Endocrine Surgery — MCQs

In the evaluation of a 64-year-old woman with fluctuating neurological signs, including ptosis, eleventh and twelfth cranial nerve palsy, and generalized extremity weakness. Edrophonium (Tensilon) given intravenously results in clinical improvement. A computed tomography (CT) scan shows a lesion in the anterior mediastinum, and a biopsy confirms the presence of a thymoma. She should undergo which of the following?

Q329

A patient has hypocalcaemia, which was the result of a surgical complication. Which operation could it possibly have been?

Q330

Which of the following medications is not typically used in the preoperative management of thyrotoxicosis?

Endocrine Surgery Indian Medical PG Practice Questions and MCQs

Question 321: Which of the following factors is not included in the MACIS score used for the prognosis of papillary thyroid cancer?

A. Age
B. Size
C. Excision completion in surgery
D. Mitotic index (Correct Answer)

Explanation: ***Mitotic index*** - The MACIS score is a **prognostic scoring system** for papillary thyroid carcinoma, and the mitotic index is **not a component** of this score. - The MACIS score considers factors such as **Metastasis**, **Age**, **Completeness of excision**, **Invasion**, and **Size** of the tumor. *Age* - **Age** is a crucial factor in the MACIS score, with patients older than 40 years typically having a **worse prognosis**. - It differentiates between patients <40 years and ≥40 years, assigning different points based on age. *Size* - The **size** of the primary tumor is an important component of the MACIS score. - Tumors larger than 4 cm (or 40 mm) are associated with a **higher score** and a less favorable prognosis. *Excision completion in surgery* - The **completeness of surgical excision** is a critical factor in the MACIS score. - **Incomplete tumor removal** or gross residual tumor after surgery indicates a worse prognosis and adds points to the score.

Question 322: Which of the following is NOT a classification of retrosternal goiter?

A. Substernal.
B. Plunging.
C. Nodular goiter. (Correct Answer)
D. Intrathoracic.

Explanation: ***Nodular goiter*** - **Nodular goiter** describes the *morphology* of the thyroid gland (presence of nodules), not its anatomical location in relation to the sternum. - While a retrosternal goiter can certainly be nodular, "nodular goiter" itself is a description of the gland's structure rather than a classification of its retrosternal extension. *Substernal* - **Substernal goiter** is a common and interchangeable term for a retrosternal goiter, denoting its location partially or entirely *behind the sternum*. - This classification specifically describes the anatomical extension of the thyroid gland. *Plunging* - **Plunging goiter** refers to a thyroid gland that intermittently or permanently descends into the thoracic cavity, often exacerbated by a swallow or Valsalva maneuver. - This term highlights the dynamic movement characteristic of some retrosternal goiters. *Intrathoracic* - **Intrathoracic goiter** is another term used to describe a goiter located within the chest cavity, emphasizing its *position relative to the thoracic inlet*. - This classification is synonymous with retrosternal or substernal goiter, indicating its anatomical deep extension.

Question 323: Most common injured nerve after thyroidectomy is?

A. Superior laryngeal nerve
B. External laryngeal nerve
C. Recurrent laryngeal nerve (Correct Answer)
D. Nerve to omohyoid

Explanation: ***Recurrent laryngeal nerve*** - The **recurrent laryngeal nerves (RLNs)** are most frequently injured during thyroidectomy due to their close proximity to the thyroid gland and their variable anatomical course. - Injury to the RLN can result in **vocal cord paralysis**, causing hoarseness or aphonia. *External laryngeal nerve* - The **external laryngeal nerve (ELN)** is a branch of the superior laryngeal nerve and innervates the **cricothyroid muscle**, which tenses the vocal cords. - While it can be injured during thyroidectomy, especially during high ligation of the superior thyroid artery, it is less commonly injured than the recurrent laryngeal nerve. *Superior laryngeal nerve* - The **superior laryngeal nerve (SLN)** branches into the internal and external laryngeal nerves. While portions of the SLN or its branches (ELN) can be injured, the entire SLN is less commonly damaged than the recurrent laryngeal nerve. - Injury to the internal laryngeal nerve would affect sensation above the vocal cords, and injury to the external laryngeal nerve would affect pitch control. *Nerve to omohyoid* - The omohyoid muscle is a strap muscle in the neck, innervated by the **ansa cervicalis**, a branch of the cervical plexus. - This nerve is located far from the thyroid gland's surgical field and is therefore **very rarely injured** during a thyroidectomy.

Question 324: A middle-aged patient presents with a woody-hard thyroid gland that is fixed to surrounding structures and does not move with deglutition. The patient is euthyroid and the condition has been slowly progressive. What is the most likely diagnosis?

A. Anaplastic thyroid carcinoma.
B. Reidel's thyroiditis. (Correct Answer)
C. Retrosternal goitre.
D. None of the options.

Explanation: ***Reidel's thyroiditis*** - This rare condition involves **dense fibrosis** of the thyroid gland, causing it to become **woody-hard** and **fixed to surrounding structures** in the neck. - Key distinguishing features include **slow progression**, **euthyroid status**, and the thyroid gland being **rock-hard** on palpation. - The immobility due to fibrosis prevents the thyroid gland from moving with **deglutition**, a key clinical sign. *Anaplastic thyroid carcinoma* - While this aggressive cancer can also invade surrounding tissues and cause fixation, it presents very differently. - Characterized by **rapid growth** (weeks to months), elderly patients (>60 years), **compressive symptoms**, and often metastatic disease at presentation. - The clinical context of slow progression and euthyroid status makes this less likely. *Retrosternal goitre* - A **retrosternal goitre** is a thyroid enlargement that extends down into the chest behind the sternum. - The portion of the gland within the neck typically **moves with deglutition**, unless there are complications like hemorrhage or malignancy causing fixation. - Not characterized by woody-hard consistency. *None of the options* - This option is incorrect because Reidel's thyroiditis is the condition that best fits the clinical scenario described.

Question 325: A patient diagnosed with papillary carcinoma of the thyroid underwent a whole-body iodine scan six weeks after surgery, which revealed residual disease. The next best step is:

A. Surgical removal of residual disease
B. Radioiodine ablation (Correct Answer)
C. FNAC of the residual tissue followed by radioiodine ablation
D. Neck ultrasound and serum thyroglobulin level measurement

Explanation: ***Radioiodine ablation*** - **Radioiodine (RAI) ablation** is the standard treatment for residual thyroid cancer after surgery, especially for **papillary thyroid carcinoma**, which typically avidly takes up iodine. - The goal is to destroy any remaining microscopic thyroid cells or cancer cells that may not have been removed surgically. - This is the **next best step** when residual disease is detected on whole-body iodine scan. *Surgical removal of residual disease* - While surgical removal is a primary treatment, attempting another surgery for **microscopic residual disease** detected by a whole-body scan might be difficult and carry higher risks. - RAI ablation is generally preferred for **diffuse residual disease** or microscopic foci that are not amenable to surgical resection. *FNAC of the residual tissue followed by radioiodine ablation* - **Fine needle aspiration cytology (FNAC)** typically targets discrete nodules, and the whole-body scan indicates diffuse or multifocal residual tissue, making FNAC less practical. - Since the diagnosis of **papillary carcinoma** is already established histologically, re-biopsy of residual tissue is unnecessary before RAI ablation, especially if the residual disease is diffuse. - This would cause unnecessary delay in definitive treatment. *Neck ultrasound and serum thyroglobulin level measurement* - These are **diagnostic and monitoring tools**, not definitive treatments for established residual disease. - While crucial for initial evaluation and ongoing surveillance, they do not eliminate the residual cancer, which is the immediate priority.

Question 326: What is the most appropriate surgical treatment for primary hyperparathyroidism?

A. Removal of all four glands
B. Calcitonin
C. Removal of all glands leaving 50 mg of tissue as remnant
D. Removal of the abnormal gland(s) with preservation of normal glands (Correct Answer)

Explanation: ***Removal of the abnormal gland(s) with preservation of normal glands*** - The standard surgical approach for **primary hyperparathyroidism** involves selectively identifying and resecting only the **hyperfunctioning gland(s)**, which are usually a single solitary adenoma. - This **minimally invasive parathyroidectomy** aims to restore normal calcium levels while preserving healthy parathyroid tissue to prevent hypoparathyroidism. *Removal of all four glands* - This approach would lead to **permanent hypoparathyroidism**, requiring lifelong calcium and vitamin D supplementation. - It is generally reserved for rare cases of widespread parathyroid hyperplasia or carcinoma where selective removal is not feasible. *Calcitonin* - **Calcitonin** is a hormone that lowers blood calcium levels but is not a surgical treatment for hyperparathyroidism. - It might be used as a medical therapy in specific situations but does not address the underlying glandular pathology. *Removal of all glands leaving 50 mg of tissue as remnant* - This procedure, known as **subtotal parathyroidectomy**, is typically performed for cases of **secondary or tertiary hyperparathyroidism** where all glands are hyperplastic. - In primary hyperparathyroidism, where typically only one gland is adenomatous, this extensive removal is unnecessary and carries a higher risk of postoperative hypoparathyroidism.

Question 327: A 4 cm thyroid nodule that is mobile but causing compressive symptoms presents several considerations. Which of the following statements is false?

A. Management may include subtotal thyroidectomy in certain cases.
B. FNAC cannot reliably distinguish between follicular adenoma and carcinoma.
C. Cold nodules are always malignant. (Correct Answer)
D. FNAC is the first-line investigation of choice for thyroid nodules.

Explanation: ***Cold nodules are always malignant.*** - This statement is **false** because while **cold nodules** (those that do not take up radioactive iodine on scintigraphy) have a higher risk of malignancy compared to hot nodules, the vast majority are still **benign**. - Approximately **80-85% of cold nodules are benign**, emphasizing that a cold appearance on scan is an indicator for further investigation, not a definitive diagnosis of cancer. *FNAC is the first-line investigation of choice for thyroid nodules.* - This statement is **true** as fine needle aspiration cytology (**FNAC**) is the **first-line investigation** for evaluating thyroid nodules. - It is minimally invasive, cost-effective, and has high sensitivity and specificity for diagnosing thyroid malignancy. *Management may include subtotal thyroidectomy in certain cases.* - This statement is **true** as **subtotal thyroidectomy** can be considered for **benign multinodular goiter** causing compressive symptoms, especially when total thyroidectomy is deemed too aggressive or increases complication risk. - This approach aims to relieve compression while preserving some thyroid function. *FNAC cannot reliably distinguish between follicular adenoma and carcinoma.* - This statement is **true** because the distinction between a **follicular adenoma** (benign) and a **follicular carcinoma** (malignant) relies on identifying **capsular or vascular invasion**, which cannot be assessed by cytology alone. - A **surgical biopsy** like lobectomy is often required for definitive diagnosis of follicular lesions.

Question 328: In the evaluation of a 64-year-old woman with fluctuating neurological signs, including ptosis, eleventh and twelfth cranial nerve palsy, and generalized extremity weakness. Edrophonium (Tensilon) given intravenously results in clinical improvement. A computed tomography (CT) scan shows a lesion in the anterior mediastinum, and a biopsy confirms the presence of a thymoma. She should undergo which of the following?

A. High-dose steroid therapy
B. Radiation therapy for the anterior mediastinum
C. Calcium supplementation
D. Thymectomy (Correct Answer)

Explanation: ***Thymectomy*** - The combination of **fluctuating neurological signs** (ptosis, cranial nerve palsies, generalized weakness) improving with **edrophonium** strongly suggests **myasthenia gravis**. - **Thymomas** are present in 10-15% of myasthenia gravis patients; **thymectomy** is indicated for nearly all patients with thymoma, regardless of tumor stage, as it can lead to improvement or remission of myasthenic symptoms and is crucial for tumor removal. *High-dose steroid therapy* - While **steroids** can be used to treat symptoms of **myasthenia gravis**, they are typically used for symptom control or as an adjunct to surgery, not as the primary curative treatment, especially in the presence of a **thymoma**. - Steroids do not address the underlying **thymoma**, which needs surgical removal. *Radiation therapy for the anterior mediastinum* - **Radiation therapy** for a **thymoma** is usually considered as an adjunctive treatment after surgery, for unresectable tumors, or in cases of recurrence. - It is not the primary treatment when surgery (thymectomy) is a viable option for tumor removal. *Calcium supplementation* - **Calcium supplementation** is not relevant to the treatment of **myasthenia gravis** or **thymoma**. - This intervention would be appropriate for conditions like hypocalcemia, which is not indicated by the patient's symptoms.

Question 329: A patient has hypocalcaemia, which was the result of a surgical complication. Which operation could it possibly have been?

A. Thyroidectomy (Correct Answer)
B. Nephrectomy
C. Vocal cord tumor biopsy
D. Gastrectomy

Explanation: ***Thyroidectomy*** - **Hypocalcemia** is a common complication of thyroidectomy due to **unintentional removal** or **damage to the parathyroid glands** during surgery. - The parathyroid glands regulate calcium levels, and their impairment leads to decreased **parathyroid hormone (PTH)** production, resulting in low serum calcium. *Nephrectomy* - **Nephrectomy** involves the surgical removal of a kidney and is not directly associated with immediate postoperative hypocalcemia as a typical complication. - While chronic kidney disease can affect calcium metabolism, the acute removal of a kidney does not primarily cause **hypocalcemia**. *Vocal cord tumor biopsy* - A **vocal cord tumor biopsy** is a procedure typically performed through the mouth or a small incision in the neck, focusing on the larynx. - This procedure usually does not involve structures critical for calcium regulation, such as the parathyroid glands, and therefore, **hypocalcemia** is not an expected complication. *Gastrectomy* - **Gastrectomy** is the surgical removal of part or all of the stomach, most commonly performed for stomach cancer or severe ulcers. - While long-term issues like **malabsorption** of calcium and vitamin D can occur after gastrectomy, acute postoperative **hypocalcemia** due to surgical damage to calcium-regulating glands is not typical.

Question 330: Which of the following medications is not typically used in the preoperative management of thyrotoxicosis?

A. Nifedipine (Correct Answer)
B. Propranolol
C. Carbimazole
D. Lugol's Iodine

Explanation: ***Nifedipine*** - **Nifedipine** is a **calcium channel blocker** used for hypertension and angina, but it has no role in the direct management of **thyrotoxicosis** or stabilization for thyroid surgery. - Its primary mechanism of action involves **vasodilation**, which is not beneficial for reducing thyroid hormone synthesis or release. *Propranolol* - **Propranolol** is a **beta-blocker** that helps control the **symptomatic effects** of thyrotoxicosis, such as tachycardia, tremors, and anxiety. - It also *inhibits the peripheral conversion of T4 to T3*, making it a crucial component of preoperative management. *Carbimazole* - **Carbimazole** is an **antithyroid drug** that *inhibits the synthesis of thyroid hormones* by blocking the enzyme **thyroid peroxidase**. - It is used to achieve a **euthyroid state** before surgery, reducing the risk of complications such **as thyroid storm**. *Lugol's Iodine* - **Lugol's Iodine** **acutely blocks the release of pre-formed thyroid hormones** from the thyroid gland and **reduces the vascularity of the gland**, making surgery safer. - It is typically administered **10-14 days before surgery** after antithyroid medications have been initiated.

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

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