Endocrine Surgery — MCQs

Endocrine Surgery Indian Medical PG Practice Questions and MCQs

Question 81: True regarding Papillary carcinoma of thyroid is:

A. Undifferentiated carcinoma
B. Blood-borne metastasis is commoner
C. Excellent prognosis (Correct Answer)
D. Capsulated

Explanation: **Explanation:** **Papillary Thyroid Carcinoma (PTC)** is the most common type of thyroid malignancy (80–85%). The correct answer is **Excellent prognosis** because PTC is a slow-growing, well-differentiated tumor with a 10-year survival rate exceeding 90–95%. **Analysis of Options:** * **A. Undifferentiated carcinoma:** Incorrect. PTC is a **well-differentiated** carcinoma. Anaplastic carcinoma is the undifferentiated type, which is highly aggressive. * **B. Blood-borne metastasis is commoner:** Incorrect. PTC characteristically spreads via the **lymphatics** to regional cervical lymph nodes. Hematogenous (blood-borne) spread is rare in PTC but is the hallmark of Follicular Thyroid Carcinoma. * **D. Capsulated:** Incorrect. PTC is typically **unencapsulated** and often shows multifocality. Follicular carcinoma and Follicular adenomas are the ones characterized by a distinct capsule. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factor:** Prior exposure to ionizing radiation is the most significant risk factor. * **Microscopic Hallmarks:** * **Orphan Annie Eye nuclei:** Large, pale, empty-appearing nuclei. * **Psammoma bodies:** Laminated calcifications (found in ~50% of cases). * **Nuclear grooves and Pseudo-inclusions.** * **Diagnosis:** Fine Needle Aspiration Cytology (FNAC) is the investigation of choice. Note: FNAC can diagnose PTC but *cannot* distinguish between follicular adenoma and carcinoma. * **Variant:** The **Tall Cell variant** is a more aggressive subtype of PTC.

Question 82: Which type of thyroid cancer has the best prognosis?

A. Papillary (Correct Answer)
B. Medullary
C. Follicular
D. Anaplastic

Explanation: **Explanation:** Thyroid carcinomas vary significantly in their biological behavior and clinical outcomes. The prognosis is generally determined by the degree of differentiation and the rate of local or distant spread. **1. Why Papillary Carcinoma is Correct:** Papillary Thyroid Carcinoma (PTC) is the most common thyroid malignancy (80-85%) and carries the **best prognosis**, with a 10-year survival rate exceeding 90-95%. It is slow-growing, typically spreads via lymphatics (cervical lymphadenopathy), and is highly responsive to standard treatments like total thyroidectomy and radioactive iodine (RAI) therapy. **2. Why the Other Options are Incorrect:** * **Follicular Carcinoma:** While it has a good prognosis (80-90% 10-year survival), it is more aggressive than PTC. It spreads hematogenously (to bone and lungs), making it harder to contain than the lymphatic spread of PTC. * **Medullary Carcinoma:** Arising from parafollicular C-cells, it does not concentrate iodine (making RAI ineffective). It has a moderate prognosis (70-80% 10-year survival) and is often associated with MEN 2 syndromes. * **Anaplastic Carcinoma:** This is one of the most lethal human malignancies. It is undifferentiated, grows rapidly, and is usually resistant to all forms of therapy. The prognosis is dismal, with a median survival of only 6 months. **High-Yield Clinical Pearls for NEET-PG:** * **Order of Prognosis (Best to Worst):** Papillary > Follicular > Medullary > Anaplastic. * **Psammoma bodies:** Characteristic histological finding in Papillary carcinoma. * **Orphan Annie eye nuclei:** Pathognomonic nuclear feature of Papillary carcinoma. * **Most common site of distant metastasis in Follicular CA:** Bone (Osteolytic lesions). * **Tumor Marker for Medullary CA:** Serum Calcitonin.

Question 83: Hypocalcemia in the immediate postoperative period following excision of a parathyroid adenoma is due to which of the following?

A. Stress response
B. Increased uptake by bones (Correct Answer)
C. Persistent hypercalcemia
D. Increased calcitonin secretion

Explanation: **Explanation:** The correct answer is **Increased uptake by bones**, a clinical phenomenon known as **Hungry Bone Syndrome (HBS)**. In patients with primary hyperparathyroidism, chronically high levels of Parathyroid Hormone (PTH) lead to high bone turnover and significant demineralization. Once the parathyroid adenoma is excised, PTH levels drop precipitously. This sudden withdrawal of PTH stops osteoclastic bone resorption, while osteoblastic activity continues or increases. Consequently, the "hungry" bones rapidly sequester calcium, magnesium, and phosphate from the plasma to remineralize the bone matrix, leading to profound postoperative hypocalcemia. **Analysis of Incorrect Options:** * **A. Stress response:** While surgery triggers a metabolic stress response (releasing cortisol and catecholamines), this typically causes hyperglycemia or leukocytosis, not acute hypocalcemia. * **C. Persistent hypercalcemia:** This would occur if the surgery failed (e.g., an ectopic adenoma was missed), which is the opposite of the scenario described. * **D. Increased calcitonin secretion:** Calcitonin is secreted by the parafollicular C-cells of the thyroid. While it lowers calcium, its role in post-parathyroidectomy hypocalcemia is negligible compared to the massive shift of calcium into the bones. **Clinical Pearls for NEET-PG:** * **Risk Factors for HBS:** Large adenomas, very high preoperative PTH/alkaline phosphatase levels, and radiological evidence of bone disease (e.g., Osteitis fibrosa cystica). * **Biochemical Profile of HBS:** Hypocalcemia, **hypophosphatemia**, and often hypomagnesemia. * **Management:** Treatment involves aggressive supplementation with intravenous/oral calcium and Vitamin D (Calcitriol). * **Differential:** Always rule out accidental injury to the remaining normal parathyroid glands (permanent hypoparathyroidism), though HBS is the classic "immediate" cause in bone-involved cases.

Question 84: Which of the following is a true statement regarding follicular cell carcinoma of the thyroid?

A. Hematogenous spread (Correct Answer)
B. Commonly multifocal
C. Readily diagnosed by FNAC
D. Most common carcinoma of the thyroid

Explanation: **Explanation:** **Follicular Thyroid Carcinoma (FTC)** is the second most common thyroid malignancy. The hallmark of FTC is its mode of dissemination and diagnostic criteria. 1. **Why Option A is Correct:** Unlike Papillary Thyroid Carcinoma (PTC), which primarily spreads via the lymphatics, **FTC spreads predominantly via the hematogenous (blood-borne) route.** This leads to distant metastases, most commonly to the **lungs and bones** (often presenting as osteolytic, pulsating lesions). 2. **Why Options B, C, and D are Incorrect:** * **Option B:** FTC is typically **unifocal** and encapsulated. Multifocality is a characteristic feature of Papillary Thyroid Carcinoma. * **Option C:** FTC **cannot** be diagnosed by Fine Needle Aspiration Cytology (FNAC). FNAC can only identify "follicular neoplasms." The diagnosis of carcinoma requires histological evidence of **capsular or vascular invasion**, which necessitates a lobectomy or thyroidectomy for confirmation. * **Option D:** **Papillary Carcinoma** is the most common thyroid cancer (approx. 80-85%), not Follicular Carcinoma (approx. 10%). **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factor:** FTC is more common in areas of **iodine deficiency** (endemic goiter belts). * **Hürthle Cell Carcinoma:** A variant of FTC; it is more aggressive, less likely to take up radioactive iodine, and has a higher rate of lymph node metastasis. * **Staging:** The presence of distant metastasis (M1) is a significant prognostic factor in FTC. * **Treatment:** Total thyroidectomy followed by Radioactive Iodine (RAI) ablation is the standard for tumors >4cm or those with vascular invasion.

Question 85: A patient presents with a thyroid swelling. A radionuclide scan reveals a cold nodule, and an ultrasound shows a non-cystic solid mass. What is the appropriate management for this patient?

A. Lobectomy
B. Hemithyroidectomy (Correct Answer)
C. Eltroxin
D. Radioiodine therapy

Explanation: **Explanation:** The management of a thyroid nodule follows a systematic diagnostic algorithm. In this scenario, the patient has a **cold nodule** on radionuclide scan (indicating decreased iodine uptake) and a **solid mass** on ultrasound. These features are "red flags" as cold, solid nodules have a significantly higher risk of malignancy (approx. 15-20%) compared to hot or cystic nodules. **Why Hemithyroidectomy is correct:** The definitive diagnostic step for a suspicious thyroid nodule is a Fine Needle Aspiration Cytology (FNAC). However, in the context of surgical management options provided for a suspicious solitary nodule, **Hemithyroidectomy** (removal of one lobe and the isthmus) is the initial surgical procedure of choice. It serves both a diagnostic and therapeutic purpose, allowing for a formal histopathological examination to rule out or confirm malignancy (especially follicular carcinoma, which cannot be diagnosed by FNAC alone). **Why other options are incorrect:** * **Lobectomy:** While often used interchangeably in casual conversation, a formal hemithyroidectomy (including the isthmus) is the preferred oncological standard over a simple lobectomy. * **Eltroxin:** This is thyroxine replacement. Suppressive therapy with Eltroxin is no longer the primary management for thyroid nodules and does not address the potential malignancy. * **Radioiodine therapy:** This is used for "hot" (hyperfunctioning) nodules or as adjuvant therapy after total thyroidectomy for differentiated thyroid cancer. It is contraindicated in the initial management of a cold, solid nodule. **NEET-PG High-Yield Pearls:** * **Most common cause of a thyroid nodule:** Colloid goiter. * **Radionuclide Scan:** Most nodules are "cold." Only 5% of "hot" nodules are malignant, whereas ~20% of "cold" nodules are malignant. * **Best Initial Investigation:** Ultrasound. * **Gold Standard Investigation:** FNAC (except for Follicular CA). * **USG signs of malignancy:** Microcalcifications, hypoechogenicity, and irregular margins.

Question 86: Lugol's iodine is given to the patient:

A. Before surgery (Correct Answer)
B. After surgery
C. During surgery
D. Adjuvant therapy

Explanation: **Explanation:** Lugol’s iodine (a solution of 5% iodine and 10% potassium iodide) is classically administered to patients with hyperthyroidism (Graves' disease) **10–14 days before surgery**. **Why it is given before surgery:** The primary goal is to induce the **Wolff-Chaikoff effect**, where high concentrations of iodine acutely inhibit the release of thyroid hormones. More importantly for the surgeon, iodine therapy decreases the **vascularity and friability** of the thyroid gland. It promotes the involution of the gland, making it firmer and less prone to bleeding during dissection, thereby reducing intraoperative complications. **Analysis of Incorrect Options:** * **B. After surgery:** Post-operative iodine is not indicated. Once the gland is removed, the risk of thyroid storm is managed with beta-blockers or steroids if necessary, and the vascularity of the gland is no longer a concern. * **C. During surgery:** The effect of Lugol’s iodine on vascularity takes several days to manifest; intraoperative administration provides no surgical benefit. * **D. Adjuvant therapy:** Adjuvant therapy refers to treatment given after the primary treatment (usually for malignancy). Lugol’s is a preoperative preparation tool, not a long-term cancer treatment. **High-Yield Clinical Pearls for NEET-PG:** * **Dosage:** Usually 3–5 drops three times a day for 10 days. * **Escape Phenomenon:** Lugol’s iodine should not be used for more than 2 weeks, as the thyroid gland "escapes" the inhibitory effect, leading to a rebound surge in hormone synthesis. * **Thyroid Storm:** Lugol’s is also used in the emergency management of thyroid storm to acutely block hormone release (given at least 1 hour after starting antithyroid drugs like PTU). * **Preparation:** Patients must be rendered **euthyroid** using antithyroid drugs (Carbimazole/Methimazole) before starting Lugol’s iodine.

Question 87: What is the treatment for papillary microcarcinoma of the thyroid with lymph node involvement?

A. Radiation
B. Chemotherapy
C. Excision of nodule
D. Total thyroidectomy with modified radical neck dissection (Correct Answer)

Explanation: ### Explanation **Concept:** Papillary Thyroid Microcarcinoma (PTMC) is defined as a papillary thyroid cancer measuring **≤1 cm** in its greatest dimension. While many PTMCs are indolent and can be managed with lobectomy or even active surveillance, the presence of **lymph node metastasis** (N1 disease) automatically upgrades the surgical requirement. **Why Option D is Correct:** In the presence of clinically evident or biopsy-proven lymph node involvement, the standard of care is a **Total Thyroidectomy** combined with a **Modified Radical Neck Dissection (MRND)** or selective neck dissection (Levels II-V). Total thyroidectomy is necessary to facilitate subsequent Radioiodine (RAI) ablation, which is indicated in node-positive disease to reduce recurrence risk. **Why Other Options are Incorrect:** * **A & B (Radiation/Chemotherapy):** Differentiated thyroid cancers (Papillary and Follicular) are generally resistant to chemotherapy and external beam radiation. These are reserved for palliative care or anaplastic variants. * **C (Excision of Nodule):** Simple nodulectomy (enucleation) is never appropriate for thyroid malignancy as it carries a high risk of recurrence and violates oncological principles. Even for low-risk PTMC without nodes, a hemithyroidectomy (lobectomy) is the minimum requirement. **High-Yield Clinical Pearls for NEET-PG:** * **Definition:** PTMC = Size ≤10 mm. * **Prognosis:** Excellent, with 10-year survival rates >99%. * **Indications for Total Thyroidectomy in PTMC:** Lymph node metastasis, distant metastasis, history of radiation exposure, or bilateral disease. * **Staging Note:** In patients <55 years, the presence of lymph node metastasis (Stage I) does not change the excellent prognosis, but it does dictate more aggressive surgical management.

Question 88: Which type of thyroid malignancy is most commonly associated with prior radiation exposure?

A. Follicular carcinoma
B. Papillary carcinoma (Correct Answer)
C. Medullary carcinoma
D. Anaplastic carcinoma

Explanation: **Explanation:** **Papillary Thyroid Carcinoma (PTC)** is the most common thyroid malignancy overall and has the strongest association with prior exposure to ionizing radiation (e.g., childhood neck irradiation or nuclear accidents like Chernobyl). Radiation induces genetic rearrangements, most notably the **RET/PTC rearrangement**, which plays a key role in the pathogenesis of radiation-induced PTC. **Analysis of Options:** * **Follicular Carcinoma (Option A):** While it can occur after radiation, it is more strongly associated with **iodine deficiency**. It typically spreads hematogenously (to bone and lungs). * **Medullary Carcinoma (Option C):** This arises from parafollicular C-cells and is primarily associated with **RET proto-oncogene mutations** (germline in MEN 2A/2B or sporadic). It is not linked to radiation exposure. * **Anaplastic Carcinoma (Option D):** This is an undifferentiated, highly aggressive tumor seen in the elderly. While it can arise from pre-existing well-differentiated cancers, radiation is not its primary risk factor. **High-Yield Clinical Pearls for NEET-PG:** * **Most common** thyroid cancer: Papillary Carcinoma (>80%). * **Characteristic Histology:** Orphan Annie eye nuclei (empty-appearing), Psammoma bodies (calcifications), and nuclear grooves. * **Route of Spread:** Papillary spreads via **lymphatics** (Level VI nodes first); Follicular spreads via **blood**. * **Prognosis:** Papillary has an excellent prognosis; Anaplastic has the worst. * **Investigation of Choice:** FNAC (Note: FNAC cannot distinguish between Follicular Adenoma and Carcinoma; biopsy is needed for the latter to show capsular/vascular invasion).

Question 89: A patient presents with neck swelling and respiratory distress a few hours after thyroidectomy. What is the immediate next management step?

A. Immediate surgical exploration (Correct Answer)
B. Tracheostomy
C. Observe the patient
D. Administer oxygen via mask

Explanation: **Explanation:** The clinical presentation of sudden neck swelling and respiratory distress following a thyroidectomy is a surgical emergency, most likely due to a **tension hematoma**. **1. Why Option A is Correct:** The primary cause of distress is a rapidly expanding hematoma in the subplatysmal space. This hematoma exerts direct pressure on the trachea and, more importantly, causes **venous and lymphatic obstruction**, leading to laryngeal edema. The immediate priority is to **decompress the neck**. This is done by opening the surgical incision (removing sutures/clips) at the bedside to evacuate the clot and relieve the pressure. This must be followed by immediate transfer to the operating room for formal surgical exploration and hemostasis. **2. Why Other Options are Incorrect:** * **B. Tracheostomy:** This is technically difficult and time-consuming in a patient with a distorted neck anatomy due to a hematoma. Decompression must precede any airway intervention. * **C. Observe the patient:** This is fatal. Post-thyroidectomy hematomas can lead to rapid airway occlusion and respiratory arrest. * **D. Administer oxygen:** While supportive, oxygen does not address the mechanical obstruction. Without decompression, the airway will continue to narrow. **Clinical Pearls for NEET-PG:** * **Most common cause:** Slippage of a ligature on the **Superior Thyroid Artery**. * **Timing:** Usually occurs within the first 6–24 hours post-surgery. * **Management Sequence:** 1. Bedside decompression (opening the wound) → 2. Intubation (if needed) → 3. Formal exploration in the OR. * **Stridor** is a late and ominous sign of airway compromise in these patients.

Question 90: Which of the following is a common clinical presentation of a retrosternal goiter?

A. Causes stridor (Correct Answer)
B. Obtains its blood supply from thoracic vessels
C. Is characteristically malignant
D. Must be removed by thoracotomy

Explanation: ### Explanation **1. Why Option A is Correct:** A retrosternal (substernal) goiter is defined as a thyroid enlargement where more than 50% of the mass is below the thoracic inlet. Because the thoracic inlet is a rigid, bony space, any significant enlargement leads to **compression of the trachea**. This results in respiratory symptoms, most commonly **stridor**, dyspnea, or a choking sensation, especially when the patient lies supine or raises their arms (Pemberton’s sign). **2. Why the Other Options are Incorrect:** * **Option B:** Most retrosternal goiters are "secondary," meaning they originate in the neck and descend into the chest. Consequently, they retain their **superior and inferior thyroid arteries** (branches of the external carotid and thyrocervical trunk, respectively) as their primary blood supply, not thoracic vessels. * **Option C:** The majority of retrosternal goiters are **benign multinodular goiters**. While the risk of malignancy exists (approx. 5–10%), it is not "characteristically" malignant. * **Option D:** Over 90% of retrosternal goiters can be safely removed via a **standard cervical (trans-cervical) incision**. Thoracotomy or sternotomy is rarely required (usually <5% of cases) and is reserved for primary intrathoracic goiters, recurrent cases, or massive posterior mediastinal extensions. **Clinical Pearls for NEET-PG:** * **Pemberton’s Sign:** Facial flushing, cyanosis, and inspiratory stridor upon raising both arms above the head; indicates superior vena cava (SVC) syndrome or tracheal compression at the thoracic inlet. * **Imaging Gold Standard:** Contrast-Enhanced CT (CECT) is the investigation of choice to assess the extent of the goiter and its relationship to great vessels. * **Primary vs. Secondary:** Primary intrathoracic goiters (ectopic) are rare (<1%) and derive blood supply from internal mammary or intercostal vessels; these *do* require a thoracic approach.

Practice by Chapter

Thyroid Nodules

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Thyroid Cancer

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Graves' Disease

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Thyroiditis

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Primary Hyperparathyroidism

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Secondary and Tertiary Hyperparathyroidism

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Adrenal Cortical Tumors

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Pheochromocytoma

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Adrenal Incidentalomas

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Multiple Endocrine Neoplasia

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Neuroendocrine Tumors

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Intraoperative Monitoring in Endocrine Surgery

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