Endocrine Surgery Practice Questions

Q: Which metastases are most common to the thyroid?

Kidney. ***Kidney (Renal Cell Carcinoma)*** - **Renal cell carcinoma** is the most common primary tumor to metastasize to the thyroid gland, accounting for approximately 30-50% of all thyroid metastases. - Thyroid metastases from renal cancer are often **hypervascular** and may present as rapidly growing thyroid nodules. - These metastases typically indicate advanced disease and occur in the setting of widespread metastatic involvement. *Lung* - **Lung cancer** is the second most common source of thyroid metastases, particularly small cell and non-small cell carcinoma. - Lung cancer metastases to the thyroid usually occur in patients with known disseminated disease. - These are often identified incidentally during imaging or at autopsy. *Breast* - **Breast cancer** is the third most common primary tumor to metastasize to the thyroid. - Lobular carcinoma of the breast shows a higher propensity for thyroid metastases compared to ductal carcinoma. - Presentation is typically in the context of widespread metastatic disease. *GIT* - **Gastrointestinal (GIT) cancers**, including colorectal and gastric cancers, are uncommon sources of thyroid metastases. - When present, GIT metastases to the thyroid signify advanced disease with multiple organ involvement. - These are rare and usually discovered incidentally during evaluation for other metastatic sites.

Q: Hypoparathyroidism following thyroid surgery occurs within:

24 hours. ***24 hours*** - **Symptomatic hypocalcemia** from hypoparathyroidism typically **begins within 24 hours** and peaks at **24-48 hours** post-thyroidectomy. - Serum calcium levels start to decline within the **first 24 hours** as parathyroid hormone (PTH) production decreases due to surgical trauma, ischemia, or inadvertent removal/damage to parathyroid glands. - Most patients who develop clinically significant hypoparathyroidism show **early signs** including perioral numbness, paresthesias, and positive Chvostek's or Trousseau's signs within this timeframe. - **Early monitoring** of calcium levels (usually at 6-12 hours postoperatively) is standard practice to detect and treat hypocalcemia promptly. *2 - 5 days* - While some cases may continue to worsen during this period, the **onset** typically occurs much earlier (within 24-48 hours). - This timeframe represents continuation or persistence of hypocalcemia rather than initial manifestation. - Waiting 2-5 days to detect hypoparathyroidism would be considered delayed diagnosis in modern practice. *7-14 days* - This timeframe is **too late** for acute postoperative hypoparathyroidism diagnosis. - By this time, the focus shifts to determining whether hypoparathyroidism is **transient** (resolving within 6 months) or **permanent**. - Most acute symptomatic cases have already been identified and are under treatment by this period. *2 - 3 weeks* - Hypoparathyroidism presenting at **2-3 weeks** would be highly unusual for post-thyroidectomy complications. - At this stage, clinicians are assessing for **recovery of parathyroid function** rather than initial onset. - **Permanent hypoparathyroidism** is only diagnosed if hypocalcemia persists beyond **6 months**, not at 2-3 weeks.

Q: Which of the following factors is not included in the MACIS score used for the prognosis of papillary thyroid cancer?

Mitotic index. ***Mitotic index*** - The MACIS score is a **prognostic scoring system** for papillary thyroid carcinoma, and the mitotic index is **not a component** of this score. - The MACIS score considers factors such as **Metastasis**, **Age**, **Completeness of excision**, **Invasion**, and **Size** of the tumor. *Age* - **Age** is a crucial factor in the MACIS score, with patients older than 40 years typically having a **worse prognosis**. - It differentiates between patients <40 years and ≥40 years, assigning different points based on age. *Size* - The **size** of the primary tumor is an important component of the MACIS score. - Tumors larger than 4 cm (or 40 mm) are associated with a **higher score** and a less favorable prognosis. *Excision completion in surgery* - The **completeness of surgical excision** is a critical factor in the MACIS score. - **Incomplete tumor removal** or gross residual tumor after surgery indicates a worse prognosis and adds points to the score.

Q: Which of the following is NOT a classification of retrosternal goiter?

Nodular goiter.. ***Nodular goiter*** - **Nodular goiter** describes the *morphology* of the thyroid gland (presence of nodules), not its anatomical location in relation to the sternum. - While a retrosternal goiter can certainly be nodular, "nodular goiter" itself is a description of the gland's structure rather than a classification of its retrosternal extension. *Substernal* - **Substernal goiter** is a common and interchangeable term for a retrosternal goiter, denoting its location partially or entirely *behind the sternum*. - This classification specifically describes the anatomical extension of the thyroid gland. *Plunging* - **Plunging goiter** refers to a thyroid gland that intermittently or permanently descends into the thoracic cavity, often exacerbated by a swallow or Valsalva maneuver. - This term highlights the dynamic movement characteristic of some retrosternal goiters. *Intrathoracic* - **Intrathoracic goiter** is another term used to describe a goiter located within the chest cavity, emphasizing its *position relative to the thoracic inlet*. - This classification is synonymous with retrosternal or substernal goiter, indicating its anatomical deep extension.

Q: Most common injured nerve after thyroidectomy is?

Recurrent laryngeal nerve. ***Recurrent laryngeal nerve*** - The **recurrent laryngeal nerves (RLNs)** are most frequently injured during thyroidectomy due to their close proximity to the thyroid gland and their variable anatomical course. - Injury to the RLN can result in **vocal cord paralysis**, causing hoarseness or aphonia. *External laryngeal nerve* - The **external laryngeal nerve (ELN)** is a branch of the superior laryngeal nerve and innervates the **cricothyroid muscle**, which tenses the vocal cords. - While it can be injured during thyroidectomy, especially during high ligation of the superior thyroid artery, it is less commonly injured than the recurrent laryngeal nerve. *Superior laryngeal nerve* - The **superior laryngeal nerve (SLN)** branches into the internal and external laryngeal nerves. While portions of the SLN or its branches (ELN) can be injured, the entire SLN is less commonly damaged than the recurrent laryngeal nerve. - Injury to the internal laryngeal nerve would affect sensation above the vocal cords, and injury to the external laryngeal nerve would affect pitch control. *Nerve to omohyoid* - The omohyoid muscle is a strap muscle in the neck, innervated by the **ansa cervicalis**, a branch of the cervical plexus. - This nerve is located far from the thyroid gland's surgical field and is therefore **very rarely injured** during a thyroidectomy.

Q: A patient diagnosed with papillary carcinoma of the thyroid underwent a whole-body iodine scan six weeks after surgery, which revealed residual disease. The next best step is:

Radioiodine ablation. ***Radioiodine ablation*** - **Radioiodine (RAI) ablation** is the standard treatment for residual thyroid cancer after surgery, especially for **papillary thyroid carcinoma**, which typically avidly takes up iodine. - The goal is to destroy any remaining microscopic thyroid cells or cancer cells that may not have been removed surgically. - This is the **next best step** when residual disease is detected on whole-body iodine scan. *Surgical removal of residual disease* - While surgical removal is a primary treatment, attempting another surgery for **microscopic residual disease** detected by a whole-body scan might be difficult and carry higher risks. - RAI ablation is generally preferred for **diffuse residual disease** or microscopic foci that are not amenable to surgical resection. *FNAC of the residual tissue followed by radioiodine ablation* - **Fine needle aspiration cytology (FNAC)** typically targets discrete nodules, and the whole-body scan indicates diffuse or multifocal residual tissue, making FNAC less practical. - Since the diagnosis of **papillary carcinoma** is already established histologically, re-biopsy of residual tissue is unnecessary before RAI ablation, especially if the residual disease is diffuse. - This would cause unnecessary delay in definitive treatment. *Neck ultrasound and serum thyroglobulin level measurement* - These are **diagnostic and monitoring tools**, not definitive treatments for established residual disease. - While crucial for initial evaluation and ongoing surveillance, they do not eliminate the residual cancer, which is the immediate priority.

Q: A middle-aged patient presents with a woody-hard thyroid gland that is fixed to surrounding structures and does not move with deglutition. The patient is euthyroid and the condition has been slowly progressive. What is the most likely diagnosis?

Reidel's thyroiditis.. ***Reidel's thyroiditis*** - This rare condition involves **dense fibrosis** of the thyroid gland, causing it to become **woody-hard** and **fixed to surrounding structures** in the neck. - Key distinguishing features include **slow progression**, **euthyroid status**, and the thyroid gland being **rock-hard** on palpation. - The immobility due to fibrosis prevents the thyroid gland from moving with **deglutition**, a key clinical sign. *Anaplastic thyroid carcinoma* - While this aggressive cancer can also invade surrounding tissues and cause fixation, it presents very differently. - Characterized by **rapid growth** (weeks to months), elderly patients (>60 years), **compressive symptoms**, and often metastatic disease at presentation. - The clinical context of slow progression and euthyroid status makes this less likely. *Retrosternal goitre* - A **retrosternal goitre** is a thyroid enlargement that extends down into the chest behind the sternum. - The portion of the gland within the neck typically **moves with deglutition**, unless there are complications like hemorrhage or malignancy causing fixation. - Not characterized by woody-hard consistency. *None of the options* - This option is incorrect because Reidel's thyroiditis is the condition that best fits the clinical scenario described.

Q: Metastases from follicular carcinoma should be treated by:

Radioiodine. ***Radioiodine*** - **Differentiated thyroid cancers**, including **follicular carcinoma**, retain the ability to uptake iodine, making **radioiodine (I-131) therapy** highly effective for treating metastases [1]. - This therapy targets and destroys thyroid cancer cells wherever they are located in the body, including distant metastatic sites. *Surgery* - While surgery (e.g., **thyroidectomy**) is the primary treatment for localized thyroid cancer and can be used to resect some metastases, it is **not always feasible** for all metastatic sites, especially widely disseminated disease. - Surgery for widespread metastases carries significant risks and may not be curative if all tumor burden cannot be removed. *Thyroxine* - **Thyroxine (T4)** replacement therapy is crucial after thyroidectomy to replace missing hormones and to **suppress TSH** production, which can stimulate residual cancer growth [1]. - However, thyroxine itself does **not directly destroy** existing metastases; it's a supportive and suppressive therapy, not a primary treatment for metastases. *Observation* - **Observation** is generally not appropriate for treating metastases from **follicular carcinoma**, as these metastases have the potential to grow and lead to significant morbidity and mortality if left untreated. - Active treatment is usually indicated to improve prognosis and quality of life.

Q: A 4 cm thyroid nodule that is mobile but causing compressive symptoms presents several considerations. Which of the following statements is false?

Cold nodules are always malignant.. ***Cold nodules are always malignant.*** - This statement is **false** because while **cold nodules** (those that do not take up radioactive iodine on scintigraphy) have a higher risk of malignancy compared to hot nodules, the vast majority are still **benign**. - Approximately **80-85% of cold nodules are benign**, emphasizing that a cold appearance on scan is an indicator for further investigation, not a definitive diagnosis of cancer. *FNAC is the first-line investigation of choice for thyroid nodules.* - This statement is **true** as fine needle aspiration cytology (**FNAC**) is the **first-line investigation** for evaluating thyroid nodules. - It is minimally invasive, cost-effective, and has high sensitivity and specificity for diagnosing thyroid malignancy. *Management may include subtotal thyroidectomy in certain cases.* - This statement is **true** as **subtotal thyroidectomy** can be considered for **benign multinodular goiter** causing compressive symptoms, especially when total thyroidectomy is deemed too aggressive or increases complication risk. - This approach aims to relieve compression while preserving some thyroid function. *FNAC cannot reliably distinguish between follicular adenoma and carcinoma.* - This statement is **true** because the distinction between a **follicular adenoma** (benign) and a **follicular carcinoma** (malignant) relies on identifying **capsular or vascular invasion**, which cannot be assessed by cytology alone. - A **surgical biopsy** like lobectomy is often required for definitive diagnosis of follicular lesions.

Question 1

Which metastases are most common to the thyroid?

Accepted Answer

Kidney

Answer

GIT

Answer

Lung

Answer

Breast

Question 2

Hypoparathyroidism following thyroid surgery occurs within:

Accepted Answer

24 hours

Answer

2 - 5 days

Answer

7-14 days

Answer

2 - 3 weeks

Question 3

Which of the following factors is not included in the MACIS score used for the prognosis of papillary thyroid cancer?

Accepted Answer

Mitotic index

Answer

Age

Answer

Size

Answer

Excision completion in surgery

Question 4

Which of the following is NOT a classification of retrosternal goiter?

Accepted Answer

Nodular goiter.

Answer

Substernal.

Answer

Plunging.

Answer

Intrathoracic.

Question 5

Most common injured nerve after thyroidectomy is?

Accepted Answer

Recurrent laryngeal nerve

Answer

Superior laryngeal nerve

Answer

External laryngeal nerve

Answer

Nerve to omohyoid

Question 6

A patient diagnosed with papillary carcinoma of the thyroid underwent a whole-body iodine scan six weeks after surgery, which revealed residual disease. The next best step is:

Accepted Answer

Radioiodine ablation

Answer

Surgical removal of residual disease

Answer

FNAC of the residual tissue followed by radioiodine ablation

Answer

Neck ultrasound and serum thyroglobulin level measurement

Question 7

A middle-aged patient presents with a woody-hard thyroid gland that is fixed to surrounding structures and does not move with deglutition. The patient is euthyroid and the condition has been slowly progressive. What is the most likely diagnosis?

Accepted Answer

Reidel's thyroiditis.

Answer

Anaplastic thyroid carcinoma.

Answer

Retrosternal goitre.

Answer

None of the options.

Question 8

What is the most appropriate surgical treatment for primary hyperparathyroidism?

Accepted Answer

Removal of the abnormal gland(s) with preservation of normal glands

Answer

Removal of all four glands

Answer

Calcitonin

Answer

Removal of all glands leaving 50 mg of tissue as remnant

Question 9

Metastases from follicular carcinoma should be treated by:

Accepted Answer

Radioiodine

Answer

Surgery

Answer

Thyroxine

Answer

Observation

Question 10

A 4 cm thyroid nodule that is mobile but causing compressive symptoms presents several considerations. Which of the following statements is false?

Accepted Answer

Cold nodules are always malignant.

Answer

Management may include subtotal thyroidectomy in certain cases.

Answer

FNAC cannot reliably distinguish between follicular adenoma and carcinoma.

Answer

FNAC is the first-line investigation of choice for thyroid nodules.

Endocrine Surgery — MCQs

Endocrine Surgery — MCQs

On this page

Practice by Chapter

Want unlimited practice?