indicate a significant risk of malignancy.
- The nodule size of 4.0 cm and molecular findings warrant surgical intervention for definitive diagnosis and treatment rather than observation.
Endocrine Surgery US Medical PG Question 4: Immediately after undergoing a right total knee replacement, a 69-year-old woman has severe abdominal pain, non-bloody emesis, and confusion. She has a history of Hashimoto thyroiditis that is well-controlled with levothyroxine and hyperlipidemia that is controlled by diet. She underwent bunion removal surgery from her right foot 10 years ago. Her temperature is 39°C (102.2°F), pulse is 120/min, and blood pressure is 60/30 mm Hg. Abdominal examination shows a diffusely tender abdomen with normal bowel sounds. She is confused and oriented to person but not place or time. Laboratory studies are pending. Which of the following is the most appropriate next step in the management of this patient?
- A. High-dose hydrocortisone
- B. Exploratory laparotomy
- C. CT angiogram of the abdomen
- D. Noncontrast CT of the head
- E. Intravenous isotonic saline infusion (Correct Answer)
Endocrine Surgery Explanation: ***Intravenous isotonic saline infusion***
- The patient presents with **shock** (BP 60/30 mm Hg, pulse 120/min, confusion), which is immediately life-threatening and requires urgent intervention.
- **IV fluid resuscitation** is the **first priority** in any shock state to restore intravascular volume, improve tissue perfusion, and stabilize hemodynamics.
- While this patient has features concerning for **acute adrenal crisis** (Hashimoto thyroiditis with possible polyglandular autoimmune syndrome, post-surgical stress, fever, hypotension, confusion), **fluid resuscitation must be initiated immediately** before or concurrent with other therapies.
- In practice, **high-dose hydrocortisone should be given simultaneously** with fluids, but restoring circulating volume is the foundational first step.
*High-dose hydrocortisone*
- This patient has **Hashimoto thyroiditis** and presents with shock after major surgery (a known precipitant), raising strong suspicion for **acute adrenal crisis**.
- Patients with autoimmune thyroid disease can have concurrent **autoimmune adrenal insufficiency** (Schmidt syndrome/APS-2).
- **Hydrocortisone is critical** and should be given immediately (typically 100 mg IV), but **not before addressing the shock state** with fluid resuscitation.
- This would be the appropriate **second step** or given concurrently with fluids.
*Exploratory laparotomy*
- While the patient has **severe abdominal pain** and **diffuse tenderness**, the overall presentation (fever, hypotension, post-op state) suggests **medical shock** rather than a surgical emergency.
- **Normal bowel sounds** make mechanical obstruction or perforation less likely.
- Surgery is inappropriate until the patient is hemodynamically stabilized and a surgical cause is confirmed.
*CT angiogram of the abdomen*
- This could evaluate for **mesenteric ischemia**, but the patient is **too unstable** for imaging.
- The clinical picture better fits **adrenal crisis** or **septic shock** rather than vascular catastrophe.
- **Delaying resuscitation** for imaging in a patient with severe hypotension would be harmful.
*Noncontrast CT of the head*
- The patient's **confusion** is most likely due to **hypoperfusion** and **shock** rather than a primary intracranial process.
- **Altered mental status** is a common manifestation of shock and adrenal crisis.
- Cerebral perfusion depends on adequate systemic blood pressure, making **circulatory stabilization the priority**.
Endocrine Surgery US Medical PG Question 5: A 20-year-old woman visits the clinic for her annual physical examination. She does not have any complaints during this visit. The past medical history is insignificant. She follows a healthy lifestyle with a balanced diet and moderate exercise schedule. She does not smoke or drink alcohol. She does not take any medications currently. The family history is significant for her grandfather and uncle who had their parathyroid glands removed. The vital signs include: blood pressure:122/88 mm Hg, pulse 88/min, respirations 17/min, and temperature 36.7°C (98.0°F). The physical exam is within normal limits. The lab test results are as follows:
Blood Urea Nitrogen 12 mg/dL
Serum Creatinine 1.1 mg/dL
Serum Glucose (Random) 88 mg/dL
Serum chloride 107 mmol/L
Serum potassium 4.5 mEq/L
Serum sodium 140 mEq/L
Serum calcium 14.5 mg/dL
Serum albumin 4.4 gm/dL
Parathyroid Hormone (PTH) 70 pg/mL (Normal: 10-65 pg/mL)
24-Hr urinary calcium 85 mg/day (Normal: 100–300 mg/day)
Which of the following is the next best step in the management of this patient?
- A. No treatment is necessary (Correct Answer)
- B. Start IV fluids to keep her hydrated
- C. Start her on pamidronate
- D. Give glucocorticoids
- E. Parathyroidectomy
Endocrine Surgery Explanation: ***No treatment is necessary***
- This patient has **familial hypocalciuric hypercalcemia (FHH)**, a benign autosomal dominant condition caused by inactivating mutations in the calcium-sensing receptor (CaSR).
- The key diagnostic triad is: **elevated serum calcium** (14.5 mg/dL), **mildly elevated or inappropriately normal PTH** (70 pg/mL), and **LOW 24-hour urinary calcium** (<100 mg/day).
- The family history of parathyroid surgery in relatives suggests they may have been misdiagnosed with primary hyperparathyroidism.
- **FHH is a benign condition that requires no treatment**. Patients are typically asymptomatic and do not develop complications of hypercalcemia.
- The calcium-creatinine clearance ratio (CCCR) is typically <0.01 in FHH, which helps distinguish it from primary hyperparathyroidism (CCCR >0.02).
*Parathyroidectomy*
- **Parathyroidectomy is contraindicated in FHH** and is a common error in management.
- Surgery does not correct the hypercalcemia in FHH because the defect is in the calcium-sensing receptor throughout the body, not in the parathyroid glands.
- Parathyroidectomy can lead to **permanent hypoparathyroidism** without resolving the underlying condition.
- Surgery is indicated for **primary hyperparathyroidism**, which differs from FHH by having normal or elevated urinary calcium excretion.
*Start IV fluids to keep her hydrated*
- IV fluids are used for **acute symptomatic hypercalcemia** or hypercalcemic crisis.
- This patient is **asymptomatic** with stable vital signs and does not require acute intervention.
- Fluids do not address the underlying pathophysiology of FHH and are unnecessary in this benign condition.
*Start her on pamidronate*
- Bisphosphonates like pamidronate are used for **hypercalcemia of malignancy** or severe symptomatic primary hyperparathyroidism.
- They are **ineffective in FHH** because the hypercalcemia is due to altered calcium sensing, not increased bone resorption.
- Pamidronate is not indicated for chronic management of asymptomatic hypercalcemia due to FHH.
*Give glucocorticoids*
- Glucocorticoids treat hypercalcemia from **granulomatous diseases** (sarcoidosis), **vitamin D intoxication**, or **hematologic malignancies** (lymphoma, multiple myeloma).
- They work by decreasing intestinal calcium absorption and are ineffective in FHH.
- This patient's clinical presentation and laboratory findings do not suggest any of these conditions.
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