Endocrine Surgery Practice Questions

Q: Which nerve is most likely injured during a thyroidectomy?

Recurrent laryngeal. ***Recurrent laryngeal*** - The **recurrent laryngeal nerves** are highly susceptible to injury during thyroidectomy due to their close anatomical proximity to the **thyroid gland** and their relatively superficial course within the operative field. - Injury to these nerves can lead to **vocal cord paralysis**, resulting in **hoarseness** or, in cases of bilateral injury, severe airway compromise. *Hypoglossal* - The **hypoglossal nerve** (CN XII) innervates the muscles of the tongue and is located more superiorly and medially, well outside the typical dissection planes for a thyroidectomy. - Damage to this nerve would primarily affect **tongue movement** and speech articulation, symptoms not commonly associated with thyroid surgery complications. *Phrenic nerve* - The **phrenic nerve** innervates the diaphragm and is situated deep in the neck and thorax, far from the thyroid surgical field. - Injury during thyroidectomy is extremely rare and would lead to **diaphragmatic paralysis**, causing respiratory difficulties. *Superior laryngeal* - The **superior laryngeal nerve** descends alongside the superior thyroid artery and typically divides into internal and external branches; the **external branch** is at risk during ligation of the superior thyroid pedicle. - While it can be injured, the **recurrent laryngeal nerve** is more frequently and severely affected, particularly its motor function to the intrinsic laryngeal muscles, which is most critical for voice production.

Q: In a patient undergoing thyroid surgery, which complication is associated with injury to the recurrent laryngeal nerve?

Stridor. ***Stridor*** - Injury to the recurrent laryngeal nerve can lead to **vocal cord paralysis**, causing narrowing of the airway and producing a high-pitched, harsh sound known as **stridor**. - **Bilateral recurrent laryngeal nerve injury** is particularly dangerous as it can cause complete airway obstruction due to paralysis of both vocal cords in the adducted position. - Stridor is the **most characteristic and serious** complication of RLN injury requiring immediate management. *Dysphagia* - While **RLN injury can cause some swallowing difficulties** due to impaired glottic closure and aspiration risk, dysphagia is **not the most specific complication** of RLN injury. - **Superior laryngeal nerve injury** causes more prominent dysphagia by affecting the cricothyroid muscle and sensory innervation of the larynx. - Compared to stridor, dysphagia is a less specific finding for RLN injury and not the primary concern. *Hypocalcemia* - **Hypocalcemia** is a common complication of thyroid surgery caused by accidental removal or damage to the **parathyroid glands**, which are located near the thyroid. - The **parathyroid glands** regulate calcium levels in the blood, and their dysfunction leads to decreased parathyroid hormone production. - This is unrelated to nerve injury. *Hypertension* - **Hypertension** is not a direct or recognized complication of recurrent laryngeal nerve injury during thyroid surgery. - It might occur as a transient response to surgical stress or pain, but it is not linked to RLN damage.

Q: During thyroidectomy, which nerve, if damaged, can cause a hoarse voice?

Recurrent laryngeal; loops under aorta/subclavian. ***Recurrent laryngeal; loops under aorta/subclavian*** - The **recurrent laryngeal nerve (RLN)** innervates most of the intrinsic muscles of the larynx, including the **posterior crico-arytenoid muscle**, which is responsible for abducting the vocal cords. - Damage to the RLN during thyroidectomy can lead to **vocal cord paralysis**, resulting in a hoarse voice, stridor, or aspiration. *Superior laryngeal; with superior thyroid artery* - The **superior laryngeal nerve (SLN)** branches into external and internal laryngeal nerves. The **external laryngeal nerve** runs with the **superior thyroid artery** and innervates the **cricothyroid muscle**, which is responsible for tensioning the vocal cords. - Damage to the SLN can cause subtle changes in voice pitch and reduced vocal range but typically does not cause hoarseness or vocal cord paralysis, which is more characteristic of RLN injury. *Glossopharyngeal; along posterior thyroid* - The **glossopharyngeal nerve (CN IX)** provides sensory innervation to the posterior third of the tongue, tonsils, pharynx, and middle ear, and motor innervation to the stylopharyngeus muscle. - It is not directly related to vocal cord function or hoarseness as a result of thyroid surgery. *Hypoglossal; inferior to thyroid* - The **hypoglossal nerve (CN XII)** innervates all extrinsic and intrinsic muscles of the tongue, controlling tongue movement. - Damage to the hypoglossal nerve would affect speech articulation and swallowing but not directly cause hoarseness or vocal cord paralysis.

Q: A 30-year-old woman presents with hypercalcemia and kidney stones. Imaging reveals a thyroid mass, and histology shows spindle cells and amyloid deposits within the tumor. How would you manage this condition?

Total thyroidectomy. ***Total thyroidectomy*** - Given the presence of a thyroid mass with **hypercalcemia** and **distinct histological findings**, a total thyroidectomy is indicated to remove the tumor completely [1]. - This approach addresses the potential for malignancy and prevents further complications such as hypercalcemia and kidney stones. *Observation with serial ultrasound* - Not appropriate due to the **presence of hypercalcemia** and the **thyroid mass**, which raises concern for malignancy. - Delaying intervention could lead to worsening symptoms and complications. *Radiation therapy to the thyroid* - Typically utilized for **postoperative management** or in the presence of **differentiated thyroid carcinoma**, not as a primary treatment for a suspicious thyroid mass. - It does not address the mass directly and may not alleviate the immediate symptoms of hypercalcemia. *Chemotherapy with targeted therapy* - Not indicated for thyroid tumors unless it is clearly a **dedifferentiated or advanced carcinoma**. - There is insufficient evidence to suggest chemotherapy is effective for the management of thyroid masses with associated hypercalcemia. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1102-1103.

Q: A patient presents with difficulty swallowing (dysphagia) and hoarseness of voice following a thyroidectomy. Damage to which nerve is most likely responsible for these symptoms?

Recurrent laryngeal nerve (RLN). ***Recurrent laryngeal nerve (RLN)*** - The **RLN** innervates most intrinsic laryngeal muscles, which are crucial for **vocalization** and **swallowing coordination**. - Injury to the RLN during thyroidectomy is a common complication, leading to **hoarseness of voice** (due to vocal cord paresis/paralysis) and **dysphagia** (due to impaired glottic closure during swallowing). *Hypoglossal nerve* - The **hypoglossal nerve (CN XII)** primarily controls the **tongue muscles**, affecting speech articulation and food manipulation within the mouth. - Damage would typically cause **tongue deviation** and difficulty with speech, rather than primary hoarseness or dysphagia related to vocal cord function. *Vagus nerve* - While the **vagus nerve (CN X)** is the parent nerve of the RLN, direct damage to the main vagus trunk (e.g., above the origin of the RLN) would cause more widespread dysfunction. - This would include a broader range of autonomic and motor deficits, such as difficulties with taste, gag reflex, and potentially more severe swallowing problems, but not specifically isolated hoarseness and dysphagia as seen here. *Glossopharyngeal nerve* - The **glossopharyngeal nerve (CN IX)** is involved in the **gag reflex**, taste from the posterior tongue, and sensation from the pharynx. - Damage typically results in loss of gag reflex, impaired taste, and difficulty initiating swallowing (impairment of the pharyngeal phase), but less directly in hoarseness related to vocal cord function.

Q: A 40-year-old woman with a thyroid nodule undergoes a fine-needle aspiration biopsy that reveals orphan Annie eye nuclei. What is the most appropriate next step in management?

Lobectomy with histopathology. ***Lobectomy with histopathology*** - A lobectomy provides a definitive diagnosis through **histopathological examination**, which can distinguish between benign and malignant thyroid lesions [1,2]. - This surgical approach allows for accurate assessment of the **tumor's architecture** and cellular characteristics, confirming the presence of malignancy if present [2,3]. *Radioactive iodine uptake scan* - Primarily used to assess **thyroid function** rather than determine malignancy in thyroid nodules. - It helps differentiate between **hyperfunctioning** and **hypofunctioning** nodules but does not provide tissue diagnosis. *Core needle biopsy* - While a core needle biopsy provides larger tissue samples than FNA, it is still less definitive than lobectomy for assessing **malignancy**. - In some cases, it might miss important features that require surgical review. *Repeat FNA with molecular analysis* - Although can give additional insights, it may not provide a definitive diagnosis since FNA results can still be ambiguous. - The presence of **Orphan Annie eye nuclei** suggests possible malignancy, necessitating a more conclusive **surgical intervention** [1,2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 429-430. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, p. 1099. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1099-1100.

Question 1

Which nerve is most likely injured during a thyroidectomy?

Accepted Answer

Recurrent laryngeal

Answer

Hypoglossal

Answer

Phrenic nerve

Answer

Superior laryngeal

Question 2

For a patient with multiple endocrine neoplasia type 1 (MEN1) and primary hyperparathyroidism, how do you determine the extent of parathyroid surgery?

Accepted Answer

All patients undergo total parathyroidectomy with autotransplantation

Answer

Surgery is not indicated in genetic cases

Answer

Decision based solely on serum calcium levels

Answer

The extent of surgery is determined by the number of glands involved and specific genetic study results.

Question 3

In a patient undergoing thyroid surgery, which complication is associated with injury to the recurrent laryngeal nerve?

Accepted Answer

Stridor

Answer

Dysphagia

Answer

Hypocalcemia

Answer

Hypertension

Question 4

During thyroidectomy, which nerve, if damaged, can cause a hoarse voice?

Accepted Answer

Recurrent laryngeal; loops under aorta/subclavian

Answer

Superior laryngeal; with superior thyroid artery

Answer

Glossopharyngeal; along posterior thyroid

Answer

Hypoglossal; inferior to thyroid

Question 5

A 30-year-old woman presents with hypercalcemia and kidney stones. Imaging reveals a thyroid mass, and histology shows spindle cells and amyloid deposits within the tumor. How would you manage this condition?

Accepted Answer

Total thyroidectomy

Answer

Chemotherapy with targeted therapy

Answer

Radiation therapy to the thyroid

Answer

Observation with serial ultrasound

Question 6

A 25-year-old woman has a 4 cm thyroid nodule that is suspicious for cancer. What is the best next step in management?

Accepted Answer

Lobectomy

Answer

Radioactive iodine

Answer

Observation

Answer

Total thyroidectomy

Question 7

A patient presents with difficulty swallowing (dysphagia) and hoarseness of voice following a thyroidectomy. Damage to which nerve is most likely responsible for these symptoms?

Accepted Answer

Recurrent laryngeal nerve (RLN)

Answer

Hypoglossal nerve

Answer

Vagus nerve

Answer

Glossopharyngeal nerve

Question 8

For a patient undergoing thyroidectomy for papillary thyroid cancer, how should the extent of lymph node dissection be determined?

Accepted Answer

Based on preoperative ultrasound and intraoperative findings

Answer

Remove all cervical lymph nodes without consideration of findings

Answer

Only perform lymph node dissection if nodes are clinically palpable and visible on imaging

Answer

Decision based on postoperative pathology of the primary tumor

Question 9

A 40-year-old woman with a thyroid nodule undergoes a fine-needle aspiration biopsy that reveals orphan Annie eye nuclei. What is the most appropriate next step in management?

Accepted Answer

Lobectomy with histopathology

Answer

Core needle biopsy

Answer

Repeat FNA with molecular analysis

Answer

Radioactive iodine uptake scan

Question 10

A patient undergoes a thyroidectomy and presents postoperatively with tingling in the hands and around the mouth. What is the likely cause?

Accepted Answer

Hypocalcemia due to accidental removal of parathyroid glands

Answer

Thyroid storm

Answer

Hypoglycemia

Answer

Surgical site infection

Endocrine Surgery — MCQs

Endocrine Surgery — MCQs

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