Endocrine Surgery — MCQs

Endocrine Surgery Indian Medical PG Practice Questions and MCQs

Question 121: Papillary carcinoma of the thyroid usually presents as:

A. Diffuse nodular swelling
B. Only lymphadenopathy
C. Hormonal disturbance
D. Single nodule with local lymph node involvement (Correct Answer)

Explanation: **Explanation:** **Papillary Thyroid Carcinoma (PTC)** is the most common malignancy of the thyroid gland (approx. 80%). Its hallmark clinical presentation is a **slow-growing, painless solitary thyroid nodule**. Unlike other thyroid cancers, PTC is highly **lymphophilic**. It spreads primarily via the lymphatic system to the central (Level VI) and lateral neck nodes. Consequently, at the time of diagnosis, approximately 30–50% of adults (and up to 80% of children) already have clinically palpable or ultrasound-detectable **cervical lymphadenopathy**. **Analysis of Options:** * **Option D (Correct):** Accurately reflects the classic presentation of a dominant single nodule associated with regional lymph node involvement. * **Option A:** Diffuse nodular swelling is more characteristic of Multinodular Goiter (MNG) or Hashimoto’s thyroiditis, though PTC can occasionally arise within an MNG. * **Option B:** While "lateral aberrant thyroid" (lymph node metastasis) can be the first sign, it is rarely the *only* finding; a primary thyroid nodule is almost always present upon careful imaging. * **Option C:** PTC is a non-functional tumor. Patients are typically **euthyroid**. Hormonal disturbances (hyperthyroidism) are more suggestive of toxic nodules or Graves' disease. **High-Yield Clinical Pearls for NEET-PG:** * **Microscopic Hallmark:** Psammoma bodies (calcified laminated bodies) and "Orphan Annie eye" nuclei (empty-appearing nuclei). * **Risk Factor:** Prior exposure to ionizing radiation. * **Prognosis:** Excellent, with a 10-year survival rate >90%. * **Diagnosis:** Fine Needle Aspiration Cytology (FNAC) is the investigation of choice (Note: FNAC cannot distinguish Follicular Adenoma from Carcinoma, but it is definitive for Papillary).

Question 122: A 26-year-old woman presents with a palpable thyroid nodule. Needle biopsy demonstrates amyloid in the stroma of the lesion. A cervical lymph node is palpable on the same side as the lesion. What is the preferred treatment?

A. Removal of the involved node, the isthmus, and the enlarged lymph node.
B. Removal of the involved lobe, the isthmus, a portion of the opposite lobe, and the enlarged lymph node.
C. Total thyroidectomy and modified neck dissection on the side of the enlarged lymph node. (Correct Answer)
D. Total thyroidectomy and irradiation of the cervical lymph nodes.

Explanation: ### Explanation **1. Understanding the Diagnosis** The presence of **amyloid in the stroma** on needle biopsy is pathognomonic for **Medullary Thyroid Carcinoma (MTC)**. MTC arises from the parafollicular C-cells, which secrete calcitonin; this calcitonin undergoes misfolding to form the characteristic amyloid deposits. **2. Why Option C is Correct** * **Total Thyroidectomy:** MTC is frequently multicentric (especially in familial cases) and does not respond to TSH suppression or radioactive iodine. Therefore, complete removal of the gland is mandatory. * **Modified Radical Neck Dissection (MRND):** MTC has a high propensity for early lymphatic spread. The presence of a palpable cervical lymph node indicates metastatic involvement, necessitating a therapeutic neck dissection on the involved side to achieve locoregional control. **3. Why Other Options are Incorrect** * **Options A & B:** These represent subtotal or hemithyroidectomies. These are inadequate for MTC because they leave behind thyroid tissue that may harbor multicentric disease and increase the risk of recurrence. * **Option D:** MTC is **radioresistant**. External beam radiation is not a primary treatment for nodal disease and cannot replace surgical clearance. **4. NEET-PG High-Yield Pearls** * **Tumor Marker:** Serum **Calcitonin** (for diagnosis/follow-up) and **CEA** (for prognosis). * **Genetic Association:** 25% of cases are part of **MEN 2A or 2B** (RET proto-oncogene mutation). Always screen for **Pheochromocytoma** before thyroid surgery to prevent intraoperative hypertensive crisis. * **Prophylactic Surgery:** In RET mutation carriers, prophylactic total thyroidectomy is recommended (timing depends on the specific codon mutation). * **Staining:** Amyloid shows **apple-green birefringence** under polarized light with Congo Red stain.

Question 123: All of the following are complications of total thyroidectomy, EXCEPT:

A. Hemorrhage
B. Hoarseness
C. Hypercalcemia (Correct Answer)
D. Airway obstruction

Explanation: ### Explanation The correct answer is **C. Hypercalcemia**. **1. Why Hypercalcemia is the correct answer:** Total thyroidectomy involves the removal of the entire thyroid gland. The parathyroid glands, which regulate calcium levels, are located on the posterior surface of the thyroid. During surgery, these glands may be accidentally removed, devascularized, or suffer from temporary ischemia. This leads to **Hypocalcemia** (low calcium), not hypercalcemia. Post-operative hypocalcemia is, in fact, the most common metabolic complication following total thyroidectomy. **2. Why the other options are incorrect:** * **Hemorrhage (A):** Thyroid surgery is highly vascular. A "tension hematoma" can develop post-operatively, which is a surgical emergency. * **Hoarseness (B):** This occurs due to injury to the **Recurrent Laryngeal Nerve (RLN)**. Unilateral injury causes hoarseness, while bilateral injury can cause life-threatening airway obstruction. * **Airway Obstruction (D):** This can be caused by several factors: a compressive hematoma, bilateral RLN palsy, or **Tracheomalacia** (softening of tracheal rings due to long-standing large goiters). **3. Clinical Pearls for NEET-PG:** * **Most common complication overall:** Hypocalcemia (transient in 20%, permanent in <2%). * **Most common cause of immediate post-op respiratory distress:** Tension hematoma (Treatment: Immediate bedside stitch removal/evacuation). * **Nerve injury:** Injury to the **External Branch of the Superior Laryngeal Nerve** leads to loss of high-pitched voice (inability to hit high notes) due to cricothyroid muscle paralysis. * **Chvostek’s and Trousseau’s signs:** Clinical markers for latent hypocalcemia post-thyroidectomy.

Question 124: A 40-year-old female presents with neck swelling. Examination reveals a 2x2 cm nodule on the right lobe of the thyroid with no palpable cervical nodes. FNAC shows features of papillary carcinoma. What is the treatment of choice?

A. Total thyroidectomy (Correct Answer)
B. Right hemithyroidectomy
C. Hartley-Dunhill operation
D. Subtotal thyroidectomy

Explanation: **Explanation:** The management of Papillary Thyroid Carcinoma (PTC) is a high-yield topic for NEET-PG. According to the current American Thyroid Association (ATA) and British Thyroid Association (BTA) guidelines, the surgical approach is determined by the size of the nodule and risk factors. **1. Why Total Thyroidectomy is correct:** For a 2 cm (2x2 cm) papillary carcinoma, **Total Thyroidectomy** is the treatment of choice. While some guidelines allow for lobectomy in low-risk tumors between 1–4 cm, in the context of Indian competitive exams (NEET-PG/INI-CET), any PTC **>1 cm**, or those with bilateral disease, extrathyroidal extension, or metastases, warrants a Total Thyroidectomy. This procedure facilitates the use of Radioiodine (RAI) ablation post-operatively and allows for the use of Serum Thyroglobulin as a highly sensitive tumor marker for follow-up. **2. Why other options are incorrect:** * **Right Hemithyroidectomy:** This is generally reserved for "Microcarcinomas" (PTC <1 cm) confined to one lobe without high-risk features. For a 2 cm lesion, it increases the risk of recurrence and complicates follow-up. * **Hartley-Dunhill Operation:** This involves a total lobectomy on one side and a subtotal lobectomy on the other. It is an obsolete procedure for malignancy as it leaves behind significant thyroid tissue, making RAI therapy ineffective. * **Subtotal Thyroidectomy:** This leaves 4–6 grams of tissue on both sides. It is contraindicated in thyroid malignancy due to high recurrence rates and the inability to monitor recurrence via Thyroglobulin. **Clinical Pearls for NEET-PG:** * **Most common thyroid cancer:** Papillary Carcinoma (80-85%). * **Characteristic FNAC findings:** Orphan Annie eye nuclei, Psammoma bodies, and Nuclear grooves. * **Lymphatic spread:** PTC primarily spreads via lymphatics (Level VI nodes first). * **Prognosis:** Excellent; the 10-year survival rate is >90%.

Question 125: Thyroxine can be given in which thyroid carcinoma?

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

Explanation: **Explanation:** The correct answer is **Papillary Thyroid Carcinoma (PTC)**. **1. Why Papillary is Correct:** Papillary and Follicular carcinomas are "Differentiated Thyroid Cancers" (DTCs). These tumor cells originate from **follicular cells** and often retain the physiological characteristics of normal thyroid tissue, including **TSH receptors**. TSH (Thyroid Stimulating Hormone) acts as a growth factor for these malignant cells. By administering exogenous **Thyroxine (L-Thyroxine)**, we achieve "TSH Suppression" via the negative feedback loop. Lowering TSH levels reduces the stimulus for tumor growth and recurrence, making it a cornerstone of post-operative management in DTCs. **2. Why Other Options are Incorrect:** * **Medullary Carcinoma:** This tumor arises from **Parafollicular C-cells** (which produce Calcitonin), not follicular cells. C-cells do not have TSH receptors; therefore, TSH suppression with Thyroxine has no therapeutic effect on the tumor itself. * **Anaplastic / Undifferentiated Carcinoma:** These are highly aggressive tumors that have lost all features of thyroid differentiation. They do not express TSH receptors and are unresponsive to hormonal manipulation. **Clinical Pearls for NEET-PG:** * **Target TSH Levels:** In high-risk PTC patients, the goal is often TSH <0.1 mU/L. In low-risk patients, it is usually 0.1–0.5 mU/L. * **Radioiodine (I-131) Therapy:** Only Papillary and Follicular cancers (DTCs) take up iodine. Medullary and Anaplastic do not. * **Marker of Recurrence:** Thyroglobulin is the follow-up marker for PTC/Follicular; Calcitonin is the marker for Medullary. * **Psammoma Bodies:** These are a classic histological finding in Papillary Thyroid Carcinoma.

Question 126: A 2 cm nodule in the left thyroid is diagnosed as papillary carcinoma. What is the treatment of choice?

A. Hemithyroidectomy
B. Total thyroidectomy (Correct Answer)
C. Thyroidectomy with radical neck dissection
D. Radiotherapy

Explanation: **Explanation:** The management of Papillary Thyroid Carcinoma (PTC) is primarily surgical. According to standard guidelines (ATA/NCCN), the size of the nodule is a critical determinant for the extent of surgery. **Why Total Thyroidectomy is correct:** For a differentiated thyroid carcinoma (like PTC) that is **>1 cm and up to 4 cm**, **Total Thyroidectomy** is the preferred treatment of choice in the context of competitive exams like NEET-PG. It allows for the use of Radioiodine (RAI) ablation post-operatively to destroy residual microscopic disease and enables the use of Serum Thyroglobulin as a highly sensitive tumor marker for follow-up. **Why other options are incorrect:** * **Hemithyroidectomy:** While current ATA guidelines suggest lobectomy may be sufficient for low-risk tumors between 1-4 cm, in the Indian context and for exam purposes, any lesion **>1 cm** generally warrants a total thyroidectomy to facilitate monitoring and prevent recurrence in the contralateral lobe (which occurs in up to 30-40% of cases due to multicentricity). * **Radical Neck Dissection:** This is an aggressive procedure involving the removal of the SCM, internal jugular vein, and spinal accessory nerve. It is not indicated for PTC unless there is extensive, fixed nodal involvement. Functional or Modified Radical Neck Dissection is preferred if nodes are involved. * **Radiotherapy:** PTC is a radioresistant tumor. External beam radiation is only used as a palliative measure for unresectable or recurrent disease. **High-Yield Clinical Pearls for NEET-PG:** * **Size Criteria:** <1 cm (Microcarcinoma) → Hemithyroidectomy; >1 cm to 4 cm → Total Thyroidectomy (standard exam answer); >4 cm or extrathyroidal extension → Total Thyroidectomy. * **Multicentricity:** PTC is frequently multicentric (bilateral), which is a strong argument for total thyroidectomy. * **Psammoma Bodies:** A classic histological finding in PTC (calcified laminated bodies). * **Orphan Annie Eye Nuclei:** Characteristic nuclear clearing seen on histopathology.

Question 127: What is the best treatment for a 2 cm thyroid nodule in a 50-year-old man, where Fine Needle Aspiration Cytology (FNAC) reveals papillary carcinoma?

A. Hemithyroidectomy
B. Subtotal thyroidectomy with modified neck dissection
C. Near total thyroidectomy with central neck dissection (Correct Answer)
D. Hemithyroidectomy with modified neck dissection

Explanation: ### Explanation The management of Papillary Thyroid Carcinoma (PTC) is guided by risk stratification based on age, tumor size, and nodal involvement. **1. Why Option C is Correct:** In a 50-year-old male with a 2 cm nodule, the patient falls into a higher risk category (Age >45-55 years and tumor size >1 cm). According to standard surgical guidelines (ATA/British Thyroid Association), **Total or Near-total Thyroidectomy** is the treatment of choice for tumors >1 cm in patients over 45. Furthermore, PTC is highly lymphophilic, frequently spreading to the **Level VI (central compartment)** lymph nodes. Prophylactic or therapeutic central neck dissection is often performed alongside total thyroidectomy to reduce recurrence and facilitate post-operative monitoring with Serum Thyroglobulin and Radioiodine (RAI) ablation. **2. Why Other Options are Incorrect:** * **Option A (Hemithyroidectomy):** This is generally reserved for low-risk "microcarcinomas" (<1 cm), unifocal tumors in young patients (<45 years), or low-risk follicular lesions. It is insufficient for a 2 cm tumor in a 50-year-old. * **Option B & D (Modified Radical Neck Dissection - MRND):** MRND (addressing levels II-V) is only indicated if there is **clinically or radiologically proven lateral cervical lymphadenopathy**. It is not performed routinely for a 2 cm nodule without evidence of lateral spread. * **Subtotal Thyroidectomy:** This procedure is largely obsolete in modern oncological surgery as it leaves behind significant thyroid tissue, making RAI ablation ineffective and increasing the risk of recurrence. **Clinical Pearls for NEET-PG:** * **Most common thyroid cancer:** Papillary Carcinoma (80-85%). * **Characteristic Histology:** Orphan Annie eye nuclei, Psammoma bodies, and nuclear grooves. * **Prognostic Scoring:** AMES (Age, Metastasis, Extent, Size) and MACIS are used to predict outcomes. * **Follow-up:** Serum Thyroglobulin acts as a tumor marker post-total thyroidectomy.

Question 128: What is the treatment for medullary carcinoma of the thyroid?

A. Total Thyroidectomy (Correct Answer)
B. Subtotal Thyroidectomy
C. Near total Thyroidectomy
D. Lobectomy

Explanation: **Explanation:** Medullary Thyroid Carcinoma (MTC) arises from the **parafollicular C-cells** (derived from the neural crest), which secrete calcitonin. Unlike differentiated thyroid cancers (Papillary or Follicular), MTC does not concentrate iodine and is often multicentric, especially in familial cases (MEN 2A/2B). **Why Total Thyroidectomy is the Correct Choice:** The standard of care for MTC is **Total Thyroidectomy** because the disease is frequently bilateral and multicentric. Since C-cells are distributed throughout both lobes, any remaining thyroid tissue poses a high risk of recurrence. Furthermore, because MTC cells do not take up radioactive iodine (RAI), surgery is the only definitive curative modality; residual disease cannot be "cleaned up" with RAI ablation post-operatively. **Analysis of Incorrect Options:** * **Subtotal/Near-total Thyroidectomy:** These procedures leave behind thyroid tissue. In MTC, this is oncologically inadequate due to the high risk of multicentricity and the inability to use adjuvant RAI. * **Lobectomy:** This is insufficient because MTC is often bilateral (up to 90% in familial cases and 20% in sporadic cases). It is only considered in very rare, incidental micro-medullary cancers, but for exam purposes, Total Thyroidectomy remains the gold standard. **High-Yield Clinical Pearls for NEET-PG:** * **Lymph Node Dissection:** Total thyroidectomy should be accompanied by a **Central Compartment Neck Dissection (Level VI)** because MTC has a high rate of early lymphatic spread. * **Screening:** Always rule out **Pheochromocytoma** (via urinary/plasma metanephrines) before surgery in MTC patients to prevent a hypertensive crisis during anesthesia. * **Tumor Markers:** **Calcitonin** is used for diagnosis and monitoring recurrence; **CEA** is a useful secondary marker for prognosis. * **Genetic Testing:** All patients with MTC should be screened for **RET proto-oncogene** mutations.

Question 129: Complete resection of the thyroid gland on one side, while leaving less than 1 gram of tissue adjacent to the ligament of berry on the opposite side, is termed?

A. Thyroid lobectomy
B. Subtotal thyroidectomy
C. Near-total thyroidectomy (Correct Answer)
D. Bilateral lobectomy

Explanation: ### Explanation The correct answer is **Near-total thyroidectomy**. **1. Understanding the Correct Answer** A **Near-total thyroidectomy** involves the total removal of one thyroid lobe (lobectomy) along with the isthmus, and the removal of almost all of the contralateral lobe. A small amount of thyroid tissue (**less than 1 gram or <1 cm**) is intentionally left behind, typically near the **Ligament of Berry** or the superior pole. This is done to protect vital structures, specifically the **Recurrent Laryngeal Nerve (RLN)** and the **parathyroid glands**, while still achieving a near-complete resection of the disease. **2. Analysis of Incorrect Options** * **A. Thyroid lobectomy:** This involves the removal of only one lobe of the thyroid gland, usually along with the isthmus (Hemithyroidectomy). The contralateral lobe remains untouched. * **B. Subtotal thyroidectomy:** In this procedure, a significant portion of thyroid tissue (**4–5 grams**) is left on **both sides** to maintain euthyroid status post-operatively. It is less extensive than a near-total thyroidectomy. * **D. Bilateral lobectomy:** This is a synonymous term for **Total Thyroidectomy**, where both lobes and the isthmus are completely removed, leaving no macroscopic thyroid tissue behind. **3. NEET-PG High-Yield Pearls** * **Total Thyroidectomy** is the treatment of choice for most thyroid malignancies (Papillary/Follicular >1cm) and Medullary Thyroid Carcinoma. * **Hartley-Dunhill Procedure:** This is a specific type of near-total thyroidectomy where a total lobectomy is performed on one side and a subtotal resection on the other. * **Ligament of Berry:** The most common site for RLN injury during thyroid surgery because the nerve often passes through or deep to this ligament. * **Post-op Complication:** The most common cause of hypocalcemia post-thyroidectomy is temporary ischemia to the parathyroid glands.

Question 130: Which of the following statements is false regarding medullary carcinoma?

A. Calcitonin serves as a tumor marker.
B. It arises from the neural crest.
C. It is associated with MEN 1 syndrome. (Correct Answer)
D. Diarrhea is a predominant symptom.

Explanation: **Explanation:** Medullary Thyroid Carcinoma (MTC) is a unique thyroid malignancy that arises from the **parafollicular C-cells**. These cells are embryologically derived from the **neural crest** (making Option B true) and are responsible for secreting **Calcitonin**. **Why Option C is the correct (false) statement:** MTC is strongly associated with **MEN 2A and MEN 2B** syndromes, but **not MEN 1**. MEN 1 (Wermer’s Syndrome) typically involves the "3 Ps": Pituitary, Parathyroid, and Pancreatic tumors. In contrast, MEN 2 is characterized by the presence of MTC, Pheochromocytoma, and either Hyperparathyroidism (2A) or Mucosal neuromas/Marfanoid habitus (2B). **Analysis of other options:** * **Option A:** Calcitonin is the primary hormone produced by C-cells. It serves as a highly sensitive **tumor marker** for diagnosis, screening, and monitoring recurrence. * **Option D:** In advanced or metastatic MTC, high levels of circulating calcitonin and other peptides (like prostaglandins or VIP) alter intestinal water and electrolyte transport, leading to **secretory diarrhea**. **High-Yield Clinical Pearls for NEET-PG:** * **Genetics:** Most cases are sporadic, but 20-25% are familial, associated with the **RET proto-oncogene** mutation. * **Pathology:** Characterized by **amyloid stroma** (stained with Congo Red showing apple-green birefringence). * **Spread:** It spreads via both lymphatic and hematogenous routes. * **Surgery:** The treatment of choice is **Total Thyroidectomy** with central compartment neck dissection. It does *not* respond to Radioiodine (I-131) therapy because C-cells do not concentrate iodine.

Practice by Chapter

Thyroid Nodules

Practice Questions

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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