Endocrine Surgery Practice Questions

Q: 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:

Near total thyroidectomy.. ### 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.

Q: 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?

Malignant goiter. ### 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.

Q: A 40-year-old woman is found to have a 15-mm nontender thyroid nodule on the right lobe during routine evaluation. She has no prior history of thyroid disease, feels well, and has normal thyroid function tests. There is no associated lymphadenopathy. What is the most appropriate next step in management?

Fine needle aspiration (FNA) biopsy. ### Explanation The management of a thyroid nodule is a high-yield topic for NEET-PG, focusing on the systematic exclusion of malignancy. **Why Option B is Correct:** The initial step in evaluating a thyroid nodule is checking the **Serum TSH** [1]. In this patient, thyroid function tests are normal (euthyroid). According to the American Thyroid Association (ATA) guidelines, any solid thyroid nodule **>1 cm (10 mm)** with normal TSH should undergo **Fine Needle Aspiration (FNA) biopsy** to rule out malignancy. FNA is the gold standard and the most cost-effective diagnostic tool for differentiating benign from malignant lesions. **Why Other Options are Incorrect:** * **Option A (Thyroid Scan):** Radionuclide scanning is only indicated if the TSH is **low (suppressed)** to identify a "hot" (functioning) nodule, which is rarely malignant [1]. It has no role in a euthyroid patient. In such cases, scintigraphy is not routinely used when TSH is normal [1]. * **Option C (Repeat assessment):** Observation is only appropriate for nodules <1 cm that do not have high-risk ultrasound features. A 15-mm nodule requires immediate pathological evaluation. * **Option D (Partial thyroidectomy):** Surgery is a definitive treatment, not a diagnostic step. It is only considered after FNA results suggest malignancy (Bethesda Category V or VI) or follicular neoplasm. **Clinical Pearls for NEET-PG:** * **Size Cut-off:** Generally, FNA is indicated for nodules ≥1 cm if solid/hypoechoic, or ≥1.5 cm if iso/hyperechoic. * **TSH First:** Always check TSH first [1]. If TSH is low $\rightarrow$ Scan; if TSH is normal/high $\rightarrow$ FNA. * **Bethesda System:** FNA results are reported via the Bethesda Classification (I-VI). * **Risk Factors:** History of childhood neck irradiation or a family history of Medullary Thyroid Carcinoma increases the suspicion of malignancy regardless of size.

Q: Which is the best treatment for the management of malignant pheochromocytoma?

I131-MIBG. **Explanation:** The management of **malignant pheochromocytoma** is challenging because malignancy is defined only by the presence of metastases in non-chromaffin tissues (e.g., bone, liver, lungs), not by histology. **Why I131-MIBG is the best treatment:** Metaiodobenzoguanidine (MIBG) is a compound structurally similar to norepinephrine, which is actively taken up by chromaffin cells via the norepinephrine transporter. When tagged with **Iodine-131**, it delivers targeted radiotherapy directly to metastatic sites. It is considered the most effective systemic therapy for symptomatic, unresectable, or widespread malignant disease, offering both symptomatic relief and tumor stabilization. **Analysis of Incorrect Options:** * **Alpha blockers (A):** These are essential for **pre-operative preparation** and symptom control (managing hypertension) but do not treat the underlying malignancy or reduce tumor burden. * **Chemotherapy (B):** The CVD regimen (Cyclophosphamide, Vincristine, and Dacarbazine) is used for rapidly progressing tumors, but response rates are generally lower and more toxic compared to MIBG therapy. * **Bulk reducing surgery (C):** While cytoreductive surgery (debulking) can help reduce catecholamine excess, it is palliative and rarely curative in a malignant setting. It is not the "best" primary treatment for systemic spread. **High-Yield Clinical Pearls for NEET-PG:** * **Rule of 10s:** Pheochromocytoma is 10% bilateral, 10% extra-adrenal, and **10% malignant**. * **Genetic Association:** Malignancy is more common in patients with **SDHB mutations**. * **Diagnosis:** The most sensitive screening test is **Plasma free metanephrines**; the most specific is **24-hour urinary metanephrines**. * **Pre-op Prep:** Always start **Alpha-blockers first** (e.g., Phenoxybenzamine) before Beta-blockers to avoid a hypertensive crisis (unopposed alpha stimulation).

Q: A 30-year-old male has papillary thyroid carcinoma with a nodule less than 3 cm confined to the neck, along with 2 palpable lymph nodes in the neck and micro-metastasis in the lungs. According to the AJCC 8th edition, how would you stage this patient?

Stage II. ### Explanation The staging of Papillary Thyroid Carcinoma (PTC) underwent a significant paradigm shift in the **AJCC 8th Edition**, primarily centered on the age of the patient. **1. Why Stage II is Correct:** In the AJCC 8th edition, the age cutoff for staging was increased from 45 to **55 years**. For patients **younger than 55 years**, there are only two possible stages: * **Stage I:** Any T, Any N, **M0** (No distant metastasis). * **Stage II:** Any T, Any N, **M1** (Distant metastasis present). Since this patient is 30 years old (under 55) and has **micro-metastasis in the lungs (M1)**, he is automatically classified as **Stage II**, regardless of the tumor size (T) or lymph node involvement (N). **2. Why Other Options are Incorrect:** * **Stage I:** This would be correct if the patient had no distant metastasis (M0). Even with positive lymph nodes, a patient <55 years remains Stage I if there is no M1. * **Stage III & IV:** These stages **do not exist** for patients under the age of 55 in the AJCC 8th edition. These categories are reserved exclusively for patients aged 55 and older. **3. NEET-PG High-Yield Pearls:** * **Age Cutoff:** Remember **55 years** is the magic number for thyroid cancer staging. * **Younger (<55):** Only Stage I (M0) or Stage II (M1). Death is rare in this group. * **Older (≥55):** Staging follows the traditional I-IV system based on T, N, and M. * **Nodal Status:** In patients <55, N1 (lymph node metastasis) does **not** change the stage from I to II; only M1 does. * **Prognosis:** PTC has an excellent prognosis; the change in age cutoff reflects the low mortality in younger patients even with nodal spread.

Q: Which of the following is NOT a characteristic of medullary carcinoma of the thyroid?

TSH dependent. ### Explanation **1. Why "TSH dependent" is the correct (False) statement:** Medullary Thyroid Carcinoma (MTC) originates from the **parafollicular C-cells** (neuroendocrine cells) of the thyroid, which are derived from the **ultimobranchial body** (neural crest cells). Unlike papillary and follicular carcinomas, which arise from follicular cells and have TSH receptors, C-cells do not possess TSH receptors. Therefore, MTC is **not TSH-dependent**, and TSH suppression therapy has no role in its management. **2. Analysis of incorrect options:** * **Contains amyloid:** A hallmark histological feature of MTC is the presence of extracellular **amyloid deposits**, which represent pro-calcitonin fibrils. These stain positive with **Congo Red** and show apple-green birefringence under polarized light. * **Secretes calcitonin:** Calcitonin is the primary biomarker for MTC. It is used for diagnosis, monitoring treatment response, and detecting recurrence. Some tumors also secrete CEA (Carcinoembryonic Antigen). * **RET point mutation (Chromosome 10):** Approximately 25% of MTC cases are familial (MEN 2A, 2B, or Familial MTC). These are associated with germline mutations in the **RET proto-oncogene** located on chromosome 10. All patients diagnosed with MTC must be screened for this mutation to guide family screening and prophylactic thyroidectomy. **Clinical Pearls for NEET-PG:** * **Most common site:** Junction of the upper 1/3rd and lower 2/3rds of the thyroid lobe (highest concentration of C-cells). * **Spread:** Early lymphatic spread to central and lateral neck nodes is common. * **MEN 2A:** MTC + Pheochromocytoma + Hyperparathyroidism. * **MEN 2B:** MTC + Pheochromocytoma + Mucosal neuromas + Marfanoid habitus. * **Surgery:** Total thyroidectomy with central compartment neck dissection is the treatment of choice.

Q: What is the most common life-threatening complication of thyroidectomy?

Haemorrhage. **Explanation:** The most common life-threatening complication following thyroidectomy is **post-operative haemorrhage** (specifically, a tension haematoma). 1. **Why Haemorrhage is Correct:** While rare (occurring in ~1-2% of cases), a bleed into the tight subplatysmal space leads to a rapid buildup of pressure. This does not cause death by simple blood loss, but by **mechanical compression of the airway** and venous congestion leading to laryngeal edema. It is a surgical emergency requiring immediate bedside decompression (opening the sutures) to restore the airway. 2. **Why Other Options are Incorrect:** * **Tracheal Collapse (Tracheomalacia):** This occurs due to long-standing pressure from a large goiter softening the tracheal rings. While life-threatening, it is significantly less common than post-operative bleeding in modern surgical practice. * **Laryngeal Edema:** This is often a *secondary* result of venous obstruction caused by a haematoma or trauma from intubation, rather than the primary life-threatening event itself. * **Bilateral Vocal Cord Palsy:** Caused by bilateral Recurrent Laryngeal Nerve (RLN) injury. While it causes acute airway obstruction (stridor) requiring tracheostomy, its incidence is much lower than haemorrhage due to improved nerve monitoring and surgical techniques. **Clinical Pearls for NEET-PG:** * **Most common complication overall:** Hypocalcaemia (transient). * **Most common nerve injured:** External branch of the Superior Laryngeal Nerve (leads to loss of high-pitched voice). * **Timing:** Post-thyroidectomy haemorrhage typically occurs within the first **6 to 24 hours**. * **Management:** The immediate step for a post-op patient with respiratory distress and neck swelling is **opening the wound at the bedside**, not waiting for an OR or intubation.

Q: Which of the following statements about hyperparathyroidism is FALSE?

It commonly occurs after thyroidectomy.. **Explanation:** **1. Why Option A is the Correct (False) Statement:** Hyperparathyroidism refers to the **overactivity** of the parathyroid glands. Thyroidectomy is a common cause of **hypoparathyroidism**, not hyperparathyroidism. During thyroid surgery, the parathyroid glands may be inadvertently removed, devascularized, or traumatized, leading to a deficiency in Parathyroid Hormone (PTH) and subsequent hypocalcemia. Therefore, stating that hyperparathyroidism commonly occurs after thyroidectomy is medically incorrect. **2. Analysis of Incorrect Options:** * **Option B (It may cause hypercalcemia):** This is a **true** statement. PTH increases bone resorption, renal calcium reabsorption, and intestinal calcium absorption (via Vitamin D). Excess PTH directly leads to elevated serum calcium levels. * **Option C (Solitary adenoma is the most common cause):** This is a **true** statement. Approximately 80–85% of primary hyperparathyroidism cases are caused by a single benign adenoma. Other causes include gland hyperplasia (15%) and rare parathyroid carcinoma (<1%). **3. High-Yield Clinical Pearls for NEET-PG:** * **Classic Presentation:** Often described by the mnemonic "Bones, Stones, Abdominal Groans, and Psychic Moans" (osteitis fibrosa cystica, nephrolithiasis, peptic ulcers/pancreatitis, and depression/confusion). * **Biochemical Hallmark:** Elevated Serum Calcium + Elevated/Inappropriately Normal PTH + Low Serum Phosphate. * **Localization:** Sestamibi scan (Technetium-99m) is the gold standard for preoperative localization of an adenoma. * **Hungry Bone Syndrome:** A common postoperative complication after parathyroidectomy where rapid bone remineralization leads to severe hypocalcemia.

Q: Which type of thyroid cancer is considered the least malignant?

Papillary carcinoma. **Explanation:** Thyroid carcinomas exhibit a wide spectrum of biological behavior, ranging from indolent to highly aggressive. **Papillary Thyroid Carcinoma (PTC)** is the most common thyroid malignancy (80-85%) and is considered the **least malignant** because it is slow-growing, well-differentiated, and has an excellent 10-year survival rate (often >95%). While it frequently spreads via lymphatics to cervical nodes, this does not significantly worsen the overall prognosis in younger patients. **Analysis of Options:** * **A. Papillary Carcinoma (Correct):** It has the best prognosis. Key features include Orphan Annie eye nuclei, Psammoma bodies, and a strong association with ionizing radiation. * **B. Follicular Carcinoma:** More aggressive than PTC. It spreads hematogenously (to bone and lungs) rather than lymphatically. It is associated with iodine deficiency. * **C. Medullary Carcinoma:** Arises from parafollicular C-cells (secretes Calcitonin). It is more aggressive than well-differentiated cancers and can be part of MEN 2A/2B syndromes. * **D. Anaplastic Carcinoma:** The most aggressive/malignant form. It is undifferentiated, grows rapidly, causes early local invasion (airway obstruction), and is almost always fatal within months. **High-Yield Clinical Pearls for NEET-PG:** * **Prognosis Order (Best to Worst):** Papillary > Follicular > Medullary > Anaplastic. * **Psammoma Bodies:** Characteristic of Papillary carcinoma (concentric calcifications). * **Diagnosis:** PTC and Medullary can be diagnosed via FNAC; Follicular carcinoma **cannot** be diagnosed by FNAC (requires histology to see capsular/vascular invasion). * **Most common site of distant metastasis in PTC:** Lungs.

Question 1

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:

Accepted Answer

Near total thyroidectomy.

Answer

Subtotal thyroidectomy.

Answer

Total thyroidectomy.

Answer

Hemithyroidectomy.

Question 2

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?

Accepted Answer

Malignant goiter

Answer

Recurrence of lymphoma

Answer

Benign multinodular goiter

Answer

Toxic nodular goiter

Question 3

A 40-year-old woman is found to have a 15-mm nontender thyroid nodule on the right lobe during routine evaluation. She has no prior history of thyroid disease, feels well, and has normal thyroid function tests. There is no associated lymphadenopathy. What is the most appropriate next step in management?

Accepted Answer

Fine needle aspiration (FNA) biopsy

Answer

Thyroid scan

Answer

Repeat assessment in 6 months

Answer

Partial thyroidectomy

Question 4

Which of the following is true regarding parathyroid glands, except?

Accepted Answer

The superior parathyroid glands lie at the level of the upper border of the thyroid cartilage.

Answer

The superior parathyroid glands are located dorsal to the recurrent laryngeal nerve (RLN).

Answer

The inferior parathyroid glands are located ventral to the recurrent laryngeal nerve (RLN).

Answer

The blood supply to the parathyroid glands comes from both the superior and inferior thyroid arteries.

Question 5

Which is the best treatment for the management of malignant pheochromocytoma?

Accepted Answer

I131-MIBG

Answer

Alpha blockers

Answer

Chemotherapy

Answer

Bulk reducing surgery

Question 6

A 30-year-old male has papillary thyroid carcinoma with a nodule less than 3 cm confined to the neck, along with 2 palpable lymph nodes in the neck and micro-metastasis in the lungs. According to the AJCC 8th edition, how would you stage this patient?

Accepted Answer

Stage II

Answer

Stage I

Answer

Stage III

Answer

Stage IV

Question 7

Which of the following is NOT a characteristic of medullary carcinoma of the thyroid?

Accepted Answer

TSH dependent

Answer

Contains amyloid

Answer

Secretes calcitonin

Answer

Patients should be screened for RET point mutation on chromosome 10

Question 8

What is the most common life-threatening complication of thyroidectomy?

Accepted Answer

Haemorrhage

Answer

Tracheal collapse

Answer

Laryngeal edema

Answer

Bilateral vocal cord palsy

Question 9

Which of the following statements about hyperparathyroidism is FALSE?

Accepted Answer

It commonly occurs after thyroidectomy.

Answer

It may cause hypercalcemia.

Answer

Solitary adenoma is the most common cause.

Answer

None of the above.

Question 10

Which type of thyroid cancer is considered the least malignant?

Accepted Answer

Papillary carcinoma

Answer

Follicular carcinoma

Answer

Medullary carcinoma

Answer

Anaplastic carcinoma

Endocrine Surgery — MCQs

Endocrine Surgery — MCQs

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