Endocrine Surgery — MCQs

Endocrine Surgery Indian Medical PG Practice Questions and MCQs

Question 181: Which of the following is NOT a feature of medullary carcinoma of the thyroid?

A. Arises from parafollicular cells
B. Amyloid infiltrate is present on histology
C. 10-25% of cases are familial
D. Constipation occurs (Correct Answer)

Explanation: **Explanation:** Medullary Carcinoma of Thyroid (MCT) is a neuroendocrine tumor derived from the **parafollicular C-cells** of the thyroid. These cells are responsible for the secretion of **Calcitonin**. **Why Option D is the correct answer:** MCT is associated with **diarrhea**, not constipation. The tumor secretes high levels of Calcitonin, prostaglandins, and serotonin, which increase intestinal motility and lead to secretory diarrhea. This is a classic paraneoplastic feature of the disease. **Analysis of other options:** * **Option A:** MCT originates from the **ultimobranchial body** (parafollicular C-cells), which are neural crest in origin. This distinguishes it from papillary and follicular cancers, which arise from follicular cells. * **Option B:** A hallmark histological feature of MCT is the presence of **amyloid stroma**. This amyloid is formed by the deposition of pro-calcitonin molecules and stains positive with **Congo Red** (showing apple-green birefringence). * **Option C:** Approximately **20-25%** of MCT cases are familial, occurring as part of **MEN 2A, MEN 2B**, or Familial MCT (FMCT). These are associated with the **RET proto-oncogene** mutation. **High-Yield Clinical Pearls for NEET-PG:** * **Tumor Marker:** Calcitonin (used for diagnosis and monitoring recurrence) and CEA. * **Genetics:** All patients with MCT must be screened for **RET mutations** and **Pheochromocytoma** (before thyroid surgery). * **Staining:** Positive for Calcitonin, Chromogranin, and Synaptophysin. * **Spread:** MCT spreads via both lymphatic and hematogenous routes. * **Treatment:** Total thyroidectomy with central compartment neck dissection is the standard of care. It is **not** sensitive to Radioiodine (I-131) therapy.

Question 182: A patient with multinodular goiter developed pain and difficulty in breathing. Which of the following types of thyroid carcinoma is most likely to cause this complication?

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

Explanation: **Explanation:** The clinical presentation of a long-standing multinodular goiter (MNG) suddenly developing **pain, rapid enlargement, and obstructive symptoms** (dyspnea, dysphagia, or hoarseness) is a classic hallmark of **Anaplastic Thyroid Carcinoma (ATC)**. **1. Why Anaplastic Carcinoma is correct:** ATC is one of the most aggressive solid tumors in humans. It often arises from a pre-existing differentiated thyroid cancer or a long-standing MNG in elderly patients. Its hallmark is **rapid local invasion** into surrounding structures like the trachea (causing breathing difficulty), esophagus (dysphagia), and recurrent laryngeal nerve (hoarseness). The rapid growth stretches the thyroid capsule, leading to significant pain. **2. Why the other options are incorrect:** * **Papillary Carcinoma (B):** The most common thyroid cancer; it is typically slow-growing, painless, and spreads via lymphatics. It rarely causes acute respiratory distress unless in very advanced, neglected stages. * **Follicular Carcinoma (C):** Usually presents as a solitary "cold" nodule. It spreads hematogenously (to bones and lungs) and rarely causes acute local pressure symptoms or pain. * **Medullary Carcinoma (A):** Arises from parafollicular C-cells. While it can be aggressive, it does not typically show the explosive growth or acute painful presentation characteristic of ATC. **Clinical Pearls for NEET-PG:** * **Age Group:** ATC typically affects the elderly (6th–7th decade). * **Diagnosis:** Often requires **Core Needle Biopsy** or Incisional Biopsy because FNAC may only show necrosis or be inconclusive. * **Histology:** Shows spindle cells, giant cells, and pleomorphic cells. * **Prognosis:** Extremely poor; treatment is often palliative (tracheostomy for airway) as most cases are unresectable at presentation.

Question 183: What is the approximate amount of thyroid tissue typically left on each side after a subtotal thyroidectomy?

A. 4 grams on one side
B. 4 grams on each side (Correct Answer)
C. 6 grams on one side
D. 6 grams on each side

Explanation: **Explanation:** **Subtotal thyroidectomy** is a surgical procedure traditionally performed for multinodular goiter or Graves' disease. The primary objective is to render the patient euthyroid while preserving enough tissue to avoid permanent hypothyroidism and protecting the parathyroid glands and recurrent laryngeal nerves. 1. **Why Option B is correct:** In a standard subtotal thyroidectomy (specifically the Hartley-Dunhill procedure or bilateral subtotal resection), the surgeon leaves approximately **4 grams of thyroid tissue on each side** (totaling 8 grams). This amount is considered sufficient to maintain normal thyroid function, as a healthy adult thyroid gland typically weighs between 15 and 25 grams. 2. **Why other options are incorrect:** * **Options A & C:** Leaving tissue on only "one side" describes a **Hartley-Dunhill procedure** (where a total lobectomy is done on one side and a subtotal on the other). However, the standard definition of a bilateral subtotal thyroidectomy implies leaving tissue on both sides. * **Option D:** Leaving 6 grams on each side (12 grams total) increases the risk of recurrence, especially in toxic goiters, without providing significant additional benefit for hormone production. **NEET-PG High-Yield Pearls:** * **Hartley-Dunhill Procedure:** Total lobectomy on one side + Subtotal lobectomy (leaving 4g) on the other side. * **Near-total Thyroidectomy:** Leaving <1 gram of tissue (usually near the Berry’s ligament) to protect the recurrent laryngeal nerve. * **Current Trend:** In modern practice, total thyroidectomy is often preferred over subtotal thyroidectomy for both malignancy and multinodular goiter to eliminate the risk of recurrence and the difficulty of "re-do" surgery. * **Complication Check:** The most common cause of hoarseness post-surgery is unilateral recurrent laryngeal nerve injury; the most common cause of post-op tetany is transient hypocalcemia due to parathyroid stunning.

Question 184: What is the stage of an adrenocortical carcinoma measuring 6cm without invasion of surrounding structures?

A. Stage I Adrenocortical carcinoma
B. Stage II Adrenocortical carcinoma (Correct Answer)
C. Stage III Adrenocortical carcinoma
D. Stage IV Adrenocortical carcinoma

Explanation: The staging of Adrenocortical Carcinoma (ACC) primarily follows the **ENSAT (European Network for the Study of Adrenal Tumors)** classification, which is the gold standard for NEET-PG. ### **Explanation of the Correct Answer** **Stage II** is defined as a tumor measuring **>5 cm** in its greatest dimension, which is confined to the adrenal gland (no invasion of surrounding fat or organs) and has no lymph node or distant metastasis (T2 N0 M0). Since the question specifies a **6 cm** tumor without invasion, it fits the criteria for Stage II. ### **Analysis of Incorrect Options** * **Stage I:** This stage is reserved for tumors measuring **≤5 cm** that are confined to the adrenal gland (T1 N0 M0). * **Stage III:** This stage involves local invasion into surrounding adipose tissue, adjacent organs (like the kidney or liver), or the presence of positive regional lymph nodes (T3/T4 or N1). * **Stage IV:** This stage is characterized by the presence of distant metastasis (M1), regardless of the tumor size or local invasion. ### **High-Yield Clinical Pearls for NEET-PG** * **ENSAT vs. AJCC:** ENSAT is preferred over AJCC because it better correlates with prognosis, particularly in distinguishing Stage III and IV. * **Imaging:** CT scan showing high unenhanced attenuation (>10 HU) and slow contrast washout is suspicious for ACC. * **Biopsy Contraindication:** Never perform a fine-needle aspiration (FNA) if ACC is suspected, as it carries a high risk of **capsular track seeding**. * **Treatment:** Radical surgical resection (R0) is the only curative treatment. **Mitotane** is the standard adjuvant therapy for high-risk patients.

Question 185: Which of the following statements about a solitary thyroid nodule are TRUE?

A. 1, 2, and 3 are true, while 4 and 5 are false.
B. 1, 3, and 5 are true, while 2 and 4 are false.
C. 1, 2, and 3 are false, while 4 and 5 are true. (Correct Answer)
D. None of the statements are true.

Explanation: To master the management of a **Solitary Thyroid Nodule (STN)**, one must differentiate between clinical myths and evidence-based surgical principles. ### **Analysis of Statements** 1. **Statement 1 (False):** "Most solitary nodules are malignant." In reality, only **5–15%** of STNs are malignant; the vast majority are benign (e.g., colloid nodules or adenomas). 2. **Statement 2 (False):** "Hot nodules on scintigraphy are likely to be malignant." **Hot (functioning) nodules** are almost always benign (<1% risk). It is the **"Cold" nodules** that carry a higher risk of malignancy (approx. 15–20%). 3. **Statement 3 (False):** "FNAC can reliably distinguish between follicular adenoma and carcinoma." This is a classic NEET-PG trap. FNAC assesses cytology, not architecture. Since the diagnosis of follicular carcinoma requires evidence of **capsular or vascular invasion**, FNAC cannot differentiate the two; histopathology (post-thyroidectomy) is required. 4. **Statement 4 (True):** "Ultrasound is the most sensitive tool for detecting nodules." USG can detect nodules as small as 2mm and identify suspicious features (microcalcifications, irregular margins, taller-than-wide shape). 5. **Statement 5 (True):** "The first step in evaluation is TSH levels." If TSH is suppressed, the next step is a Radionuclide scan (to look for a "hot" nodule). If TSH is normal or high, the next step is USG and FNAC. ### **Why Option C is Correct** Statements 1, 2, and 3 are factually incorrect based on surgical pathology and diagnostic protocols, while 4 and 5 represent the standard of care in the initial workup. ### **High-Yield Clinical Pearls** * **Gold Standard Investigation:** FNAC is the most cost-effective and accurate tool for initial diagnosis (except for follicular lesions). * **Risk Factors for Malignancy:** History of neck radiation, male gender, extremes of age (<20 or >70 years), and hard/fixed consistency. * **TIRADS:** A standardized USG reporting system used to stratify the risk of malignancy and determine the need for FNAC.

Question 186: In which of the following is medullary thyroid cancer considered the most aggressive form?

A. Multiple endocrine neoplasia type I (MEN I)
B. Multiple endocrine neoplasia type IIa (MEN IIa)
C. Multiple endocrine neoplasia type IIb (MEN IIb) (Correct Answer)
D. Sporadic cases

Explanation: **Explanation:** Medullary Thyroid Cancer (MTC) arises from the parafollicular C-cells and is a hallmark of Multiple Endocrine Neoplasia (MEN) type 2 syndromes. The aggressiveness of MTC is directly linked to the specific germline mutation of the **RET proto-oncogene**. **Why MEN IIb is the correct answer:** MEN IIb is characterized by the **M918T mutation** in exon 16 of the RET gene. This specific mutation leads to the most aggressive biological behavior of MTC. In MEN IIb, MTC presents at a very young age (often in infancy), has a 100% penetrance, and metastasizes much earlier than in other forms. Due to this extreme virulence, prophylactic thyroidectomy is recommended within the **first year of life**. **Analysis of Incorrect Options:** * **MEN I (Wermer Syndrome):** This syndrome involves the "3 Ps" (Pituitary, Parathyroid, and Pancreas). It is **not** associated with Medullary Thyroid Cancer. * **MEN IIa (Sipple Syndrome):** While MTC is the most common feature of MEN IIa, it typically presents in the 2nd or 3rd decade of life and is less aggressive than the IIb variant. Prophylactic thyroidectomy is usually recommended by age 5. * **Sporadic Cases:** About 75% of MTC cases are sporadic. These generally present later in life (4th–6th decade) and are typically less aggressive than the syndromic MEN IIb variety. **High-Yield Clinical Pearls for NEET-PG:** * **Tumor Marker:** Serum **Calcitonin** is used for diagnosis and monitoring recurrence; **CEA** is a secondary marker. * **MEN IIb Phenotype:** Look for "Marfanoid habitus," mucosal neuromas (tongue/lips), and ganglioneuromatosis of the GI tract. * **Rule of Priority:** In any MEN 2 case, always exclude or treat **Pheochromocytoma** before performing thyroid surgery to prevent a hypertensive crisis. * **Staining:** MTC shows **Apple-green birefringence** under polarized light with Congo red stain due to amyloid deposition.

Question 187: A 50-year-old male presents with severe dyspnea following thyroid surgery. What is the treatment of choice?

A. Tracheostomy
B. Open the operative site (Correct Answer)
C. Wait and watch
D. Cricothyroidotomy

Explanation: **Explanation:** The most common cause of acute respiratory distress immediately following thyroid surgery is a **tension hematoma** (post-operative hemorrhage). This occurs due to arterial bleeding (often from the superior thyroid artery) deep to the strap muscles. The accumulation of blood creates pressure that causes venous and lymphatic obstruction, leading to laryngeal edema and compression of the trachea. **Why "Open the operative site" is correct:** This is a surgical emergency. The immediate priority is to **decompress the neck** by opening the surgical incision and the underlying strap muscles at the bedside. This relieves the pressure on the airway, restores venous drainage, and allows the patient to breathe while being prepared for a formal re-exploration in the operating room to achieve definitive hemostasis. **Why other options are incorrect:** * **Tracheostomy:** This is a time-consuming procedure and technically difficult in a neck distorted by a large hematoma. It is not the first-line treatment for acute post-thyroidectomy airway obstruction. * **Cricothyroidotomy:** While an emergency airway procedure, it does not address the underlying cause (compression). Decompressing the hematoma is faster and more effective in this specific scenario. * **Wait and watch:** This is contraindicated as the condition can rapidly progress to total airway occlusion and cardiac arrest. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of post-op dyspnea (0-2 hours):** Tension hematoma. * **Most common cause of post-op dyspnea (after 24 hours):** Hypocalcemia (causing laryngospasm) or bilateral Recurrent Laryngeal Nerve (RLN) injury. * **Management Priority:** Always **Decompress first, Intubate second.** Do not wait for an anesthesiologist or transfer to the OR to open the wound if the patient is in distress.

Question 188: Which is the least common type of thyroid malignancy?

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

Explanation: **Explanation:** The frequency of thyroid malignancies follows a specific hierarchy based on their cellular origin and differentiation. **Anaplastic thyroid carcinoma (ATC)** is the correct answer as it is the rarest form, accounting for only **1–2%** of all thyroid cancers. It is an undifferentiated tumor, typically presenting in elderly patients as a rapidly enlarging neck mass with early local invasion and a very poor prognosis. **Analysis of Options:** * **A. Papillary (80–85%):** This is the **most common** type of thyroid malignancy. It is associated with radiation exposure and has the best prognosis. Characteristic features include Psammoma bodies and Orphan Annie eye nuclei. * **B. Follicular (10–15%):** The second most common type. It is characterized by hematogenous spread (unlike papillary, which spreads via lymphatics) and requires histological evidence of capsular or vascular invasion for diagnosis. * **C. Medullary (5%):** Arises from the parafollicular C-cells and secretes Calcitonin. It can be sporadic or associated with MEN 2A/2B syndromes. While less common than Papillary or Follicular, it is still more frequent than Anaplastic. **High-Yield Clinical Pearls for NEET-PG:** * **Most Common overall:** Papillary Carcinoma. * **Least Common / Worst Prognosis:** Anaplastic Carcinoma. * **Most Common in Iodine-Deficient areas:** Follicular Carcinoma. * **Tumor Marker for Medullary:** Calcitonin (used for diagnosis and follow-up). * **Diagnosis:** FNAC can diagnose Papillary, Medullary, and Anaplastic, but **cannot** distinguish between Follicular Adenoma and Carcinoma (requires biopsy).

Question 189: Which of the following treatment modalities for papillary carcinoma is obsolete nowadays?

A. Near total thyroidectomy
B. Modified radical neck dissection
C. Suppressive lifelong dose of L-thyroxine
D. Berry picking of involved lymph nodes (Correct Answer)

Explanation: **Explanation:** **Berry picking** refers to the selective removal of only the clinically enlarged or palpable lymph nodes in the neck, rather than a systematic compartmental dissection. This modality is now considered **obsolete** because Papillary Thyroid Carcinoma (PTC) has a high propensity for lymphatic spread, often involving "skip metastases" and microscopic disease in non-palpable nodes. Berry picking is associated with a high rate of local recurrence and the need for difficult re-operations in a scarred field. Modern surgical standards mandate a formal **Central Neck Dissection (Level VI)** or **Modified Radical Neck Dissection (MRND)** if nodes are involved. **Analysis of Incorrect Options:** * **Near Total Thyroidectomy:** This remains a valid surgical option for PTC (leaving <1 gram of tissue near the recurrent laryngeal nerve) to reduce the risk of hypoparathyroidism while still allowing for adjuvant Radioiodine (RAI) therapy. * **Modified Radical Neck Dissection (MRND):** This is the **standard of care** for clinically positive lateral neck nodes (Levels II-V). It removes the lymphatic tissue while preserving non-lymphatic structures (Internal Jugular Vein, Sternocleidomastoid muscle, and Spinal Accessory nerve). * **Suppressive lifelong dose of L-thyroxine:** PTC cells express TSH receptors. Giving supraphysiological doses of Thyroxine suppresses TSH levels, thereby reducing the stimulus for the growth of any residual microscopic tumor cells. This remains a cornerstone of post-operative management. **Clinical Pearls for NEET-PG:** * **Most common** site of metastasis in PTC: Central compartment lymph nodes (Level VI). * **Standard Surgery:** Total Thyroidectomy is preferred if the tumor is >4 cm, has extrathyroidal extension, or positive nodes. * **Prognostic Scoring:** AMES, MACIS, and TNM are used to predict outcomes in PTC. * **Psammoma bodies:** Characteristic histological finding in Papillary Carcinoma (calcified laminated structures).

Question 190: A young girl presented with swelling in the neck which moves on deglutition. She complains of dyspnea and venous engorgement in the face. The clinician performed a test, and the name of this sign is:

A. Pemberton sign (Correct Answer)
B. Lahey test
C. Crile test
D. Gifford test

Explanation: ### Explanation **1. Why Pemberton Sign is Correct:** The clinical presentation describes a **Retrosternal Goiter**. When a large goiter extends into the superior mediastinum, it can cause a "thoracic inlet syndrome." The **Pemberton sign** is elicited by asking the patient to raise both arms above the head until they touch the sides of the face for 30–60 seconds. * **Mechanism:** This maneuver further narrows the thoracic inlet, causing the goiter to compress the internal jugular and subclavian veins against the clavicles/ribs. * **Clinical Findings:** Facial congestion, cyanosis, respiratory distress (stridor), and prominent neck veins. This confirms the presence of obstructive retrosternal extension. **2. Why the Other Options are Incorrect:** * **Lahey Test:** This is a physical examination technique used to palpate the thyroid gland. The clinician pushes the trachea to one side to make the contralateral lobe more prominent and easier to palpate. * **Crile Test:** Similar to the Lahey test, this involves palpating the thyroid gland by placing the thumb over the thyroid cartilage and asking the patient to swallow to feel for nodules or enlargement. * **Gifford Test:** This is an ocular sign seen in **Graves' ophthalmopathy**, characterized by difficulty in everting the upper eyelid. **3. High-Yield Clinical Pearls for NEET-PG:** * **Retrosternal Goiter Definition:** A goiter where >50% of the mass is below the thoracic inlet. * **Most Common Symptom:** Dyspnea (due to tracheal compression). * **Imaging of Choice:** CT scan (without contrast is preferred if radioactive iodine therapy is planned) to assess the extent of mediastinal involvement. * **Treatment:** Most retrosternal goiters can be removed via a standard cervical incision; a sternotomy is required in less than 5% of cases.

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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