Endocrine Surgery — MCQs

Endocrine Surgery Indian Medical PG Practice Questions and MCQs

Question 131: Which of the following statements is NOT TRUE regarding papillary carcinoma of the thyroid?

A. Can be reliably diagnosed using Fine Needle Aspiration Cytology (FNAC).
B. Is always unifocal. (Correct Answer)
C. Typically spreads to the cervical lymph nodes.
D. Requires a total thyroidectomy for large tumors.

Explanation: **Explanation:** **1. Why Option B is the Correct Answer (The False Statement):** Papillary Thyroid Carcinoma (PTC) is characterized by its **multifocality**. In approximately 20–80% of cases, multiple foci of the tumor are found within the same lobe or the contralateral lobe. This occurs due to intraglandular lymphatic spread rather than independent primary origins. Therefore, the statement that it is "always unifocal" is medically incorrect. **2. Analysis of Other Options:** * **Option A:** FNAC is the gold standard for diagnosing PTC. It reliably identifies characteristic nuclear features such as **Orphan Annie eye nuclei**, intranuclear inclusions, and nuclear grooves. Unlike follicular carcinoma, PTC does not require vascular or capsular invasion for diagnosis. * **Option C:** PTC is a "lymphophile" tumor. Its primary mode of metastasis is via the **lymphatics** to the central (Level VI) and lateral cervical lymph nodes. * **Option D:** While microcarcinomas (<1 cm) may be managed with lobectomy, the standard treatment for tumors >4 cm, or those with extrathyroidal extension/metastasis, is **Total Thyroidectomy** to facilitate postoperative Radioiodine (RAI) ablation and monitoring of Thyroglobulin levels. **Clinical Pearls for NEET-PG:** * **Most common** type of thyroid malignancy (85%). * **Psammoma bodies** (laminated calcifications) are seen in 50% of cases. * **Prognosis:** Excellent, with a 10-year survival rate >90%. * **Risk Factor:** Prior exposure to ionizing radiation. * **Genetic markers:** *BRAF* mutation (most common) and *RET/PTC* rearrangements.

Question 132: Lymph node metastasis is least commonly seen with which of the following types of thyroid carcinoma?

A. Papillary Carcinoma of Thyroid
B. Medullary Carcinoma of Thyroid
C. Follicular Carcinoma of Thyroid (Correct Answer)
D. All of the above

Explanation: ### Explanation The correct answer is **Follicular Carcinoma of Thyroid (FTC)**. The fundamental concept here is the **mode of spread** characteristic of different thyroid malignancies. **1. Why Follicular Carcinoma is the correct answer:** Follicular carcinoma is characterized by **hematogenous spread** (via the bloodstream) rather than lymphatic spread. It has a high propensity for angioinvasion, leading to distant metastases in the bones (osteolytic lesions) and lungs. Lymph node involvement in FTC is rare, occurring in less than 10% of cases. **2. Why the other options are incorrect:** * **Papillary Carcinoma (PTC):** This is the most common thyroid cancer and is notorious for **lymphatic spread**. Cervical lymph node involvement is present in approximately 50–70% of cases at the time of diagnosis. * **Medullary Carcinoma (MTC):** Arising from parafollicular C-cells, MTC spreads early to both local and mediastinal lymph nodes. Lymph node metastasis is a hallmark of this condition and significantly impacts prognosis. **Clinical Pearls for NEET-PG:** * **Route of Spread:** Papillary = Lymphatic; Follicular = Hematogenous; Medullary = Both; Anaplastic = Local invasion. * **Diagnosis:** FTC cannot be diagnosed by FNAC because FNAC cannot distinguish between a follicular adenoma and carcinoma. Diagnosis requires histological evidence of **capsular or vascular invasion**. * **Orphan Annie Eyes:** Characteristic nuclear feature of Papillary Carcinoma. * **Psammoma Bodies:** Frequently seen in Papillary Carcinoma, rarely in others. * **Amyloid Stroma:** Pathognomonic for Medullary Carcinoma (stains with Congo Red).

Question 133: What is the appropriate surgical approach for thyroidectomy to remove a thyroid carcinoma with retrosternal extension?

A. Cervical
B. Thoracic
C. Combined cervical and thoracic (Correct Answer)
D. Thoracoscopic

Explanation: The surgical management of retrosternal goiters or carcinomas depends on the extent of the lesion and its pathology. **Explanation of the Correct Answer:** While most benign retrosternal goiters (90-95%) can be delivered through a standard cervical incision, **thyroid carcinoma with retrosternal extension** often requires a **combined cervical and thoracic approach** (Option C). This is because malignancy often involves local invasion into mediastinal structures or requires a formal mediastinal lymph node dissection. A sternotomy or thoracotomy provides the necessary exposure to ensure oncological clearance, control major vessels, and safely visualize the recurrent laryngeal nerve in the chest. **Analysis of Incorrect Options:** * **A. Cervical:** This is the standard approach for simple retrosternal goiters. However, for carcinoma, it offers inadequate visualization of the lower poles and mediastinal lymph nodes, increasing the risk of incomplete resection or uncontrollable hemorrhage. * **B. Thoracic:** A purely thoracic approach is insufficient as the superior vascular pedicles (superior thyroid artery) and the upper pole of the thyroid must be addressed via the neck. * **D. Thoracoscopic:** While used in specialized centers for benign cases, it is not the standard of care for invasive thyroid carcinoma requiring complex reconstruction or extensive lymphadenectomy. **High-Yield Clinical Pearls for NEET-PG:** * **Definition:** A goiter is "retrosternal" if >50% of the mass is below the thoracic inlet. * **Imaging:** Contrast-Enhanced CT (CECT) is the gold standard for preoperative planning of retrosternal extension. * **Indications for Sternotomy:** Malignancy, primary mediastinal goiter (ectopic), previous neck surgery, or extension beyond the level of the aortic arch/carina. * **Most common type:** Most retrosternal goiters are "secondary" (arising from the neck and descending). "Primary" mediastinal goiters (arising from ectopic tissue) are rare (<1%) and usually require a thoracic approach.

Question 134: Which of the following statements regarding parathyroid glands is true?

A. Upper parathyroid glands are located superior to the junction of the inferior thyroid artery and the recurrent laryngeal nerve (RLN).
B. The most common location for ectopic parathyroid glands is paraesophageal.
C. Lower parathyroid glands are situated anterior to the recurrent laryngeal nerve (RLN).
D. All of the above. (Correct Answer)

Explanation: This question tests the surgical anatomy of the parathyroid glands, which is a high-yield topic for NEET-PG due to its clinical importance in thyroid and parathyroid surgeries. ### **Explanation of Options** * **Option A:** The **superior (upper) parathyroid glands** are embryologically derived from the 4th branchial pouch. They are relatively constant in position and are typically located **superior** to the intersection of the inferior thyroid artery (ITA) and the recurrent laryngeal nerve (RLN), usually on the posterior aspect of the upper two-thirds of the thyroid lobe. * **Option B:** While parathyroid glands can be found anywhere from the carotid bifurcation to the mediastinum, the **most common ectopic site** for a parathyroid adenoma is the **paraesophageal** region (posterior to the esophagus or in the tracheoesophageal groove). * **Option C:** The **inferior (lower) parathyroid glands** are derived from the 3rd branchial pouch (along with the thymus). Because they migrate further, their position is more variable. However, when found in their typical location near the lower pole of the thyroid, they are almost always situated **anterior (ventral)** to the recurrent laryngeal nerve. Since all three anatomical statements are surgically accurate, **Option D (All of the above)** is the correct answer. ### **High-Yield Clinical Pearls for NEET-PG** * **The "Rule of RLN":** Superior glands are **posterior/deep** to the RLN; Inferior glands are **anterior/superficial** to the RLN. * **Blood Supply:** Both superior and inferior glands are primarily supplied by the **inferior thyroid artery** (ITA). * **Ectopic Lower Glands:** Because they migrate with the thymus, ectopic lower glands are frequently found in the **anterior mediastinum/thymus**. * **Most common cause of Primary Hyperparathyroidism:** Solitary Adenoma (85%).

Question 135: Which of the following statements regarding papillary thyroid carcinoma are true?

A. Seventy to 80% of new cases of thyroid carcinoma in the United States are of the papillary type.
B. Total ipsilateral lobectomy and isthmus resection are adequate therapy for minimal thyroid carcinoma.
C. Microscopic evidence of multicentric disease is present in 70% to 80% of cases.
D. All of the above. (Correct Answer)

Explanation: **Explanation:** Papillary Thyroid Carcinoma (PTC) is the most common malignancy of the thyroid gland, characterized by its indolent course and excellent prognosis. This question tests fundamental epidemiological and surgical principles of PTC. * **Option A (Epidemiology):** PTC accounts for approximately **70-80%** of all thyroid cancers in iodine-sufficient regions like the United States. It is more common in females and often associated with radiation exposure. * **Option B (Surgical Management):** For "minimal" or "micro-papillary" carcinoma (defined as a tumor **<1 cm** confined to the thyroid without extrathyroidal extension or lymph node involvement), a **unilateral lobectomy and isthmus resection** is considered oncologically adequate. This approach minimizes surgical morbidity (recurrent laryngeal nerve injury or hypoparathyroidism) while maintaining excellent survival rates. * **Option C (Pathology):** PTC is notoriously **multicentric**. While clinically apparent multifocality is lower, microscopic examination of the contralateral lobe reveals foci of tumor in **70-80%** of cases. This high rate of multicentricity is a primary argument used by surgeons who advocate for total thyroidectomy in larger tumors (>1-4 cm). Since all three statements are accurate descriptions of the disease's behavior and management, **Option D** is the correct answer. **High-Yield Clinical Pearls for NEET-PG:** * **Hallmark Histology:** Orphan Annie eye nuclei (empty-appearing), Psammoma bodies (laminated calcifications), and nuclear grooves. * **Spread:** Primarily via **lymphatics** (cervical lymphadenopathy is common). * **Prognosis:** Excellent; 10-year survival is >90%. * **Risk Factor:** Childhood neck irradiation is the most significant risk factor. * **Molecular Marker:** **BRAF V600E** mutation is the most common genetic alteration and is associated with a higher risk of recurrence.

Question 136: Which of the following is NOT a feature of de Quervain's thyroiditis?

A. Autoimmune in etiology (Correct Answer)
B. Thyroid-stimulating immunoglobulin (TSI) mediated
C. Tends to regress spontaneously
D. Painful and associated with enlargement of the thyroid

Explanation: **Explanation:** **De Quervain’s Thyroiditis** (also known as Subacute Granulomatous Thyroiditis) is primarily a **post-viral inflammatory condition**, not an autoimmune one. It typically follows an upper respiratory tract infection (e.g., Coxsackie, Mumps, or Adenovirus). 1. **Why Option A is correct:** De Quervain’s is triggered by viral pathogens that cause follicular destruction. Unlike Hashimoto’s or Graves' disease, it is **not autoimmune** in etiology. While it is associated with HLA-B35, the underlying mechanism is inflammatory/infectious. 2. **Why Option B is incorrect (as a feature):** This is a slightly tricky distractor. While the question asks for what is *NOT* a feature, Option A is the most definitive "non-feature." However, **TSI** is specifically seen in Graves' disease. In De Quervain's, you see a transient hyperthyroid phase due to the "leakage" of preformed hormones, not due to TSI stimulation. 3. **Why Option C is a feature:** The disease is characteristically **self-limiting**. Most patients return to a euthyroid state within weeks to months after passing through transient hyperthyroid and hypothyroid phases. 4. **Why Option D is a feature:** The hallmark clinical presentation is a **painful, tender thyroid gland** (often radiating to the jaw or ear) accompanied by fever and firm thyroid enlargement. **High-Yield Clinical Pearls for NEET-PG:** * **Pathology:** Characterized by **multinucleated giant cells** and granulomas. * **Investigation:** ESR is markedly **elevated** (often >50-100 mm/hr). * **Radioiodine Uptake (RAIU):** Characteristically **low/depressed** during the thyrotoxic phase (due to follicular damage). * **Treatment:** NSAIDs for pain; Steroids if severe; Propropanol for symptomatic thyrotoxicosis. Antithyroid drugs (PTU/Methimazole) are **not** indicated.

Question 137: What is the indication for surgery in a case of adrenal incidentaloma?

A. >2cm
B. >3cm
C. >4cm (Correct Answer)
D. >5cm

Explanation: **Explanation:** The management of an adrenal incidentaloma—a clinically unsuspected adrenal mass discovered during imaging for unrelated reasons—is based on two primary concerns: **hormonal hypersecretion** and **malignant potential**. **Why >4cm is the correct answer:** The size of the mass is the most reliable predictor of adrenocortical carcinoma (ACC). Studies show that the risk of malignancy increases significantly as the diameter exceeds 4 cm. While the risk is <2% for masses <4 cm, it rises to approximately 6% for masses between 4–6 cm and up to 25% for those >6 cm. Therefore, current guidelines (including AACE/AAES) recommend surgical resection for any incidentaloma **>4 cm** in size, even if non-functional, provided the patient is a good surgical candidate. **Analysis of Incorrect Options:** * **A (>2cm) & B (>3cm):** These thresholds are too low. Operating at these sizes would lead to unnecessary surgeries for benign adenomas, which are highly prevalent in the general population. * **D (>5cm):** While a 5 cm mass certainly requires surgery, the standard clinical "cutoff" for intervention starts at 4 cm to ensure early detection of potentially curable malignancy. **High-Yield Clinical Pearls for NEET-PG:** 1. **Workup:** Every incidentaloma must undergo biochemical screening for **Pheochromocytoma** (plasma/urinary metanephrines), **Cushing’s Syndrome** (1mg overnight dexamethasone suppression test), and **Primary Aldosteronism** (if hypertensive). 2. **Imaging Characteristics:** A mass with **low attenuation (<10 Hounsfield Units)** on non-contrast CT suggests high lipid content, characteristic of a benign adenoma. 3. **Biopsy Rule:** Fine-needle aspiration (FNA) is **never** used to distinguish benign from malignant primary adrenal tumors. It is only indicated if a metastasis from another primary site is suspected, and only *after* pheochromocytoma has been biochemically ruled out.

Question 138: What is the investigation of choice in parathyroid pathology?

A. CT Scan
B. Gallium scan
C. Thallium scan
D. Tc – Thallium subtraction scan (Correct Answer)

Explanation: **Explanation:** The primary challenge in imaging parathyroid pathology (like adenomas or hyperplasia) is their small size and proximity to the thyroid gland. The **Tc-Thallium subtraction scan** is a dual-isotope technique used to isolate parathyroid tissue. **Why it is correct:** * **Thallium-201** is taken up by both the thyroid and the parathyroid glands. * **Technetium-99m (pertechnetate)** is taken up only by the thyroid gland. * By digitally subtracting the Technetium image from the Thallium image, the thyroid signal is removed, leaving only the abnormal parathyroid tissue visible. **Why other options are incorrect:** * **CT Scan:** While useful for ectopic parathyroid glands in the mediastinum, it is not the first-line "investigation of choice" due to low sensitivity for small cervical adenomas and radiation exposure. * **Gallium Scan:** This is primarily used for detecting inflammation, infections, or certain malignancies (like lymphoma); it has no role in parathyroid imaging. * **Thallium Scan (alone):** Thallium is non-specific. Without subtraction, it is impossible to distinguish a parathyroid adenoma from the surrounding thyroid tissue. **High-Yield Clinical Pearls for NEET-PG:** 1. **Current Gold Standard:** While the subtraction scan is the classic answer, the **99mTc-Sestamibi scan** (specifically SPECT/CT) is now the modern investigation of choice due to better resolution. 2. **Initial Screening:** Neck Ultrasound (USG) is often the first imaging modality performed due to its low cost and lack of radiation. 3. **Definitive Diagnosis:** Diagnosis of hyperparathyroidism is **biochemical** (elevated Calcium and PTH); imaging is only for **pre-operative localization**. 4. **4D-CT:** Increasingly used for re-operative cases or when Sestamibi is negative.

Question 139: What is the indication for surgery in a case of adrenal incidentaloma?

A. Size > 5 cm
B. Bilateral adrenal metastasis
C. Functional tumor
D. All of the above (Correct Answer)

Explanation: An **adrenal incidentaloma** is an adrenal mass (≥1 cm) discovered during imaging for reasons unrelated to suspected adrenal disease. The management goal is to identify lesions that are either **malignant** or **hormonally active**. ### **Explanation of Options:** * **Size > 4–6 cm (Option A):** Size is the most reliable predictor of malignancy. While the exact threshold varies by guideline, a diameter **>4 cm** (or >5 cm in some protocols) significantly increases the risk of adrenocortical carcinoma. Large size is a primary surgical indication regardless of hormonal status. * **Bilateral Adrenal Metastasis (Option B):** While most metastases are managed medically, surgery (adrenalectomy) is indicated for **isolated adrenal metastasis** (especially from lung or renal cell carcinoma) if the primary tumor is controlled and there is no other systemic spread. * **Functional Tumor (Option C):** Any incidentaloma that shows biochemical evidence of hormone overproduction—such as **Pheochromocytoma**, **Cushing’s syndrome** (autonomous cortisol secretion), or **Conn’s syndrome** (Primary Aldosteronism)—requires surgical excision to prevent metabolic and cardiovascular complications. ### **High-Yield Clinical Pearls for NEET-PG:** 1. **Initial Workup:** Every incidentaloma must undergo a **24-hour urinary metanephrine** test (to rule out pheochromocytoma) and a **1 mg Overnight Dexamethasone Suppression Test** (to rule out Cushing’s). 2. **Imaging Characteristics:** A "benign" lesion on CT typically has **low Hounsfield Units (HU <10)** due to high lipid content and rapid contrast washout (>60% at 10-15 mins). 3. **Biopsy Contraindication:** Never perform a Fine Needle Aspiration (FNA) until **Pheochromocytoma is ruled out**, as it can trigger a fatal hypertensive crisis. 4. **Follow-up:** Non-surgical lesions <4 cm should be monitored with repeat imaging at 6–12 months.

Question 140: A 45-year-old male presents with a 4x4 cm, mobile right solitary thyroid nodule of 5 months duration. The patient is euthyroid. Which of the following statements about its management is FALSE?

A. A cold nodule on thyroid scan is diagnostic of malignancy. (Correct Answer)
B. Fine Needle Aspiration Cytology (FNAC) is the investigation of choice.
C. The patient should undergo hemithyroidectomy if the FNAC report is inconclusive.
D. Indirect laryngoscopy should be done in the preoperative period to assess vocal cord mobility.

Explanation: ### Explanation **1. Why Option A is False (The Correct Answer):** A "cold nodule" on a radionuclide thyroid scan indicates a region of decreased uptake compared to the surrounding normal tissue. While it is true that **85% of thyroid malignancies present as cold nodules**, the converse is not true: only about **15-20% of cold nodules are actually malignant**. Most cold nodules are benign conditions such as colloid cysts, adenomas, or thyroiditis. Therefore, a cold scan is **suspicious but not diagnostic** of malignancy. **2. Analysis of Other Options:** * **Option B:** **FNAC is the investigation of choice (IOC)** for any solitary thyroid nodule >1 cm. It has high sensitivity and specificity for diagnosing papillary carcinoma, medullary carcinoma, and anaplastic carcinoma. * **Option C:** If FNAC is inconclusive (Bethesda Category I or III/IV), and the nodule is clinically significant (like this 4 cm nodule), a **diagnostic hemithyroidectomy** is indicated to obtain a definitive histopathological diagnosis. * **Option D:** **Indirect Laryngoscopy (IDL)** or fiberoptic laryngoscopy is mandatory preoperatively to document vocal cord mobility. This is crucial for medicolegal reasons and to identify asymptomatic vocal cord palsy before surgery. ### High-Yield Clinical Pearls for NEET-PG: * **Hot Nodule:** Increased uptake; usually represents a toxic adenoma. Risk of malignancy is very low (<1%). * **Warm Nodule:** Uptake equal to normal tissue; risk of malignancy is ~5-10%. * **Best Initial Test:** Serum TSH. If TSH is normal/high, proceed to FNAC. If TSH is low, proceed to Thyroid Scan. * **Gold Standard for Diagnosis:** Histopathology (post-surgery), as FNAC cannot distinguish between follicular adenoma and follicular carcinoma (requires evidence of capsular or vascular invasion).

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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