Head and Neck Surgery Practice Questions

Q: A 4-year-old boy is brought to the physician's office for evaluation of small stature. A thyroid scan shows no uptake in the neck. Which structure is embryologically related to the thyroid gland and should be carefully evaluated?

Foramen cecum. ### Explanation **1. Why Foramen Cecum is Correct:** The thyroid gland begins its development as an endodermal proliferation at the floor of the pharynx, specifically at a point between the tuberculum impar and the copula. This site of origin is marked in the adult tongue by the **foramen cecum**. During the 4th week of gestation, the thyroid primordium descends from the foramen cecum to its final position in the neck via the **thyroglossal duct**. In this clinical scenario, the lack of uptake in the neck suggests **thyroid dysgenesis** (likely an ectopic thyroid). The most common site for an ectopic thyroid is the lingual region, located at the base of the tongue near the foramen cecum. **2. Why Other Options are Incorrect:** * **B, C, and D (Foramen Ovale, Rotundum, and Spinosum):** These are openings in the **greater wing of the sphenoid bone** at the base of the skull. They transmit cranial nerves (V2, V3) and vessels (middle meningeal artery). They are derived from the neurocranium and have no embryological or anatomical relationship with the descent of the thyroid gland or the pharyngeal arches. **3. NEET-PG High-Yield Pearls:** * **Ectopic Thyroid:** The most common location is the **Lingual Thyroid** (at the foramen cecum). If a lingual thyroid is present, it is often the *only* functioning thyroid tissue in 70% of cases; surgical removal without replacement leads to permanent hypothyroidism. * **Thyroglossal Duct Cyst:** Occurs due to failure of the duct to obliterate. It is typically a midline neck swelling that **moves upward on protrusion of the tongue** (due to its attachment to the hyoid bone and foramen cecum). * **Pyramidal Lobe:** A normal anatomical variant representing a persistent distal portion of the thyroglossal duct.

Q: In the classical radical neck dissection (Crile), which structure is NOT removed?

None of the above. ### Explanation The **Classical Radical Neck Dissection (RND)**, originally described by George Crile in 1906, is the gold standard surgical procedure for managing cervical lymph node metastasis. The fundamental principle of RND is the en-bloc removal of all lymphatic tissues from one side of the neck. **Why "None of the above" is correct:** In a Classical RND, three specific non-lymphatic structures are routinely sacrificed to ensure complete oncological clearance of the associated lymph nodes. These are: 1. **Sternocleidomastoid muscle (SCM)** 2. **Internal Jugular Vein (IJV)** 3. **Spinal Accessory Nerve (SAN - Cranial Nerve XI)** Since options A, B, and C (Cervical lymph nodes, SCM, and IJV) are all standard components removed during the procedure, none of them are "not removed." **Analysis of Options:** * **Cervical group of lymph nodes:** RND removes lymph node levels I through V. This is the primary goal of the surgery. * **Sternocleidomastoid muscle:** Removed to gain access to the deep cervical nodes and ensure clearance of the lymphatic channels piercing the muscle. * **Internal jugular vein:** Removed because the deep cervical lymph nodes are intimately attached to its adventitia. **High-Yield Clinical Pearls for NEET-PG:** * **Modified Radical Neck Dissection (MRND):** This involves the removal of lymph node levels I-V but **preserves** one or more non-lymphatic structures (SAN, IJV, or SCM). * *Type I:* Preserves Spinal Accessory Nerve. * *Type II:* Preserves SAN and IJV. * *Type III (Functional Neck Dissection):* Preserves all three (SAN, IJV, and SCM). * **Extended Neck Dissection:** Removal of additional lymph node groups (e.g., Level VI) or non-lymphatic structures (e.g., Carotid artery, Hypoglossal nerve) not included in the classical RND. * **Most common complication of RND:** Shoulder dysfunction/droop (due to sacrifice of the Spinal Accessory Nerve).

Q: A 40-year-old woman presents with a painless mass anterior to her left ear. The mass had been slowly enlarging over the past year. The mass is firm and nontender. Computed tomography and magnetic resonance imaging reveal a well-circumscribed, homogeneous mass within the left parotid gland. Biopsy reveals anastomosing strands of stellate and fusiform epithelial cells embedded in a myxoid stroma. Which of the following is a characteristic of this lesion?

Recurrence often takes place after surgical resection.. **Explanation:** The clinical presentation and histopathology describe a **Pleomorphic Adenoma** (Benign Mixed Tumor), the most common salivary gland tumor. The biopsy findings of epithelial cells (stellate/fusiform) in a myxoid or chondroid stroma are pathognomonic. **Why Option D is Correct:** Pleomorphic adenomas are notorious for **recurrence** if not managed properly. This occurs due to two main reasons: 1. **Pseudopodia:** Microscopic finger-like projections of the tumor extend beyond the main capsule. 2. **Enucleation risks:** Simple enucleation often leaves behind these projections or leads to "seeding" if the capsule ruptures. To prevent recurrence, the standard treatment is **Superficial Parotidectomy** (sparing the facial nerve). **Why Other Options are Incorrect:** * **Option A:** Papillary cystadenoma lymphomatosum is the synonym for **Warthin’s Tumor**, which is characterized by cystic spaces and a dense lymphoid stroma with germinal centers. * **Option B:** Pleomorphic adenoma is most commonly found in the **Parotid gland** (80%), not the submandibular gland. * **Option C:** It is the most common **benign** tumor. The most common malignant salivary gland tumor is **Mucoepidermoid carcinoma**. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** Superficial lobe of the Parotid gland. * **Risk of Malignancy:** Approximately 3–5% can undergo malignant transformation into **Carcinoma ex pleomorphic adenoma** (suspect if a long-standing mass suddenly grows rapidly or causes facial nerve palsy). * **Hot Spot:** On Tc-99m pertechnetate scan, Warthin’s tumor and Oncocytoma show increased uptake, while Pleomorphic Adenoma appears as a "cold" lesion.

Q: In Submandibular gland surgery, which nerve is least likely to be injured?

Inferior alveolar nerve. **Explanation:** The submandibular gland is located in the submandibular triangle, and its surgical removal (excision) requires careful dissection to avoid damaging several closely related nerves. **Why Inferior Alveolar Nerve is the Correct Answer:** The **Inferior Alveolar Nerve** is a branch of the mandibular nerve (V3) that enters the mandibular foramen to supply the lower teeth and chin. It runs deep within the bony canal of the mandible. Since it is protected by bone and is superior to the surgical field of the submandibular gland, it is **least likely** to be injured during routine gland excision. **Analysis of Incorrect Options:** * **Mandibular branch of facial nerve (Marginal Mandibular Nerve):** This is the nerve **most commonly injured** during the initial skin incision. It runs superficial to the submandibular gland fascia. To protect it, the incision is made 2 cm below the lower border of the mandible (Hayes Martin maneuver). * **Lingual Nerve:** This nerve lies deep to the gland and is connected to the submandibular ganglion. It is at risk during the ligation of the submandibular duct (Wharton’s duct), as the nerve "loops" under the duct. * **Hypoglossal Nerve:** This nerve forms the floor of the submandibular triangle (within the Lesser’s triangle). It lies deep to the tendon of the digastric muscle and the submandibular gland; it can be injured during deep dissection. **NEET-PG High-Yield Pearls:** 1. **Most common nerve injured:** Marginal Mandibular Nerve (leads to drooping of the corner of the mouth). 2. **Nerve related to the duct:** The Lingual nerve "double crosses" the submandibular duct. 3. **Incision safety:** Always make the incision 2 cm below the mandible to avoid the marginal mandibular nerve. 4. **Secretomotor pathway:** Parasympathetic fibers to the gland travel via the Chorda Tympani (branch of Facial nerve) and the Lingual nerve.

Q: Carcinoma of the tongue most commonly occurs at which location?

Lateral border of the anterior two-thirds. **Explanation:** **Carcinoma of the tongue** is the most common intraoral cancer. The **lateral border of the anterior two-thirds** (oral tongue) is the most frequent site, accounting for approximately 75% of cases. This area is highly susceptible because it is a "dependent" area where carcinogens in saliva (from tobacco and alcohol) pool and remain in prolonged contact with the mucosa. Additionally, chronic mechanical irritation from jagged teeth or ill-fitting dentures often occurs along the lateral margins. **Analysis of Options:** * **Dorsum (Option A):** This is the least common site for malignancy. The thick keratinized epithelium and dense filiform papillae provide a protective barrier against chemical and mechanical trauma. * **Lateral border of the posterior one-third (Option C):** This refers to the base of the tongue (oropharynx). While tumors here are often more aggressive and diagnosed at a later stage due to rich lymphatic drainage, they are statistically less common than those on the anterior lateral borders. * **Tip (Option D):** While possible, the tip is a rare primary site compared to the lateral edges. **Clinical Pearls for NEET-PG:** * **Histology:** Squamous Cell Carcinoma (SCC) is the most common histological type (>90%). * **Lymphatic Spread:** Tongue cancer has a high propensity for early nodal metastasis. The tip drains to **Submental nodes (Level I)**, the lateral borders to **Submandibular nodes (Level I/II)**, and the posterior third directly to **Deep Cervical nodes (Level II/III)**. * **Premalignant Lesions:** Erythroplakia has a much higher transformation rate to malignancy than Leukoplakia. * **Prognosis:** The most important prognostic factor is the presence of cervical lymph node metastasis.

Q: Which muscle is resected in a classical neck dissection?

Sternocleidomastoid. In Radical Neck Dissection (RND), also known as **Classical Neck Dissection**, the goal is to remove all lymphatic tissue from Levels I to V on one side of the neck. To ensure complete oncological clearance, three specific non-lymphatic structures are routinely sacrificed. ### 1. Why Sternocleidomastoid (SCM) is Correct The **Sternocleidomastoid muscle** is the primary muscle resected in a classical neck dissection. It is removed to provide adequate exposure and access to the deep cervical lymph nodes (Levels II, III, and IV) that lie beneath and adjacent to it. Along with the SCM, the other two "classical" structures resected are: * **Internal Jugular Vein (IJV)** * **Spinal Accessory Nerve (SAN)** ### 2. Why Other Options are Incorrect * **A & B (Sternohyoid & Sternothyroid):** These are "strap muscles" of the neck. While they may be retracted or occasionally divided in thyroid surgeries or laryngectomies, they are not standard components of a classical neck dissection. * **D (Sternocricoid):** This is not a standard anatomical muscle of the neck; it is likely a distractor. ### 3. NEET-PG High-Yield Pearls * **Modified Radical Neck Dissection (MRND):** This is the most common variant today. It involves the same lymph node clearance as RND but **preserves** one or more of the three non-lymphatic structures (SCM, IJV, or SAN). * *Type I:* Preserves SAN. * *Type II:* Preserves SAN and IJV. * *Type III (Functional Neck Dissection):* Preserves all three (SAN, IJV, and SCM). * **Boundary:** The posterior limit of a classical neck dissection is the anterior border of the **Trapezius muscle**. * **Complication:** Resection of the Spinal Accessory Nerve leads to "Shoulder Syndrome" (shoulder pain and inability to abduct the arm above 90 degrees).

Question 1

A 4-year-old boy is brought to the physician's office for evaluation of small stature. A thyroid scan shows no uptake in the neck. Which structure is embryologically related to the thyroid gland and should be carefully evaluated?

Accepted Answer

Foramen cecum

Answer

Foramen ovale

Answer

Foramen rotundum

Answer

Foramen spinosum

Question 2

In the classical radical neck dissection (Crile), which structure is NOT removed?

Accepted Answer

None of the above

Answer

Cervical group of lymph nodes

Answer

Sternocleidomastoid muscle

Answer

Internal jugular vein

Question 3

Which of the following statements is true regarding salivary glands?

Accepted Answer

90% of all parotid tumors are malignant.

Answer

There are more than 400 minor salivary glands.

Answer

90% of minor salivary tumors are malignant.

Answer

Superficial parotidectomy is performed for parotid tumors.

Question 4

A 40-year-old woman presents with a painless mass anterior to her left ear. The mass had been slowly enlarging over the past year. The mass is firm and nontender. Computed tomography and magnetic resonance imaging reveal a well-circumscribed, homogeneous mass within the left parotid gland. Biopsy reveals anastomosing strands of stellate and fusiform epithelial cells embedded in a myxoid stroma. Which of the following is a characteristic of this lesion?

Accepted Answer

Recurrence often takes place after surgical resection.

Answer

It is also called papillary cystadenoma lymphomatosum.

Answer

It is most often localized to the submandibular gland.

Answer

It is the most common malignant salivary gland tumor.

Question 5

A 62-year-old man undergoes excision of a cylindroma of the submandibular gland. He is most likely to have an injury to which of the following nerves?

Accepted Answer

Lingual nerve

Answer

Maxillary branch of the trigeminal nerve

Answer

Vagus nerve

Answer

Hypoglossal nerve

Question 6

Carcinoma of the lip is characterized by the following, except:

Accepted Answer

Lymph node metastases are common, making a radical neck dissection mandatory.

Answer

90% of lip cancers occur on the lower lip.

Answer

The most common site of origin is the vermillion border.

Answer

2 cm x 2 cm cell carcinomas can be treated by V-shaped excision and primary closure.

Question 7

In Submandibular gland surgery, which nerve is least likely to be injured?

Accepted Answer

Inferior alveolar nerve

Answer

Hypoglossal nerve

Answer

Lingual nerve

Answer

Mandibular branch of facial nerve

Question 8

Carcinoma of the tongue most commonly occurs at which location?

Accepted Answer

Lateral border of the anterior two-thirds

Answer

Dorsum

Answer

Lateral border of the posterior one-third

Answer

Tip

Question 9

Which muscle is resected in a classical neck dissection?

Accepted Answer

Sternocleidomastoid

Answer

Sternohyoid

Answer

Sternothyroid

Answer

Sternocricoid

Question 10

Which of the following statements regarding symptomatic thyroglossal duct cysts is true?

Accepted Answer

Treatment includes resection of the hyoid bone

Answer

Over 90% manifest themselves before age 12

Answer

They usually present as a painful swelling in the lateral neck

Answer

Approximately 10-15% contain malignant elements

Head and Neck Surgery — MCQs

Head and Neck Surgery — MCQs

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