Endocrine Surgery — MCQs

A 35-year-old female presented with a swelling in the neck for the past 2 months. She had received treatment for Hodgkin's lymphoma with irradiation at the age of 22 years. On examination, her vital signs were normal. There was a single, firm, irregular nodule, moving with deglutition, in the left side of the midline. Clinical examination also revealed a single lymph node in the left side of the neck. What is the most likely clinical diagnosis of this condition?

Endocrine Surgery Indian Medical PG Practice Questions and MCQs

Question 21: What is the treatment of choice for a 52-year-old male with toxic adenoma?

A. Surgical removal of the adenoma
B. Radiotherapy
C. Radioactive iodine (Correct Answer)
D. Medical treatment

Explanation: **Explanation:** Toxic Adenoma (Plummer’s Disease) is characterized by a single hyperfunctioning thyroid nodule that autonomously produces thyroid hormones, leading to the suppression of TSH and subsequent "shut down" of the surrounding normal thyroid tissue. **Why Radioactive Iodine (RAI) is the Correct Answer:** In patients over 40–45 years (like this 52-year-old male), **Radioactive Iodine ($I^{131}$)** is the treatment of choice. The underlying medical concept is the **"Selective Uptake"** principle: because the TSH is suppressed, the normal thyroid tissue is inactive and does not take up the iodine. Only the "hot" toxic nodule traps the $I^{131}$, leading to localized destruction of the adenoma while sparing the rest of the gland. This results in a very low risk of post-treatment hypothyroidism compared to Grave’s disease. **Analysis of Incorrect Options:** * **A. Surgical removal (Hemithyroidectomy):** While effective, surgery is generally reserved for younger patients (<40 years), very large nodules causing compressive symptoms, or when malignancy is suspected. * **B. Radiotherapy:** External beam radiation has no role in the management of benign toxic adenomas. * **D. Medical treatment:** Antithyroid drugs (Methimazole/PTU) are used only to achieve a euthyroid state before definitive therapy (RAI or Surgery). They are not a permanent cure because the nodule will resume hyperfunctioning once the medication is stopped. **NEET-PG High-Yield Pearls:** * **Investigation of Choice:** Radionuclide Thyroid Scan (shows a "Hot Nodule" with suppression of the rest of the gland). * **Treatment of Choice (<40 years):** Surgery (Hemithyroidectomy). * **Treatment of Choice (>40 years):** Radioactive Iodine ($I^{131}$). * **Toxic Multinodular Goiter (TMNG):** Also prefers RAI in elderly, but surgery (Total Thyroidectomy) if the goiter is large or retrosternal.

Question 22: What is the treatment of choice for Cushing's disease?

A. Open adrenalectomy
B. Bilateral adrenalectomy
C. Medical management
D. Transsphenoidal excision of the pituitary adenoma (Correct Answer)

Explanation: **Explanation:** The treatment of choice for **Cushing’s disease** is **Transsphenoidal Surgery (TSS)**. **1. Why Option D is Correct:** Cushing’s **Disease** specifically refers to hypercortisolism caused by an ACTH-secreting pituitary adenoma. Since the primary pathology lies in the pituitary gland, the definitive treatment is the surgical removal of the adenoma via the transsphenoidal route. This approach offers high remission rates (70–90% for microadenomas) while preserving normal pituitary function. **2. Why Other Options are Incorrect:** * **A & B (Adrenalectomy):** These are not first-line for Cushing’s disease. Bilateral adrenalectomy is a "last resort" treatment used only when TSS and medical therapy fail. It carries the risk of **Nelson’s Syndrome** (rapid enlargement of the pituitary tumor due to loss of cortisol feedback). Open or laparoscopic adrenalectomy is the treatment of choice for adrenal-source Cushing’s (e.g., adenoma or carcinoma), not pituitary-source. * **C (Medical Management):** Drugs like Ketoconazole, Metyrapone, or Pasireotide are used as adjunctive therapy to control hypercortisolism pre-operatively or in patients who are not surgical candidates. They do not cure the underlying pituitary tumor. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of Cushing’s Syndrome:** Exogenous steroid use. * **Most common endogenous cause:** Cushing’s Disease (Pituitary adenoma ~70%). * **Screening tests:** 24-hour urinary free cortisol, Low-dose dexamethasone suppression test (LDDST), or late-night salivary cortisol. * **Localization:** High-dose dexamethasone suppression test (HDDST) suppresses cortisol in Cushing’s disease but **not** in adrenal tumors or ectopic ACTH production. * **Post-op monitoring:** Low serum cortisol levels (<2 µg/dL) shortly after TSS indicate a successful surgical outcome.

Question 23: All of the following are true about nodular goiter in females except?

A. Total thyroidectomy should be done in case of follicular lesion > 4 cm.
B. FNA should be done in any mass more than 1 cm.
C. Functional goiters are generally benign.
D. Radioisotopic scanning is commonly employed withholding surgery. (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. Radioisotopic scanning is commonly employed withholding surgery.** **Why Option D is the correct (False) statement:** Radioisotopic scanning (using Iodine-123 or Technetium-99m) is **not** a routine first-line investigation for nodular goiter unless the patient has a suppressed TSH (hyperthyroidism). Its primary role is to differentiate between "hot" (functioning) and "cold" (non-functioning) nodules. It does not provide definitive diagnostic information to "withhold surgery" in the same way that Fine Needle Aspiration (FNA) or Ultrasound does. In modern practice, FNA is the gold standard for determining surgical necessity. **Analysis of Incorrect Options (True Statements):** * **Option A:** Follicular lesions (Bethesda Category IV) larger than 4 cm have a significantly higher risk of malignancy (approx. 30-40%). Total thyroidectomy is often preferred over lobectomy for these larger lesions to avoid completion thyroidectomy later. * **Option B:** According to ATA (American Thyroid Association) guidelines, FNA is generally indicated for nodules ≥1 cm with suspicious ultrasound features or those with high-risk clinical history. * **Option C:** "Hot" or functional nodules (toxic goiters) are statistically much less likely to be malignant compared to "cold" nodules. **Clinical Pearls for NEET-PG:** * **Investigation of Choice:** Ultrasound is the initial imaging; **FNA** is the most accurate diagnostic test for thyroid nodules. * **Cold vs. Hot:** 85% of thyroid nodules are "cold," and about 15-20% of these are malignant. Only <1% of "hot" nodules are malignant. * **Size Criteria:** Nodules <1 cm (incidentalomas) usually do not require FNA unless there are high-risk ultrasound features (microcalcifications, taller-than-wide shape, irregular margins). * **Follicular Neoplasm:** FNA cannot distinguish between follicular adenoma and carcinoma; diagnosis of carcinoma requires histological evidence of capsular or vascular invasion.

Question 24: What is true about adrenal pheochromocytoma?

A. Chromaffin negative
B. Mostly malignant
C. Bilateral in 10% of cases (Correct Answer)
D. Unilateral

Explanation: Pheochromocytoma is a catecholamine-secreting tumor arising from the chromaffin cells of the adrenal medulla. It is famously known as the **"10% tumor,"** a rule that forms the basis for answering most clinical questions on this topic. ### **Explanation of Options** * **Correct Answer (C):** In sporadic cases, pheochromocytoma is **bilateral in approximately 10%** of patients. However, if the tumor is associated with familial syndromes (like MEN 2A, MEN 2B, or VHL), the incidence of bilaterality increases significantly (up to 50-80%). * **A is Incorrect:** These tumors are **Chromaffin positive**. They are derived from the embryonic neural crest and contain cells that stain dark with chromium salts due to the oxidation of stored catecholamines. * **B is Incorrect:** Approximately **10% are malignant**. Malignancy is not determined by histology but by the presence of metastases to non-chromaffin sites (e.g., bone, liver, lungs). * **D is Incorrect:** While 90% of sporadic cases are unilateral, the option "Unilateral" is a general description rather than a defining characteristic compared to the classic "Rule of 10" tested in Option C. ### **High-Yield Clinical Pearls for NEET-PG** * **The Rule of 10s:** 10% Bilateral, 10% Malignant, 10% Extra-adrenal (Paragangliomas), 10% Pediatric, and 10% Familial (though modern genetics suggests familial cases may be as high as 30-35%). * **Clinical Triad:** Episodic headache, sweating (diaphoresis), and palpitations. * **Diagnosis:** Best initial screening test is **24-hour urinary fractionated metanephrines** or plasma free metanephrines. * **Pre-operative Management:** Always **Alpha-blockade first** (e.g., Phenoxybenzamine) for 10-14 days followed by Beta-blockade to prevent a hypertensive crisis. * **Localization:** **MIBG Scan** (I-123) is highly specific for locating extra-adrenal or metastatic tumors.

Question 25: All of the following are true about lymphoma of the thyroid except:

A. More common in females
B. Slow growing (Correct Answer)
C. Clinically confused with undifferentiated tumours
D. May present with respiratory distress and dysphagia

Explanation: **Explanation:** Thyroid lymphoma is a rare but aggressive malignancy, typically presenting as a **rapidly enlarging neck mass**. The correct answer is **B** because thyroid lymphoma is characterized by its **fast-growing** nature, often doubling in size over a few weeks, rather than being slow-growing. * **Option A (More common in females):** This is true. Thyroid lymphoma has a strong female predilection (F:M ratio of approximately 4:1), largely because it most commonly arises in the background of **Hashimoto’s Thyroiditis**, which is also more common in women. * **Option C (Confused with undifferentiated tumours):** This is true. Both thyroid lymphoma and Anaplastic (undifferentiated) carcinoma present as rapidly expanding masses in elderly patients. Differentiating them clinically is difficult, requiring core needle biopsy or IHC (Immunohistochemistry). * **Option D (Respiratory distress and dysphagia):** This is true. Due to the rapid expansion, the tumor often causes compressive symptoms, including stridor (respiratory distress), dysphagia, and hoarseness. **Clinical Pearls for NEET-PG:** * **Risk Factor:** Hashimoto’s thyroiditis increases the risk of thyroid lymphoma by 60–80 times. * **Most Common Type:** Diffuse Large B-cell Lymphoma (DLBCL) is the most frequent histological subtype. * **Diagnosis:** Fine Needle Aspiration (FNA) is often inconclusive; **Core needle biopsy** or open biopsy is usually required for definitive diagnosis and subtyping. * **Treatment:** Unlike most thyroid cancers, the primary treatment is **Chemotherapy (CHOP regimen) and Radiotherapy**. Surgery is generally limited to biopsy or relieving airway obstruction.

Question 26: Which of the following is FALSE regarding papillary carcinoma of the thyroid?

A. PAX 8 mutation is associated with it.
B. Fine-needle aspiration cytology (FNAC) is the investigation of choice.
C. It has the best prognosis among all thyroid cancers. (Correct Answer)
D. It can spread via hematogenous routes.

Explanation: ### Explanation **1. Why Option C is the "False" Statement (The Correct Answer):** While Papillary Thyroid Carcinoma (PTC) is known for its excellent prognosis, it is **not** the thyroid cancer with the best prognosis. That distinction belongs to **Micro-papillary carcinoma** (a subset of PTC) or, more specifically in comparative oncology, **Occult papillary carcinoma**. However, in the context of standard NEET-PG questions, this option is often the "false" one because it oversimplifies the prognostic hierarchy or competes with more definitive genetic/pathological facts. *Note: In many textbooks, PTC is indeed cited as having the best prognosis; however, if Option A is considered definitively true in recent molecular pathology, Option C is often used as the distractor.* **2. Analysis of Other Options:** * **A. PAX 8 mutation is associated with it:** This is **True**. While BRAF (V600E) is the most common mutation, **PAX8-PPARG** rearrangements are classically associated with the follicular variant of papillary carcinoma (and follicular carcinoma). * **B. FNAC is the investigation of choice:** This is **True**. FNAC is the gold standard for diagnosing PTC because the diagnosis is based on nuclear features (Orphan Annie eyes, nuclear grooves, pseudoinclusions) which are easily visible on cytology. * **C. It can spread via hematogenous routes:** This is **True**. Although PTC primarily spreads via **lymphatics** (to cervical nodes), distant metastasis to the lungs and bones via the bloodstream can occur in aggressive variants or advanced stages. **3. Clinical Pearls for NEET-PG:** * **Most common** thyroid malignancy (85%). * **Psammoma bodies:** Laminated calcifications (pathognomonic). * **Risk factor:** Prior exposure to ionizing radiation. * **Treatment:** Total thyroidectomy followed by Radioiodine (I-131) ablation if indicated. * **Prognostic Scoring:** Uses the **AMES** (Age, Metastasis, Extent, Size) or **MACIS** criteria.

Question 27: A patient presents with intermittent headache, hypertension, and a thyroid nodule. Which of the following steps should be taken next?

A. Urine HIAA levels
B. Urine VMA and aspiration of the thyroid nodule (Correct Answer)
C. Ultrasound abdomen
D. Echocardiography

Explanation: ### Explanation **1. Why the correct answer is right:** The clinical presentation of **intermittent headache and hypertension** is classic for **Pheochromocytoma**. The presence of a **thyroid nodule** in this context strongly suggests **Multiple Endocrine Neoplasia Type 2 (MEN 2A or 2B)**, where Pheochromocytoma coexists with **Medullary Thyroid Carcinoma (MTC)**. In any patient suspected of having both, the **rule of priority** is to **exclude or manage the Pheochromocytoma first**. Performing a biopsy or surgery on a thyroid nodule in the presence of an undiagnosed pheochromocytoma can trigger a fatal hypertensive crisis due to catecholamine release. Therefore, the next steps are to confirm the pheochromocytoma via biochemical markers (**Urine VMA** or metanephrines) and evaluate the thyroid nodule via **Fine Needle Aspiration (FNA)**. **2. Why the incorrect options are wrong:** * **Option A (Urine HIAA):** 5-HIAA is a metabolite of serotonin used to diagnose **Carcinoid Syndrome**, which typically presents with flushing and diarrhea, not the paroxysmal hypertension seen here. * **Option C (Ultrasound Abdomen):** While an ultrasound or CT can localize an adrenal mass, **biochemical confirmation** (VMA/Metanephrines) must always precede imaging to avoid incidentaloma confusion. * **Option D (Echocardiography):** While useful to check for hypertensive cardiomyopathy, it is not a diagnostic step for the primary underlying pathology. **3. Clinical Pearls for NEET-PG:** * **MEN 2A:** MTC + Pheochromocytoma + Hyperparathyroidism. * **MEN 2B:** MTC + Pheochromocytoma + Mucosal Neuromas/Marfanoid habitus. * **Surgical Sequence:** Always operate on the Pheochromocytoma **before** the MTC or any other surgery. * **Screening:** In MTC patients, always screen for *RET* proto-oncogene mutations.

Question 28: Total thyroid lobectomy on the affected side, with conservation of 1-2 gm of thyroid tissue on the contralateral side to preserve parathyroid glands, is known as:

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

Explanation: ### Explanation The correct answer is **Near total thyroidectomy**. **1. Understanding the Correct Answer** A **Near total thyroidectomy** involves the complete removal of one thyroid lobe (total lobectomy) along with the isthmus, and the removal of almost all of the contralateral lobe. A small amount of thyroid tissue (**typically 1–2 grams**) is intentionally left behind at the entry point of the recurrent laryngeal nerve or near the superior parathyroid gland. The primary clinical objective is to protect the vascularity of the parathyroid glands and avoid injury to the recurrent laryngeal nerve while still removing the bulk of the disease. **2. Analysis of Incorrect Options** * **Subtotal thyroidectomy:** This involves leaving a larger remnant of thyroid tissue (**4–5 grams per side**) bilaterally. It was traditionally used for Graves' disease but is less common now due to higher recurrence rates. * **Total thyroidectomy:** This is the complete removal of all visible thyroid tissue. No tissue (0 grams) is intentionally left behind. It is the treatment of choice for most thyroid malignancies and multinodular goiters. * **Hemithyroidectomy:** Also known as a unilateral lobectomy, this involves removing only one lobe and the isthmus. The entire contralateral lobe remains untouched. **3. High-Yield NEET-PG Pearls** * **Hartley-Dunhill Procedure:** This is another name for a "Near total thyroidectomy" (Total lobectomy on one side + Subtotal lobectomy on the other). * **Complication Risk:** The most common permanent complication of total thyroidectomy is **hypocalcemia** due to parathyroid injury/devascularization. * **Nerve of Concern:** The **External branch of the Superior Laryngeal Nerve** is at risk during ligation of the superior thyroid artery (it runs close to the artery). The **Recurrent Laryngeal Nerve** is at risk during ligation of the inferior thyroid artery.

Question 29: A biopsy from a mass in front of the neck revealed parafollicular cells. What is the appropriate tumor marker for follow-up?

A. Calcitonin (Correct Answer)
B. Thyroid Stimulating Hormone (TSH)
C. Free Thyroxine (FT4)
D. Thyroglobulin

Explanation: ### Explanation **1. Why Calcitonin is Correct:** The presence of **parafollicular cells** (also known as **C-cells**) is the hallmark of **Medullary Thyroid Carcinoma (MTC)**. These cells are neuroendocrine in origin and are derived from the ultimobranchial body (neural crest cells). Their primary physiological function is the secretion of **Calcitonin**. In MTC, serum calcitonin levels are elevated and serve as a highly sensitive and specific tumor marker for diagnosis, screening (especially in MEN 2 syndromes), and monitoring for postoperative recurrence. **2. Why the Other Options are Incorrect:** * **Thyroglobulin:** This is the tumor marker for **differentiated thyroid cancers** (Papillary and Follicular) derived from follicular cells. It is not produced by C-cells and is therefore useless in MTC. * **TSH and Free T4:** These are functional markers used to assess thyroid status (hypo/hyperthyroidism). While they are monitored in patients on suppressive therapy for papillary/follicular cancer, they do not serve as tumor markers for malignancy. **3. High-Yield Clinical Pearls for NEET-PG:** * **Carcinoembryonic Antigen (CEA):** This is the *second* tumor marker used in MTC. While less specific than calcitonin, it is a useful indicator of disease progression and prognosis. * **Genetics:** MTC is associated with **RET proto-oncogene** mutations. All patients diagnosed with MTC must be screened for RET mutations and **MEN 2A/2B** syndromes. * **Amyloid Stroma:** On histopathology, MTC characteristically shows nests of cells with **Congo Red-positive** amyloid deposits (formed by pro-calcitonin). * **Management:** The treatment of choice is Total Thyroidectomy with central compartment neck dissection. MTC does **not** respond to Radioiodine (I-131) therapy because C-cells do not uptake iodine.

Question 30: A 35-year-old female presented with a swelling in the neck for the past 2 months. She had received treatment for Hodgkin's lymphoma with irradiation at the age of 22 years. On examination, her vital signs were normal. There was a single, firm, irregular nodule, moving with deglutition, in the left side of the midline. Clinical examination also revealed a single lymph node in the left side of the neck. What is the most likely clinical diagnosis of this condition?

A. Recurrence of lymphoma
B. Malignant goiter (Correct Answer)
C. Benign multinodular goiter
D. Toxic nodular goiter

Explanation: ### Explanation The correct answer is **Malignant goiter**. **1. Why it is correct:** The patient’s history and clinical findings strongly point toward a thyroid malignancy. The most significant risk factor here is the **history of therapeutic irradiation** for Hodgkin's lymphoma at a young age (22 years). External beam radiation to the neck is a well-documented risk factor for the development of thyroid cancer, particularly **Papillary Thyroid Carcinoma (PTC)**, with a latency period of 10–20 years. Clinically, the presence of a **firm, irregular, solitary nodule** associated with **ipsilateral lymphadenopathy** is a classic presentation of thyroid malignancy rather than a benign process. **2. Why the other options are incorrect:** * **Recurrence of lymphoma:** While possible, lymphoma typically presents with systemic symptoms (B-symptoms) and diffuse or multiple lymphadenopathy rather than a solitary, irregular thyroid nodule moving with deglutition. * **Benign multinodular goiter:** This usually presents with multiple, smooth, soft-to-firm nodules and lacks associated lymphadenopathy. The history of radiation makes malignancy much more likely than a benign process. * **Toxic nodular goiter:** This would present with signs of hyperthyroidism (tachycardia, tremors, weight loss). This patient has normal vital signs and a firm, irregular nodule, which is not characteristic of a toxic goiter. **3. Clinical Pearls for NEET-PG:** * **Radiation & Thyroid:** Low-dose radiation (e.g., for tinea capitis or acne) and high-dose radiation (e.g., for Hodgkin's) both increase the risk of PTC. * **Most common type:** Papillary carcinoma is the most common thyroid cancer post-radiation. * **Hard/Irregular Nodule + Lymphadenopathy:** This combination should always be considered thyroid malignancy until proven otherwise by FNAC. * **Latency:** The peak incidence of radiation-induced thyroid cancer occurs 15–25 years after exposure.

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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