Endocrine Surgery — MCQs

A 23-year-old woman undergoes total thyroidectomy for carcinoma of the thyroid gland. On the second postoperative day, she begins to complain of a tingling sensation in her hands and appears anxious, later complaining of muscle cramps. Which of the following is the most appropriate initial management strategy?

Q319

A post-thyroidectomy patient develops signs and symptoms of tetany. The management is:

Q320

Hypoparathyroidism following thyroid surgery occurs within:

Endocrine Surgery Indian Medical PG Practice Questions and MCQs

Question 311: Which of the following statements accurately describes a subtotal thyroidectomy?

A. Removal of one lobe and isthmus
B. Removal of 1 lobe with isthmus and the second lobe partially (Correct Answer)
C. Removal of both lobes leaving behind 6-8 grams of tissue
D. Removal of entire thyroid with cervical lymphnodes

Explanation: ***Removal of 1 lobe with isthmus and the second lobe partially*** - A **subtotal thyroidectomy** involves removing one complete thyroid lobe along with the isthmus, and partially resecting the contralateral lobe, leaving behind a small remnant of approximately **4-8 grams** on one side. - This procedure preserves parathyroid function and the recurrent laryngeal nerve while reducing thyroid tissue, commonly used for **bilateral multinodular goiter** or **Graves' disease**. - The retained remnant maintains some thyroid function and reduces the risk of permanent **hypothyroidism** and **hypoparathyroidism**. *Removal of one lobe and isthmus* - This describes a **hemithyroidectomy** or **thyroid lobectomy**, which involves complete removal of one lobe with the isthmus. - It is typically performed for **unilateral thyroid nodules**, **follicular neoplasms**, or small **well-differentiated thyroid cancers**. - It does not involve any resection of the contralateral lobe. *Removal of both lobes leaving behind 6-8 grams of tissue* - This would describe a **bilateral subtotal thyroidectomy**, where tissue is left on both sides. - While historically performed, this is **not the standard definition** of "subtotal thyroidectomy," which specifically refers to leaving remnant tissue on only one side. - Modern practice has largely replaced this with more definitive procedures. *Removal of entire thyroid with cervical lymphnodes* - This describes a **total thyroidectomy with central or lateral neck dissection**, performed for **thyroid malignancies** with lymph node involvement. - It aims to achieve complete oncological clearance and is followed by radioactive iodine therapy in differentiated thyroid cancers. - No thyroid tissue is intentionally preserved.

Question 312: What is the most common cause of lateral aberrant thyroid tissue?

A. Ectopic thyroid tissue due to developmental anomalies
B. Thyroid tissue in the mediastinum
C. Metastatic thyroid carcinoma (Correct Answer)
D. Lingual thyroid

Explanation: ***Metastatic thyroid carcinoma*** - **Metastatic papillary thyroid carcinoma** to cervical lymph nodes is the most common cause of lateral aberrant thyroid tissue - The term "lateral aberrant thyroid" is a **historical misnomer** that has been abandoned in modern thyroid surgery - What was previously thought to be ectopic thyroid tissue in lateral neck nodes is virtually always **metastatic disease** - Papillary thyroid carcinoma commonly metastasizes to **regional lymph nodes**, which then contain thyroid follicular cells - This represents **lymph node metastases**, not developmental ectopia *Ectopic thyroid tissue due to developmental anomalies* - True developmental ectopia of thyroid tissue in the **lateral neck is extremely rare to nonexistent** - The thyroid gland originates from the **foramen cecum in the midline** and descends along the thyroglossal duct - Developmental ectopic thyroid occurs in **midline structures** (lingual thyroid, thyroglossal duct remnants), not laterally - The concept of "lateral aberrant thyroid" as a developmental anomaly has been **disproven** *Thyroid tissue in the mediastinum* - Mediastinal thyroid tissue represents **substernal or retrosternal goiter** that has descended into the chest - This describes a different anatomical location (mediastinum vs. lateral neck) - Not related to lateral cervical masses *Lingual thyroid* - Lingual thyroid is ectopic thyroid tissue located at the **base of the tongue** - This is a **midline structure**, not a lateral neck finding - Represents failure of thyroid descent during embryological development

Question 313: What is the treatment of choice for medullary carcinoma of the thyroid?

A. I-131 ablation
B. Total thyroidectomy (Correct Answer)
C. Partial thyroidectomy
D. Hemithyroidectomy

Explanation: ***Total thyroidectomy*** - This is the **treatment of choice for medullary thyroid carcinoma (MTC)** due to its multifocal nature and high propensity for lymph node metastasis - **Complete surgical resection** (often with central compartment neck dissection) provides the best chance for cure by removing all thyroid tissue and involved lymph nodes - MTC arises from **parafollicular C cells** (calcitonin-producing cells) and frequently involves both lobes, making total thyroidectomy essential *Partial thyroidectomy* - This procedure removes only a portion of the thyroid gland, which is **insufficient for MTC** given its tendency for multifocality and bilateral involvement - Leaves residual thyroid tissue that could harbor undetected disease or develop future recurrences - Does not adequately address the aggressive nature of MTC *I-131 ablation* - **Radioactive iodine therapy** is effective for differentiated thyroid cancers (papillary and follicular) that take up iodine - MTC originates from **parafollicular C cells that do not concentrate iodine**, making I-131 ablation completely ineffective - This is a key distinguishing feature of MTC from other thyroid malignancies *Hemithyroidectomy* - This procedure removes only one thyroid lobe, which is **inadequate for MTC** - Risks leaving behind primary tumor in the contralateral lobe or occult bilateral disease - Fails to address the multifocal nature of MTC, particularly in hereditary cases (MEN 2A, MEN 2B, familial MTC)

Question 314: 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 315: A case of solitary thyroid nodule; the investigation of choice is:

A. T3, T4 estimation
B. Thyroid scan
C. FNAC (Correct Answer)
D. Excision biopsy

Explanation: ***Correct: FNAC*** - **Fine needle aspiration cytology (FNAC)** is the most important and definitive diagnostic tool for evaluating the malignancy risk of a **solitary thyroid nodule**. - It's a minimally invasive, cost-effective procedure with high sensitivity and specificity in differentiating **benign** from **malignant** lesions. - FNAC is recommended as the **first-line investigation** by major thyroid guidelines (ATA, BTA). *Incorrect: T3, T4 estimation* - **Thyroid hormone levels (T3, T4)** primarily assess thyroid function (hyperthyroidism or hypothyroidism), not the **malignancy potential** of a nodule itself. - While thyroid dysfunction can sometimes be associated with nodules, these tests alone cannot definitively diagnose or rule out cancer. - Thyroid function tests are complementary but not the primary investigation for nodule characterization. *Incorrect: Thyroid scan* - A **thyroid scan** (using radioactive iodine) helps determine if a nodule is "hot" (hyperfunctioning/benign) or "cold" (non-functioning/potentially malignant). - However, it cannot definitively differentiate between benign and malignant **cold nodules**, which require further investigation, typically FNAC. - Thyroid scanning has largely been superseded by ultrasound and FNAC in modern practice. *Incorrect: Excision biopsy* - **Excision biopsy** (surgical removal) is a treatment for a thyroid nodule rather than the initial investigation of choice. - It is typically performed when **FNAC results are indeterminate** or suspicious for malignancy, or when the nodule is significantly large or symptomatic. - This is an invasive procedure with surgical risks and is not appropriate as a first-line investigation.

Question 316: Following total thyroidectomy, the patient develops respiratory stridor. The cause is:

A. Unilateral recurrent laryngeal nerve paralysis
B. Unilateral phrenic nerve paralysis
C. Bilateral phrenic nerve paralysis
D. Bilateral recurrent laryngeal nerve paralysis (Correct Answer)

Explanation: ***Bilateral recurrent laryngeal nerve paralysis*** - **Bilateral recurrent laryngeal nerve paralysis** is a serious complication of total thyroidectomy, leading to **adductor paralysis** of both vocal cords. - This results in a narrowed airway, causing inspiratory **stridor**, **dyspnea**, and potentially acute respiratory obstruction requiring reintubation or tracheostomy. *Unilateral recurrent laryngeal nerve paralysis* - **Unilateral recurrent laryngeal nerve paralysis** typically causes **hoarseness** due to the inability of one vocal cord to adduct properly. - It does not usually cause **stridor** or significant respiratory distress because the other vocal cord can still compensate for airway patency. *Unilateral phrenic nerve paralysis* - **Unilateral phrenic nerve paralysis** affects one side of the **diaphragm**, causing **dyspnea** and reduced lung capacity, particularly during exertion. - It does not directly cause **stridor**, which is a sound produced by turbulent airflow through a narrowed upper airway. *Bilateral phrenic nerve paralysis* - **Bilateral phrenic nerve paralysis** causes severe **respiratory failure** due to complete paralysis of the **diaphragm**, requiring mechanical ventilation. - While life-threatening, it does not directly manifest as **stridor**, as the primary issue is the inability to move air in and out through the lower respiratory system, not an obstruction in the upper airway.

Question 317: 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 318: A 23-year-old woman undergoes total thyroidectomy for carcinoma of the thyroid gland. On the second postoperative day, she begins to complain of a tingling sensation in her hands and appears anxious, later complaining of muscle cramps. Which of the following is the most appropriate initial management strategy?

A. 10 mL of 10% magnesium sulfate intravenously
B. Oral vitamin D
C. 100 mg oral Synthroid
D. Continuous infusion of calcium gluconate (Correct Answer)

Explanation: ***Continuous infusion of calcium gluconate*** - The patient's symptoms of **tingling sensation in hands**, **anxiety**, and **muscle cramps** after a total thyroidectomy are highly suggestive of **hypocalcemia**, likely due to iatrogenic hypoparathyroidism. - An initial bolus followed by a **continuous infusion of calcium gluconate** is the most appropriate management for symptomatic hypocalcemia to rapidly replete calcium levels and prevent further complications. *10 mL of 10% magnesium sulfate intravenously* - While **hypomagnesemia** can sometimes cause refractory hypocalcemia, it is not the primary electrolyte abnormality indicated by these specific symptoms following thyroidectomy. - Administering magnesium sulfate as the initial and sole treatment would fail to address the underlying **calcium deficiency** directly and might delay appropriate management. *Oral vitamin D* - **Oral vitamin D** is used for chronic management of hypocalcemia, as it helps improve calcium absorption. - However, it has a slow onset of action and is not suitable for the **acute and symptomatic hypocalcemia** that requires immediate intervention. *100 mg oral Synthroid* - **Synthroid (levothyroxine)** is thyroid hormone replacement therapy, indicated for hypothyroidism following thyroidectomy. - While necessary for long-term management, it does not address the **acute symptoms of hypocalcemia** and would be inappropriate as an initial treatment for this emergent condition.

Question 319: A post-thyroidectomy patient develops signs and symptoms of tetany. The management is:

A. IV calcium gluconate (Correct Answer)
B. Bicarbonate
C. Calcitonin
D. Vitamin D

Explanation: ***IV calcium gluconate*** - **Tetany** after thyroidectomy is most commonly due to **hypocalcemia** from inadvertent **parathyroid gland removal** or damage, leading to decreased PTH production. - **Intravenous calcium gluconate** is the first-line treatment for acute, symptomatic hypocalcemia and tetany due to its rapid action in reversing neuromuscular excitability. *Bicarbonate* - Bicarbonate is used to treat **acidosis** and does not directly address hypocalcemia. - In fact, alkaline solutions like bicarbonate can **worsen hypocalcemia** by increasing protein binding of calcium, thus reducing ionized calcium levels. *Calcitonin* - **Calcitonin** is a hormone that **lowers serum calcium** by inhibiting osteoclast activity and increasing renal calcium excretion. - It would be contraindicated in a patient with hypocalcemic tetany as it would further decrease calcium levels. *Vitamin D* - **Vitamin D** (e.g., calcitriol) is essential for **long-term calcium absorption** and maintaining calcium homeostasis in chronic hypocalcemia. - However, its onset of action is too slow to treat acute, symptomatic tetany, which requires immediate calcium repletion.

Question 320: Hypoparathyroidism following thyroid surgery occurs within:

A. 2 - 5 days
B. 7-14 days
C. 24 hours (Correct Answer)
D. 2 - 3 weeks

Explanation: ***24 hours*** - **Symptomatic hypocalcemia** from hypoparathyroidism typically **begins within 24 hours** and peaks at **24-48 hours** post-thyroidectomy. - Serum calcium levels start to decline within the **first 24 hours** as parathyroid hormone (PTH) production decreases due to surgical trauma, ischemia, or inadvertent removal/damage to parathyroid glands. - Most patients who develop clinically significant hypoparathyroidism show **early signs** including perioral numbness, paresthesias, and positive Chvostek's or Trousseau's signs within this timeframe. - **Early monitoring** of calcium levels (usually at 6-12 hours postoperatively) is standard practice to detect and treat hypocalcemia promptly. *2 - 5 days* - While some cases may continue to worsen during this period, the **onset** typically occurs much earlier (within 24-48 hours). - This timeframe represents continuation or persistence of hypocalcemia rather than initial manifestation. - Waiting 2-5 days to detect hypoparathyroidism would be considered delayed diagnosis in modern practice. *7-14 days* - This timeframe is **too late** for acute postoperative hypoparathyroidism diagnosis. - By this time, the focus shifts to determining whether hypoparathyroidism is **transient** (resolving within 6 months) or **permanent**. - Most acute symptomatic cases have already been identified and are under treatment by this period. *2 - 3 weeks* - Hypoparathyroidism presenting at **2-3 weeks** would be highly unusual for post-thyroidectomy complications. - At this stage, clinicians are assessing for **recovery of parathyroid function** rather than initial onset. - **Permanent hypoparathyroidism** is only diagnosed if hypocalcemia persists beyond **6 months**, not at 2-3 weeks.

Practice by Chapter

Thyroid Nodules

Practice Questions

Thyroid Cancer

Practice Questions

Graves' Disease

Practice Questions

Thyroiditis

Practice Questions

Primary Hyperparathyroidism

Practice Questions

Secondary and Tertiary Hyperparathyroidism

Practice Questions

Adrenal Cortical Tumors

Practice Questions

Pheochromocytoma

Practice Questions

Adrenal Incidentalomas

Practice Questions

Multiple Endocrine Neoplasia

Practice Questions

Neuroendocrine Tumors

Practice Questions

Intraoperative Monitoring in Endocrine Surgery

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free