Endocrine Surgery Practice Questions

Q: What is the initial preferred investigation for a thyroid nodule?

Thyroid function test. The evaluation of a thyroid nodule follows a systematic diagnostic algorithm. The **initial preferred investigation** is a **Thyroid Function Test (TFT)**, specifically measuring Serum TSH levels. ### Why Thyroid Function Test (TFT) is the correct answer: The primary goal of the initial step is to determine the functional status of the nodule. * If **TSH is suppressed (low)**, it suggests a hyperfunctioning ("hot") nodule, which is rarely malignant. This directs the clinician toward a radionuclide scan. * If **TSH is normal or elevated**, the risk of malignancy is higher, and the next step is typically an Ultrasound followed by FNAC if indicated. Starting with TSH ensures that patients with functional nodules do not undergo unnecessary invasive procedures like FNAC. ### Why other options are incorrect: * **Ultrasound (USG):** While USG is the most sensitive tool for characterizing the anatomy and suspicious features (e.g., microcalcifications, irregular margins), it is usually performed concurrently with or immediately after the TSH result is known. * **Fine Needle Aspiration Cytology (FNAC):** This is the **gold standard** for diagnosing malignancy, but it is not the *initial* step. It is performed only after confirming the nodule is non-functional. * **Radionuclide Scan:** This is indicated only if the TSH is low. It is no longer a routine first-line test for all nodules. ### High-Yield Clinical Pearls for NEET-PG: * **Best Initial Test:** Serum TSH (TFT). * **Most Accurate/Gold Standard:** FNAC. * **First Imaging Modality:** Ultrasound. * **FNAC Contraindication:** FNAC should not be performed in a "Hot Nodule" (risk of bleeding and low diagnostic yield as hot nodules are almost always benign). * **Follicular Carcinoma:** FNAC cannot distinguish between follicular adenoma and carcinoma; histopathology (showing capsular or vascular invasion) is required.

Q: Which of the following statements regarding anaplastic carcinoma is FALSE?

Radiotherapy cures it.. Anaplastic Thyroid Carcinoma (ATC) is one of the most aggressive and lethal solid tumors in humans. Understanding its clinical behavior is crucial for NEET-PG. ### **Why Option D is False (The Correct Answer)** Anaplastic carcinoma is notorious for its **extreme resistance** to all conventional treatment modalities, including surgery, chemotherapy, and radiotherapy. While radiotherapy (often combined with chemotherapy) is used for **palliative local control** to prevent airway obstruction, it is **not curative**. The prognosis remains dismal, with a median survival of only 3–6 months. ### **Explanation of Other Options** * **Option A (Common in the elderly):** True. ATC typically presents in the 6th to 7th decades of life. It is rare in patients under 50. * **Option B (Associated with P53 mutation):** True. Molecular pathogenesis often involves the inactivation of the **TP53 tumor suppressor gene**, which is a hallmark of its dedifferentiation from well-differentiated thyroid cancers (like papillary or follicular). * **Option C (Surrounding neck tissue is usually infiltrated):** True. ATC is characterized by rapid local invasion. Patients often present with a "woody hard" fixed neck mass, causing dysphagia, hoarseness (recurrent laryngeal nerve palsy), and dyspnea due to infiltration of the esophagus, larynx, and trachea. ### **Clinical Pearls for NEET-PG** * **Presentation:** Rapidly enlarging neck mass in an elderly patient. * **Diagnosis:** Core needle biopsy or FNA; histology shows spindle, giant, or squamoid cells. * **Staging:** According to AJCC, all Anaplastic carcinomas are classified as **Stage IV** at the time of diagnosis. * **Treatment:** Primarily palliative. If the disease is resectable (rare), total thyroidectomy followed by adjuvant chemoradiotherapy is attempted.

Q: An 80-year-old male presents with a rapidly enlarging neck mass and hoarseness of voice. He has a history of untreated papillary carcinoma of the thyroid. What is the likely diagnosis?

Anaplastic thyroid cancer. **Explanation:** The clinical presentation of an elderly patient with a **rapidly enlarging neck mass**, hoarseness (suggesting recurrent laryngeal nerve palsy), and a history of untreated differentiated thyroid cancer (DTC) is a classic "textbook" description of **Anaplastic Thyroid Cancer (ATC)**. **1. Why Anaplastic Thyroid Cancer is correct:** ATC is one of the most aggressive solid tumors. It typically occurs in the 7th–8th decades of life. Crucially, up to **20–30% of ATC cases arise from pre-existing differentiated thyroid cancers** (like Papillary or Follicular carcinoma) through a process of dedifferentiation. The rapid growth leads to compressive symptoms (dyspnea, dysphagia) and local invasion (hoarseness). **2. Why the other options are incorrect:** * **Medullary Thyroid Cancer (MTC):** Arises from parafollicular C-cells. While it can be aggressive, it does not typically present with this degree of explosive growth or arise from a prior papillary carcinoma. * **Hürthle Cell Carcinoma:** A variant of follicular cancer. While more aggressive than standard DTC, it follows a much slower clinical course than ATC. * **Papillary Thyroid Cancer (PTC):** This is the most common thyroid malignancy and generally has an excellent prognosis with slow growth. The sudden change in behavior in an 80-year-old indicates transformation rather than the primary PTC itself. **Clinical Pearls for NEET-PG:** * **Most common site of metastasis:** Lungs (often present at diagnosis). * **Histology:** Shows spindle cells, giant cells, or squamoid cells; IHC is often positive for **PAX-8**. * **Prognosis:** Extremely poor; most patients have Stage IV disease at presentation. * **Key Differential:** Thyroid Lymphoma (also presents as a rapidly enlarging mass, but usually associated with Hashimoto’s thyroiditis).

Q: Goiter that appears along with toxic symptoms is classified as:

Primary thyrotoxicosis. In endocrine surgery, the classification of thyrotoxicosis is based on the chronological relationship between the appearance of the goiter and the onset of toxic symptoms. ### **Explanation of the Correct Answer** **A. Primary Thyrotoxicosis:** This is defined as a condition where the **goiter and toxic symptoms appear simultaneously**. The most common cause is **Graves' Disease**, an autoimmune disorder where TSH-receptor antibodies stimulate the entire gland. Clinically, the goiter is typically diffuse, vascular, and associated with extrathyroidal manifestations like exophthalmos and pretibial myxedema. ### **Why Other Options are Incorrect** * **B. Secondary Thyrotoxicosis:** This occurs when toxic symptoms develop in a patient who has had a **pre-existing long-standing simple goiter** (usually for many years). It is typically seen in **Toxic Multinodular Goiter (Plummer’s Disease)**. Unlike primary thyrotoxicosis, it rarely presents with exophthalmos. * **C. Toxic Nodule:** This refers to a single autonomous hyperfunctioning nodule (solitary toxic adenoma) within an otherwise normal or suppressed gland. While it causes thyrotoxicosis, the term "Primary Thyrotoxicosis" is the broader, standard classification for the simultaneous onset of goiter and toxicity. ### **NEET-PG High-Yield Pearls** * **Primary Thyrotoxicosis (Graves'):** Diffuse goiter + Toxicity + Eye signs (Exophthalmos). * **Secondary Thyrotoxicosis (TMNG):** Pre-existing nodular goiter + Toxicity + No eye signs + Higher risk of cardiac arrhythmias (Atrial Fibrillation) in elderly patients. * **Marine-Lenhart Syndrome:** The coexistence of Graves' disease with functioning nodules. * **Jod-Basedow Phenomenon:** Iodine-induced hyperthyroidism, often seen when iodine is given to a patient with a pre-existing multinodular goiter.

Q: Most of the incidentalomas are:

Non-functioning adenoma. **Explanation:** An **adrenal incidentaloma** is defined as an adrenal mass (≥1 cm) discovered serendipitously during radiologic imaging performed for reasons other than suspected adrenal disease. **1. Why Non-functioning Adenoma is Correct:** The vast majority of incidentalomas (approximately **75–80%**) are **clinically silent, non-functioning cortical adenomas**. These are benign lesions that do not secrete hormones in excess. Because they lack clinical symptoms, they remain undetected until imaging is performed for unrelated abdominal or thoracic complaints. **2. Analysis of Incorrect Options:** * **Adrenocortical Carcinoma (ACC):** While a critical diagnosis to exclude, primary malignancy is rare, accounting for less than 5% of incidentalomas. Size (>4 cm) and imaging characteristics (high Hounsfield units) are used to screen for this. * **Adrenal Metastasis:** These are common in patients with a *known* primary malignancy (e.g., lung or breast cancer), but in the general population presenting with an incidentaloma, benign adenomas are far more frequent. * **Pheochromocytoma:** These account for only about 5% of incidentalomas. However, because they can be life-threatening if missed, all patients with an incidentaloma must undergo biochemical screening (plasma or urinary metanephrines) regardless of symptoms. **Clinical Pearls for NEET-PG:** * **Initial Workup:** Every incidentaloma requires two assessments: **Hormonal activity** (Rule out Pheochromocytoma, Cushing’s, and Conn’s) and **Malignancy risk** (Size and CT attenuation). * **High-Yield Cut-off:** Lesions **>4 cm** or those with **CT attenuation >10 HU** (non-contrast) are suspicious for malignancy and often warrant surgical resection (Adrenalectomy). * **Most common functioning incidentaloma:** Subclinical Cushing’s syndrome (Autonomous Cortisol Secretion).

Q: Compared to follicular carcinoma, papillary carcinoma of the thyroid has which of the following features?

Bilaterality. **Explanation:** The correct answer is **Bilaterality**. Papillary Thyroid Carcinoma (PTC) is the most common thyroid malignancy and is characterized by its **multicentricity**. In approximately 20–80% of cases (depending on the study), PTC is found to be multifocal or bilateral within the thyroid gland, often due to intraglandular lymphatic spread. In contrast, Follicular Thyroid Carcinoma (FTC) is typically a solitary, encapsulated lesion. **Analysis of Options:** * **A. More male preponderance:** Incorrect. Both PTC and FTC are significantly more common in females (roughly a 3:1 ratio). * **C. Local recurrence is common:** Incorrect. While PTC can recur, it is generally considered to have an excellent prognosis with low recurrence rates if managed correctly. FTC, due to its hematogenous spread, often presents with distant metastases (bone/lung) rather than just local recurrence. * **D. Increased mortality:** Incorrect. PTC has a much better prognosis than FTC. The 10-year survival rate for PTC is >90%, whereas FTC has a higher mortality rate due to its tendency for early vascular invasion and distant spread. **NEET-PG High-Yield Pearls:** * **Spread:** PTC spreads via **lymphatics** (leads to "lateral aberrant thyroid" or cervical nodes); FTC spreads via **blood** (hematogenous). * **Histology (PTC):** Look for **Orphan Annie eye nuclei**, Psammoma bodies, and nuclear grooves. * **Diagnosis:** PTC can be diagnosed via FNAC; FTC **cannot** be diagnosed by FNAC (requires histological proof of capsular or vascular invasion). * **Risk Factor:** Prior radiation exposure is a major risk factor for PTC.

Q: A professional singer presents with difficulty in raising the pitch of her voice following thyroid surgery. There is no hoarseness, but high-pitched voice production is impaired. Which nerve is most likely injured?

External branch of the superior laryngeal nerve (EBSLN). ***Correct: External branch of the superior laryngeal nerve (EBSLN)*** - The EBSLN innervates the **cricothyroid muscle**, which is responsible for increasing **vocal cord tension** - Injury results in inability to tense the vocal cords, causing **loss of high-pitched voice** production - Crucially, there is **NO hoarseness** because vocal cord adduction (brought together by other muscles) remains intact - Classic presentation: Professional singers or teachers notice difficulty hitting high notes after thyroid surgery *Incorrect: Recurrent laryngeal nerve (RLN)* - RLN innervates all intrinsic laryngeal muscles **except** the cricothyroid - Injury causes **hoarseness** due to impaired vocal cord adduction - This patient has no hoarseness, making RLN injury unlikely *Incorrect: Internal branch of the superior laryngeal nerve (IBSLN)* - IBSLN is purely **sensory** to the supraglottic larynx - Injury causes loss of sensation above the vocal cords, leading to **aspiration risk** - Does not affect voice pitch or motor function *Incorrect: Glossopharyngeal nerve* - Provides motor innervation to stylopharyngeus and sensory to pharynx/posterior tongue - **Not involved in laryngeal function** or voice production - Injury would cause dysphagia and loss of gag reflex, not voice changes

Question 1

What is the initial preferred investigation for a thyroid nodule?

Accepted Answer

Thyroid function test

Answer

Fine Needle Aspiration Cytology (FNAC)

Answer

Radionuclide scan

Answer

Ultrasound (USG)

Question 2

Which of the following statements regarding anaplastic carcinoma is FALSE?

Accepted Answer

Radiotherapy cures it.

Answer

It is common in the elderly.

Answer

It is associated with P53 mutation.

Answer

Surrounding neck tissue is usually infiltrated.

Question 3

A 75-year-old woman presents with mild congestive heart failure 6 weeks after a myocardial infarction. She has a past history of neck surgery for parathyroid adenoma 5 years ago. ECG shows slow atrial fibrillation. Serum calcium is 13.0 mg/dL and urinary calcium is 300 mg/24 hr. On examination, there is a small mass in the paratracheal position behind the right clavicle. What is the most appropriate management at this time?

Accepted Answer

Ultrasound-guided ethanol injection of the mass

Answer

Repeat neck surgery

Answer

Treatment with technetium-99 sestamibi scan

Answer

Observation and repeat serum calcium in two months

Question 4

An 80-year-old male presents with a rapidly enlarging neck mass and hoarseness of voice. He has a history of untreated papillary carcinoma of the thyroid. What is the likely diagnosis?

Accepted Answer

Anaplastic thyroid cancer

Answer

Medullary thyroid cancer

Answer

Hürthle cell carcinoma

Answer

Papillary thyroid cancer

Question 5

Goiter that appears along with toxic symptoms is classified as:

Accepted Answer

Primary thyrotoxicosis

Answer

Secondary thyrotoxicosis

Answer

Toxic nodule

Answer

None of the above

Question 6

During bilateral adrenalectomy, what is the appropriate timing for intraoperative hydrocortisone administration?

Accepted Answer

Excision of both adrenal glands

Answer

Opening the abdomen

Answer

Ligation of the left adrenal vein

Answer

Ligation of the right adrenal vein

Question 7

A 30-year-old female patient presents with a complaint of a painless, hard anterior neck mass. Fine Needle Aspiration Cytology (FNAC) was inconclusive. An open thyroid biopsy was performed, which revealed a fibrous, woody, non-tender thyroid mass, mimicking carcinoma. What is the most likely diagnosis?

Accepted Answer

Riedel's thyroiditis

Answer

De Quervain's thyroiditis

Answer

Hashimoto's thyroiditis

Answer

None of the above

Question 8

Most of the incidentalomas are:

Accepted Answer

Non-functioning adenoma

Answer

Adrenocortical carcinoma

Answer

Adrenal metastasis

Answer

Pheochromocytoma

Question 9

Compared to follicular carcinoma, papillary carcinoma of the thyroid has which of the following features?

Accepted Answer

Bilaterality

Answer

More male preponderance

Answer

Local recurrence is common

Answer

Increased mortality

Question 10

A professional singer presents with difficulty in raising the pitch of her voice following thyroid surgery. There is no hoarseness, but high-pitched voice production is impaired. Which nerve is most likely injured?

Accepted Answer

External branch of the superior laryngeal nerve (EBSLN)

Answer

Glossopharyngeal nerve

Answer

Internal branch of the superior laryngeal nerve (IBSLN)

Answer

Recurrent laryngeal nerve (RLN)

Endocrine Surgery — MCQs

Endocrine Surgery — MCQs

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