Endocrine Surgery Practice Questions

Q: Which of the following is NOT a true statement about papillary carcinoma?

Hematogenous spread is common.. **Explanation:** Papillary Thyroid Carcinoma (PTC) is the most common type of thyroid malignancy. The hallmark of PTC is its tendency for **lymphatic spread** rather than hematogenous spread. 1. **Why Option C is the correct (False) statement:** Unlike Follicular Thyroid Carcinoma, which characteristically spreads via the bloodstream (hematogenous), Papillary Carcinoma primarily spreads through the lymphatics to the cervical lymph nodes. While hematogenous spread can occur, it is **uncommon** (occurring in <5-10% of cases). Therefore, stating it is "common" is incorrect. 2. **Analysis of other options:** * **Option A (Radiation):** Exposure to ionizing radiation (especially during childhood) is the most well-established environmental risk factor for PTC. * **Option B (Multifocal):** PTC is frequently multifocal (involving multiple sites within the gland) and bilateral in up to 20-80% of cases, which often influences the decision for total thyroidectomy. * **Option D (Distant metastasis):** Although rare compared to lymphatic spread, distant metastasis can occur, most commonly involving the **lungs** (often presenting as a miliary pattern) and occasionally the bones. **NEET-PG High-Yield Pearls:** * **Most common** thyroid cancer overall and most common after radiation exposure. * **Microscopic Hallmarks:** Psammoma bodies (calcified laminations), Orphan Annie eye nuclei (clear nuclei), and nuclear grooves. * **Prognosis:** Generally excellent; the **AMES** (Age, Metastasis, Extent, Size) and **MACIS** scores are used for staging. * **BRAF Mutation:** The most common genetic mutation associated with PTC.

Q: Compared to follicular carcinoma, papillary carcinoma of the thyroid is associated with which of the following?

Radiation exposure. **Explanation:** The correct answer is **Radiation exposure**. Papillary Thyroid Carcinoma (PTC) is the most common thyroid malignancy and has a strong, well-documented association with prior exposure to ionizing radiation (e.g., childhood neck irradiation or nuclear accidents). In contrast, Follicular Thyroid Carcinoma (FTC) is more closely linked to dietary factors. **Analysis of Options:** * **Radiation Exposure (Correct):** Ionizing radiation is a major risk factor for PTC, often involving mutations in the *RET/PTC* rearrangement or *BRAF* gene. * **More Male Preponderance (Incorrect):** Both PTC and FTC are significantly more common in females (approx. 3:1 ratio). There is no male preponderance for PTC. * **Iodine Deficiency (Incorrect):** This is a classic risk factor for **Follicular Carcinoma** and Anaplastic Carcinoma. In contrast, iodine-rich areas often see a higher relative incidence of Papillary Carcinoma. * **Increased Mortality (Incorrect):** PTC has an excellent prognosis with a 10-year survival rate exceeding 90-95%. FTC is generally more aggressive than PTC due to its tendency for early hematogenous spread (to bone and lungs), whereas PTC primarily spreads via lymphatics. **High-Yield Clinical Pearls for NEET-PG:** * **Psammoma Bodies:** Laminated calcifications pathognomonic for PTC (found in 50% of cases). * **Orphan Annie Eye Nuclei:** Characteristic clear/ground-glass nuclei seen in PTC. * **Spread:** PTC spreads **Lymphatically** (most common site: Level VI nodes); FTC spreads **Hematogenously**. * **Diagnosis:** PTC can be diagnosed via FNAC (nuclear features); FTC **cannot** be diagnosed by FNAC (requires histological proof of capsular or vascular invasion).

Q: Which of the following is FALSE regarding medullary carcinoma of the thyroid?

It is familial in 90% of cases.. **Explanation:** Medullary Thyroid Carcinoma (MTC) is a unique neuroendocrine tumor. The correct answer is **D** because the statement is factually reversed: **75–80% of MTC cases are sporadic**, while only **20–25% are familial** (associated with MEN 2A, MEN 2B, or Familial MTC). * **Option A (Incorrect):** Calcitonin is the primary tumor marker for MTC. It is used for diagnosis, screening of family members, and monitoring recurrence. Carcinoembryonic antigen (CEA) is also used as a secondary marker. * **Option B (Incorrect):** MTC arises from the **Parafollicular C-cells**, which are derived from the **ultimobranchial body** (neural crest origin). Unlike papillary or follicular cancers, MTC does not arise from follicular cells and thus does not concentrate iodine. * **Option C (Incorrect):** The **RET proto-oncogene** mutation is the hallmark of MTC. It is present in nearly 100% of familial cases (germline mutation) and approximately 50% of sporadic cases (somatic mutation). **High-Yield Clinical Pearls for NEET-PG:** * **Amyloid Stroma:** Histology typically shows nests of cells with "apple-green birefringence" on Congo Red staining due to procalcitonin deposition. * **Management:** The treatment of choice is **Total Thyroidectomy with Central Compartment Neck Dissection**. * **Screening:** In patients with known RET mutations, prophylactic thyroidectomy is recommended (at age 5 for MEN 2A and infancy for MEN 2B). * **Rule out Pheochromocytoma:** Always screen for pheochromocytoma before surgery in familial cases to prevent a hypertensive crisis during anesthesia.

Q: Which type of carcinoma most commonly arises in a thyroglossal cyst?

Papillary. **Explanation:** A thyroglossal duct cyst (TGDC) is the most common congenital neck swelling, resulting from a failure of the thyroglossal duct to obliterate. While malignancy is rare (occurring in <1% of cases), when it does occur, it is almost always of thyroid follicular cell origin. **1. Why Papillary Carcinoma is Correct:** **Papillary Thyroid Carcinoma (PTC)** accounts for approximately **85–90%** of all malignancies arising in a thyroglossal cyst. The reason is attributed to the presence of ectopic thyroid tissue within the cyst wall. Since PTC is the most common type of thyroid cancer in the general population, it is also the most frequent histological subtype found in these remnants. **2. Why Other Options are Incorrect:** * **Follicular Carcinoma:** While it arises from follicular cells, it is significantly less common than PTC in this location (approx. 5–7%). * **Medullary Carcinoma:** This arises from **Parafollicular C-cells**, which are derived from the **ultimobranchial body** (4th branchial pouch), not the thyroglossal duct. Therefore, Medullary carcinoma is virtually never found in a TGDC. * **Anaplastic Carcinoma:** This is an extremely rare, undifferentiated tumor. While theoretically possible, it is not the "most common." **3. NEET-PG High-Yield Pearls:** * **Sistrunk Operation:** The definitive surgical treatment for TGDC, involving excision of the cyst, the entire duct, and the **central portion of the hyoid bone** to prevent recurrence. * **Diagnosis:** Often an incidental finding on histopathology after a Sistrunk procedure. * **Management of Malignancy:** If a TGDC contains PTC, a Sistrunk procedure is often sufficient if the thyroid gland itself is normal on ultrasound. Total thyroidectomy is considered if there are suspicious nodules in the main thyroid gland or cervical lymphadenopathy.

Q: A male patient in a euthyroid state presents with which of the following conditions?

Multiple nodular goiter. ### Explanation **1. Why Multiple Nodular Goiter (MNG) is the Correct Answer:** In the context of standard surgical presentations, **Multinodular Goiter (MNG)** is the classic example of a thyroid swelling where the patient typically remains in a **euthyroid state**. The pathophysiology involves cycles of hyperplasia and involution due to fluctuating TSH levels or iodine deficiency, leading to thyroid enlargement without necessarily causing functional overactivity. While some MNGs can become toxic (Plummer’s disease), the vast majority encountered in clinical practice and exams are "non-toxic" or euthyroid. **2. Analysis of Incorrect Options:** * **Thyroglossal Cyst (Option A):** While patients are usually euthyroid, this is a **developmental anomaly** (persistent thyroglossal duct) rather than a primary thyroid gland pathology. It is often midline and moves with protrusion of the tongue. * **Solitary Thyroid Nodule (Option C):** A solitary nodule can be euthyroid, but it carries a higher risk of **malignancy** (approx. 5-15%) or may be a "hot" toxic nodule. MNG is a more definitive clinical representation of a benign euthyroid enlargement. * **Toxic Nodular Goiter (Option D):** By definition, "toxic" implies **hyperthyroidism**. These patients present with suppressed TSH and elevated T3/T4 levels, manifesting clinical symptoms like tachycardia and tremors. **3. Clinical Pearls for NEET-PG:** * **Most common cause of goiter worldwide:** Iodine deficiency. * **Pemberton’s Sign:** Used to detect retrosternal extension in MNG; look for facial flushing and inspiratory stridor upon raising both arms. * **Investigation of Choice:** FNAC is the gold standard for evaluating nodules within an MNG to rule out malignancy (Dominant nodule). * **Treatment:** For euthyroid MNG, surgery (Total Thyroidectomy) is indicated only if there are pressure symptoms, retrosternal extension, or cosmetic concerns.

Q: A 30-year-old pregnant woman presents with a history of thyroid swelling. FNAC report shows papillary carcinoma of the thyroid, and the nodule was cold on radioiodine uptake scan. Which of the following is NOT a treatment option?

Thyroidectomy. **Explanation:** The core concept in this question is the **contraindication of radioactive substances during pregnancy**. **Why Option D (Radioiodine ablation) is the correct answer (NOT an option):** Radioactive Iodine (I-131) is strictly contraindicated during pregnancy. It crosses the placenta and can be concentrated by the fetal thyroid gland (which begins functioning at 10–12 weeks of gestation), leading to **fetal hypothyroidism**, thyroid destruction, and potential teratogenic effects. Additionally, the radioiodine uptake scan mentioned in the stem is typically avoided in pregnancy; diagnosis is usually made via ultrasound and FNAC. **Why the other options are incorrect (They ARE treatment options):** * **A, B, and C (Surgical options):** Surgery is the mainstay of treatment for Papillary Thyroid Carcinoma (PTC) during pregnancy. If diagnosed in the 1st or 2nd trimester, surgery is ideally performed during the **2nd trimester** (when organogenesis is complete and the risk of preterm labor is lowest). If diagnosed in the 3rd trimester, surgery can often be deferred until the postpartum period unless the disease is rapidly progressive. Depending on the size and extent of the tumor, a Lobectomy, Hemithyroidectomy, or Total Thyroidectomy can be safely performed. **High-Yield Clinical Pearls for NEET-PG:** * **Most common thyroid cancer in pregnancy:** Papillary Carcinoma. * **Safe window for surgery:** 2nd Trimester (specifically before 24 weeks). * **I-131 and Breastfeeding:** Also contraindicated; it is secreted in breast milk. * **Suppressive Therapy:** If surgery is deferred until postpartum, the patient is started on **L-Thyroxine** to keep TSH levels low (0.1–0.5 mU/L) to prevent tumor growth.

Q: What serum marker is used after surgery for differentiated thyroid cancer?

Thyroglobulin. **Explanation:** **Thyroglobulin (Tg)** is the correct answer because it serves as a highly specific tumor marker for **Differentiated Thyroid Cancer (DTC)**, which includes Papillary and Follicular carcinomas. 1. **Why Thyroglobulin?** Tg is a glycoprotein produced exclusively by follicular cells of the thyroid. After a total thyroidectomy and radioactive iodine (RAI) ablation, there should be no remaining thyroid tissue. Therefore, any detectable serum Tg during follow-up indicates persistent or recurrent disease. It is often measured alongside **Anti-thyroglobulin antibodies (anti-TgAb)**, as their presence can falsely lower Tg readings. 2. **Why the others are incorrect:** * **T4 (Thyroxine):** This is a hormone used for replacement therapy post-surgery, not a marker for recurrence. * **Calcitonin:** This is the specific tumor marker for **Medullary Thyroid Cancer (MTC)**, which arises from parafollicular C-cells, not DTC. * **PTH (Parathyroid Hormone):** This is monitored post-thyroidectomy to check for accidental damage or removal of the parathyroid glands (hypoparathyroidism), but it is not a cancer marker. **High-Yield Clinical Pearls for NEET-PG:** * **Stimulated Tg:** Tg levels are most sensitive when TSH is high (either by stopping T4 or giving recombinant TSH). * **Mnemonic:** **M**edullary = **M**arker is Calcitonin; **D**ifferentiated = **D**etected by Thyroglobulin. * **Hurthle Cell Carcinoma:** Also uses Thyroglobulin as a marker. * **Anaplastic Carcinoma:** Does not have a reliable serum marker as the cells are too undifferentiated to produce Tg.

Question 1

Which of the following is NOT a true statement about papillary carcinoma?

Accepted Answer

Hematogenous spread is common.

Answer

Radiation is a risk factor.

Answer

It can be multifocal.

Answer

Distant metastasis is seen.

Question 2

A patient with long-standing multinodular goitre develops hoarseness of voice, and the swelling undergoes a sudden increase in size. What is the likely diagnosis?

Accepted Answer

Follicular carcinoma

Answer

Papillary carcinoma

Answer

Medullary carcinoma

Answer

Anaplastic carcinoma

Question 3

In which type of thyroid carcinoma is treatment with radioactive iodine (1-131) most beneficial?

Accepted Answer

Follicular carcinoma

Answer

Papillary carcinoma

Answer

Anaplastic carcinoma

Answer

Medullary carcinoma

Question 4

Compared to follicular carcinoma, papillary carcinoma of the thyroid is associated with which of the following?

Accepted Answer

Radiation exposure

Answer

More male preponderance

Answer

Iodine deficiency

Answer

Increased mortality

Question 5

What is true regarding incidental adrenal masses?

Accepted Answer

May represent adrenocortical carcinoma if greater than 6 cm in diameter.

Answer

May be seen in as many as 10% of abdominal CT studies.

Answer

Most commonly represent pheochromocytoma; adrenocortical adenoma, adrenocortical carcinoma, and metastases from other primary cancers occur less frequently.

Answer

Should be routinely evaluated by measurement of 24-hour urine levels of catecholamines and their metabolites, cortisol, and aldosterone plus fine-needle aspiration.

Question 6

Which of the following is FALSE regarding medullary carcinoma of the thyroid?

Accepted Answer

It is familial in 90% of cases.

Answer

The tumor marker is calcitonin.

Answer

It arises from parafollicular cells.

Answer

It is associated with RET mutations.

Question 7

Which type of carcinoma most commonly arises in a thyroglossal cyst?

Accepted Answer

Papillary

Answer

Follicular

Answer

Medullary

Answer

Anaplastic

Question 8

A male patient in a euthyroid state presents with which of the following conditions?

Accepted Answer

Multiple nodular goiter

Answer

Thyroglossal cyst

Answer

Solitary thyroid nodule

Answer

Toxic nodular goiter

Question 9

A 30-year-old pregnant woman presents with a history of thyroid swelling. FNAC report shows papillary carcinoma of the thyroid, and the nodule was cold on radioiodine uptake scan. Which of the following is NOT a treatment option?

Accepted Answer

Thyroidectomy

Answer

Right-sided hemithyroidectomy

Answer

Lobectomy

Answer

Radioiodine ablation of the thyroid

Question 10

What serum marker is used after surgery for differentiated thyroid cancer?

Accepted Answer

Thyroglobulin

Answer

T4

Answer

Calcitonin

Answer

PTH

Endocrine Surgery — MCQs

Endocrine Surgery — MCQs

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