Endocrine Surgery — MCQs

Endocrine Surgery Indian Medical PG Practice Questions and MCQs

Question 91: A 45-year-old patient presents with thyroid swelling and a lymph node in the neck. On aspiration, amyloid material was found. What is the management?

A. Total thyroidectomy with neck dissection (Correct Answer)
B. Hemithyroidectomy
C. Hemithyroidectomy with neck dissection
D. Total thyroidectomy with neck irradiation

Explanation: **Explanation:** The presence of **amyloid material** on fine-needle aspiration (FNA) of a thyroid swelling is pathognomonic for **Medullary Thyroid Carcinoma (MTC)**. MTC arises from the parafollicular C-cells, which secrete calcitonin; the deposition of pro-calcitonin results in the characteristic amyloid stroma. **Why Option A is Correct:** MTC is typically multicentric and does not respond to radioactive iodine or TSH suppression. Therefore, the standard surgical treatment is a **Total Thyroidectomy**. Furthermore, MTC has a high propensity for early lymphatic spread. The presence of a palpable lymph node in this patient necessitates a **therapeutic neck dissection** (Central and Selective Lateral Neck Dissection) to achieve locoregional control. **Why Other Options are Incorrect:** * **Options B & C (Hemithyroidectomy):** MTC is often bilateral (especially in familial/MEN 2 syndromes) and aggressive. Hemithyroidectomy is oncologically inadequate and carries a high risk of recurrence. * **Option D (Neck Irradiation):** MTC is relatively radioresistant. Surgery is the primary curative modality. External beam radiation is reserved only for palliative care or unresectable local disease, not as a primary substitute for neck dissection. **High-Yield Clinical Pearls for NEET-PG:** * **Tumor Marker:** Calcitonin (for diagnosis/follow-up) and CEA (for prognosis). * **Genetic Screening:** All MTC patients must be screened for **RET proto-oncogene** mutations and associated MEN 2A/2B syndromes (pheochromocytoma and hyperparathyroidism). * **Staining:** Amyloid shows **apple-green birefringence** under polarized light with Congo Red stain. * **Prophylaxis:** In RET-positive relatives, prophylactic total thyroidectomy is indicated.

Question 92: A 55-year-old male patient underwent cholecystectomy for gallstone calculus. During surgery, the patient's pulse was irregularly irregular, 160/min, BP = 80/50 mm of Hg, and temperature was 40°C. On examination, a swelling in the neck was found. What is the most likely diagnosis?

A. Thyroid storm (Correct Answer)
B. Myocardial infarction
C. Arrhythmia
D. Stridor

Explanation: **Explanation:** The clinical presentation described—**hyperpyrexia (40°C)**, **tachyarrhythmia** (irregularly irregular pulse of 160/min, likely Atrial Fibrillation), and **hemodynamic instability** (BP 80/50 mmHg) in the presence of a **neck swelling** (goiter)—is a classic triad for **Thyroid Storm**. Thyroid storm is a life-threatening exacerbation of hyperthyroidism. In this case, the stress of surgery (cholecystectomy) acted as the precipitating factor. The "irregularly irregular" pulse indicates Atrial Fibrillation, a common complication of thyrotoxicosis due to increased sensitivity to catecholamines. **Why other options are incorrect:** * **Myocardial Infarction:** While it can cause hypotension and tachycardia, it does not typically present with high-grade fever (40°C) or a neck swelling. * **Arrhythmia:** This is a *finding* (symptom) in this case, not the primary diagnosis. The arrhythmia is secondary to the underlying thyrotoxic state. * **Stridor:** This is a physical sign of upper airway obstruction (often post-thyroidectomy due to nerve injury or hematoma) and does not explain the systemic symptoms of fever and hypotension. **NEET-PG High-Yield Pearls:** * **Precipitating factors:** Infection, trauma, surgery (especially in undiagnosed hyperthyroid patients), or DKA. * **Burch-Wartofsky Point Scale:** Used to diagnose Thyroid Storm based on thermoregulatory dysfunction, CNS effects, GI-hepatic dysfunction, and cardiovascular status. * **Management (The "P"s):** **P**ropylthiouracil (blocks synthesis and peripheral T4 to T3 conversion), **P**ropanolol (beta-blockade), **P**otassium Iodide (Lugol’s iodine to block hormone release), and **P**rednisolone (steroids).

Question 93: Thoracic extension of cervical goitre is usually approached through which route?

A. Neck (Correct Answer)
B. Chest
C. Combined cervico-thoracic route
D. Thoracoscopic

Explanation: **Explanation:** The correct answer is **A. Neck**. **Why the Neck approach is correct:** The vast majority (over 90-95%) of retrosternal or substernal goitres are **secondary goitres**. This means they originate in the neck from the thyroid gland and descend into the mediastinum due to gravity, negative intrathoracic pressure, and the constraints of the pretracheal fascia. Crucially, these goitres retain their **blood supply from the neck** (primarily the superior and inferior thyroid arteries). Because the vascular pedicle is accessible from above, they can almost always be safely delivered and removed through a standard Kocher’s transverse collar incision in the neck. **Why other options are incorrect:** * **B & D (Chest/Thoracoscopic):** These routes are rarely required because the blood supply does not originate from the thoracic vessels. Approaching from the chest first risks uncontrollable hemorrhage if the cervical vessels are not secured. * **C (Combined cervico-thoracic):** A sternotomy or thoracotomy is indicated in only 2-5% of cases. These include **primary intrathoracic goitres** (ectopic thyroid tissue with blood supply from internal mammary or intercostal vessels), massive goitres wider than the thoracic inlet ("dumbbell" shape), malignancy invading thoracic structures, or failed previous cervical attempts. **High-Yield Clinical Pearls for NEET-PG:** * **Definition:** A goitre is "retrosternal" if more than 50% of the thyroid is below the suprasternal notch. * **Pemberton’s Sign:** Facial congestion and inspiratory stridor upon raising both arms (due to thoracic inlet obstruction); a classic finding in retrosternal goitre. * **Most common site:** Anterior mediastinum (80-90%). * **Key Surgical Tip:** If the goitre is stuck, "digital dissection" and delivery of the lower pole into the neck is the standard maneuver. Sternotomy is the exception, not the rule.

Question 94: A 50-year-old healthy man presents with a 2 cm papillary thyroid carcinoma in the right lobe, diagnosed on FNAC. What is the recommended treatment?

A. Right lobectomy and isthmusectomy
B. Right lobectomy
C. Excisional biopsy with frozen section analysis
D. Total right lobectomy and subtotal left lobectomy (Correct Answer)

Explanation: **Explanation:** The management of Papillary Thyroid Carcinoma (PTC) is guided by the size of the lesion and the patient's risk profile. For a **2 cm tumor** in a 50-year-old patient, the traditional surgical standard (often tested in NEET-PG based on classic surgical teaching) is a **Near-total thyroidectomy** or **Total right lobectomy and subtotal left lobectomy**. 1. **Why Option D is Correct:** In tumors between 1 cm and 4 cm, a near-total thyroidectomy (leaving <1g of tissue near the recurrent laryngeal nerve) or total thyroidectomy is preferred over simple lobectomy. This approach facilitates the use of **Radioactive Iodine (RAI) ablation** post-operatively to treat occult microscopic disease and allows for more accurate monitoring of **Serum Thyroglobulin** as a tumor marker for recurrence. 2. **Why other options are wrong:** * **Options A & B:** While recent ATA guidelines suggest a unilateral lobectomy may be sufficient for low-risk 1–4 cm tumors, standard exam patterns still favor more extensive surgery for tumors >1 cm in patients >45 years to reduce recurrence rates. * **Option C:** FNAC has already provided a diagnosis of PTC (Bethesda VI). Excisional biopsy is not a standard diagnostic or therapeutic step for thyroid nodules; definitive resection is required. **Clinical Pearls for NEET-PG:** * **Size Criteria:** If PTC is <1 cm (Microcarcinoma) and unifocal, **Hemithyroidectomy** is sufficient. If >4 cm or showing extrathyroidal extension, **Total Thyroidectomy** is mandatory. * **Most Common:** PTC is the most common thyroid malignancy and has the best prognosis. * **Spread:** PTC primarily spreads via **lymphatics** (Level VI nodes are the first station). * **Psammoma bodies:** A classic histological hallmark of PTC.

Question 95: What is the commonest presenting complaint of medullary carcinoma of the thyroid?

A. Diarrhea (Correct Answer)
B. Dysphagia
C. Hoarseness
D. Flushing

Explanation: **Explanation:** Medullary Carcinoma of the Thyroid (MCT) arises from the **parafollicular C-cells**, which are neuroendocrine cells derived from the neural crest. These cells characteristically secrete **Calcitonin**, which serves as a highly sensitive tumor marker. **Why Diarrhea is the correct answer:** Diarrhea is the most common systemic symptom of MCT, occurring in approximately 30% of patients. It is typically a **secretory diarrhea** caused by the high levels of circulating calcitonin, prostaglandins, and serotonin secreted by the tumor. These substances increase intestinal motility and alter electrolyte transport. In advanced or metastatic cases, diarrhea is often the most debilitating constitutional symptom. **Analysis of Incorrect Options:** * **B. Dysphagia & C. Hoarseness:** These are symptoms of local invasion or compression (esophageal compression and recurrent laryngeal nerve palsy, respectively). While they occur in advanced thyroid cancers, they are less specific to the neuroendocrine nature of MCT compared to diarrhea. * **D. Flushing:** While flushing is a known systemic symptom of MCT (often associated with the secretion of substance P or calcitonin gene-related peptide), it is clinically **less common** than diarrhea. **High-Yield Clinical Pearls for NEET-PG:** * **Tumor Marker:** Calcitonin (for diagnosis and follow-up) and CEA (for prognosis). * **Histology:** Characterized by **Amyloid stroma** (stained with Congo Red, showing apple-green birefringence). * **Genetics:** 75% are sporadic; 25% are familial (associated with **MEN 2A and 2B** syndromes due to **RET proto-oncogene** mutations). * **Treatment of Choice:** Total thyroidectomy with central compartment neck dissection. * **Prophylaxis:** In MEN 2A/2B, prophylactic thyroidectomy is recommended based on the specific RET mutation codon.

Question 96: What is the characteristic feature of medullary carcinoma?

A. Non-follicular histological appearance.
B. Origin from parafollicular 'C' cells.
C. Secretion of calcitonin.
D. All of the above. (Correct Answer)

Explanation: **Explanation:** Medullary Thyroid Carcinoma (MTC) is a unique neuroendocrine tumor that accounts for approximately 5–10% of all thyroid malignancies. The correct answer is **D (All of the above)** because MTC differs fundamentally from other thyroid cancers (like papillary or follicular) in its embryology, histology, and secretory products. 1. **Origin from Parafollicular 'C' cells:** Unlike other thyroid cancers that arise from the follicular epithelium, MTC originates from the **parafollicular C-cells**, which are derived from the **ultimobranchial body** (neural crest cells). 2. **Non-follicular Histological Appearance:** Because it does not arise from follicular cells, it does not form follicles. Histologically, it is characterized by nests or sheets of polygonal cells separated by a fibrovascular stroma. A pathognomonic feature is the presence of **amyloid deposits** (derived from pro-calcitonin), which stain positive with **Congo Red** (showing apple-green birefringence). 3. **Secretion of Calcitonin:** C-cells normally produce calcitonin. Therefore, MTC cells secrete high levels of calcitonin, which serves as a highly specific **tumor marker** for diagnosis, screening, and monitoring recurrence. **High-Yield Clinical Pearls for NEET-PG:** * **Genetics:** Approximately 75% are sporadic, while 25% are familial (associated with **MEN 2A, MEN 2B**, and Familial MTC). All familial cases involve a mutation in the **RET proto-oncogene**. * **Tumor Markers:** Calcitonin (most specific) and **CEA** (useful for prognosis). * **Staining:** Positive for **Calcitonin, Chromogranin, and Synaptophysin**. * **Management:** MTC does **not** take up radioactive iodine (I-131). The primary treatment is Total Thyroidectomy with central compartment neck dissection.

Question 97: What is the standard surgical treatment for anaplastic carcinoma of the thyroid?

A. Hemithyroidectomy
B. Subtotal thyroidectomy
C. Near total thyroidectomy
D. Total thyroidectomy (Correct Answer)

Explanation: ### Explanation **Anaplastic Thyroid Carcinoma (ATC)** is one of the most aggressive solid tumors in humans, characterized by rapid growth and early local invasion. **Why Total Thyroidectomy is the Correct Answer:** The primary goal of surgery in ATC is **local disease control** and the prevention of airway obstruction (death by asphyxiation). If the tumor is resectable (confined to the thyroid or with minimal extrathyroidal extension), a **Total Thyroidectomy** is the standard surgical approach. It aims for an R0 or R1 resection to debulk the tumor, which improves the efficacy of adjuvant radiotherapy and chemotherapy. Even in advanced cases, surgery is often performed as a palliative measure to secure the airway. **Why Incorrect Options are Wrong:** * **A, B, & C (Hemithyroidectomy, Subtotal, and Near-total):** These procedures are oncologically inadequate for ATC. Leaving behind residual thyroid tissue increases the risk of rapid local recurrence and does not provide the necessary decompression of the trachea. In a malignancy this aggressive, anything less than a total thyroidectomy (when feasible) is considered incomplete treatment. **High-Yield Clinical Pearls for NEET-PG:** * **Presentation:** Typically presents in elderly patients (6th–7th decade) as a rapidly enlarging neck mass, often with hoarseness (RLN palsy) and dysphagia. * **Diagnosis:** Fine Needle Aspiration (FNA) may be suggestive, but **Core Needle Biopsy** or open biopsy is often required for definitive diagnosis (showing spindle, giant, or squamoid cells). * **Markers:** ATC is typically **negative for Thyroglobulin** and often loses expression of TTF-1. It may show positivity for PAX-8. * **Prognosis:** Extremely poor; the focus is often on palliative care, including tracheostomy if the tumor is unresectable. * **BRAF V600E Mutation:** Found in about 25% of cases; targeted therapy (Dabrafenib + Trametinib) is now a recognized treatment option.

Question 98: In papillary carcinoma of the thyroid, all of the following are true except?

A. It is the most common type of thyroid cancer.
B. Psammoma bodies are often seen.
C. It is not encapsulated.
D. Blood-borne metastasis is common. (Correct Answer)

Explanation: **Explanation:** The correct answer is **D (Blood-borne metastasis is common)** because Papillary Thyroid Carcinoma (PTC) primarily spreads via the **lymphatics** to regional cervical lymph nodes. Hematogenous (blood-borne) spread is rare in PTC (occurring in <5% of cases) and is much more characteristic of Follicular Thyroid Carcinoma (FTC). **Analysis of Options:** * **Option A:** PTC is indeed the **most common** thyroid malignancy, accounting for approximately 80–85% of all thyroid cancers. It has an excellent prognosis. * **Option B:** **Psammoma bodies** (laminated calcifications) are a classic histological hallmark found in about 50% of PTC cases. They represent infarcted tips of papillae. * **Option C:** Unlike follicular carcinoma, PTC is typically **not encapsulated**. It often presents as an infiltrative lesion, though a rare "encapsulated variant" does exist. **High-Yield NEET-PG Pearls:** * **Nuclear Features (Diagnostic):** Look for "Orphan Annie eye" nuclei (cleared-out chromatin), nuclear grooves, and pseudo-inclusions. * **Risk Factor:** Prior exposure to ionizing radiation is the most significant risk factor. * **Prognosis:** Excellent, with a 10-year survival rate >90%. * **Genetic Markers:** *BRAF* mutations (most common) and *RET/PTC* rearrangements. * **Treatment:** Total thyroidectomy or hemithyroidectomy (depending on size/risk) followed by Radioiodine (RAI) ablation if indicated.

Question 99: Which of the following is true about Papillary thyroid carcinoma?

A. More common in females
B. Lymph node metastasis is common
C. Can metastasize to lungs
D. All of the above (Correct Answer)

Explanation: **Explanation:** Papillary Thyroid Carcinoma (PTC) is the most common type of thyroid malignancy (approx. 80-85%). The correct answer is **"All of the above"** because PTC exhibits specific epidemiological and clinico-pathological characteristics: * **Option A (Gender Predilection):** Like most thyroid disorders, PTC is significantly more common in females, with a female-to-male ratio of approximately 3:1. * **Option B (Lymphatic Spread):** PTC is characteristically **lymphophilic**. Cervical lymph node metastasis is present in about 50-70% of cases at the time of diagnosis. Unlike Follicular carcinoma, which spreads hematogenously, PTC primarily spreads via the lymphatic system. * **Option C (Distant Metastasis):** While lymphatic spread is more common, PTC can spread hematogenously in advanced stages or aggressive variants. The **lungs** are the most common site for distant metastasis, followed by the bones. **High-Yield Clinical Pearls for NEET-PG:** 1. **Risk Factor:** History of exposure to ionizing radiation is the most significant risk factor. 2. **Microscopic Hallmarks:** * **Orphan Annie Eye nuclei:** Central clearing of the nucleus. * **Psammoma bodies:** Laminated calcifications (found in 50% of cases). * **Nuclear grooves** and **Pseudoinclusions**. 3. **Prognosis:** Generally excellent, especially in younger patients. The **AMES** or **MACIS** scoring systems are used for prognosis. 4. **Investigation of Choice:** FNAC is the gold standard for diagnosis (Note: FNAC cannot distinguish between Follicular Adenoma and Carcinoma, but it *can* diagnose Papillary Carcinoma).

Question 100: Which of the following is the first vein ligated during thyroidectomy?

A. Superior thyroid vein
B. Middle thyroid vein (Correct Answer)
C. Inferior thyroid vein
D. Thyroid ima vein

Explanation: In thyroid surgery, the sequence of vessel ligation is critical for both exposure and safety. ### Why the Middle Thyroid Vein is Ligated First The **middle thyroid vein** is the first vessel to be ligated during a thyroidectomy. Unlike the superior and inferior veins, the middle thyroid vein is short, wide, and runs directly lateral from the thyroid gland to the internal jugular vein (IJV). * **Surgical Rationale:** Ligating this vein early allows the surgeon to "mobilize" the thyroid gland. Once divided, the gland can be rotated medially, providing the necessary exposure to safely identify and ligate the superior and inferior poles and visualize the recurrent laryngeal nerve (RLN). ### Explanation of Incorrect Options * **A. Superior Thyroid Vein:** This is ligated as part of the superior pole dissection. It is usually addressed after mobilization has begun. * **C. Inferior Thyroid Vein:** These veins form a plexus (plexus thyroideus impar) at the lower pole. They are typically ligated later in the procedure during the dissection of the inferior pole. * **D. Thyroid Ima Vein:** This is an inconsistent anatomical variant (present in ~3–10% of people) arising from the brachiocephalic trunk or arch of aorta. While it must be ligated if present, it is not the standard first step. ### High-Yield Clinical Pearls for NEET-PG * **The "Danger" Zone:** When ligating the **superior thyroid artery**, stay **close to the gland** to avoid injuring the **external branch of the superior laryngeal nerve**. * **The "Safe" Zone:** When ligating the **inferior thyroid artery**, ligate it **away from the gland** (trunk ligation) to avoid injuring the **recurrent laryngeal nerve**. * **Kocher’s Incision:** The standard transverse collar incision used for thyroidectomy, placed two fingerbreadths above the suprasternal notch.

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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