Head and Neck Surgery Practice Questions

Q: A dentigerous cyst arises from which of the following structures?

An unerupted permanent tooth. ### Explanation A **dentigerous cyst** (also known as a follicular cyst) is the most common type of non-inflammatory odontogenic cyst. It originates from the **reduced enamel epithelium** that surrounds the crown of an **unerupted permanent tooth**. #### Why Option C is Correct: The cyst develops due to the accumulation of fluid between the reduced enamel epithelium and the crown of the tooth. It is characteristically attached to the **cemento-enamel junction (CEJ)**. While it can involve any unerupted tooth, it most frequently involves the **mandibular third molars**, followed by the maxillary canines. #### Why Other Options are Incorrect: * **Option A (Root of a carious tooth):** This describes a **Radicular Cyst** (Periapical cyst). It is an inflammatory cyst that forms at the apex of a non-vital, decayed tooth. * **Option B (Periosteum of a fractured mandible):** Trauma or fractures do not lead to dentigerous cysts. Post-traumatic bone cysts (Simple bone cysts) are distinct entities and are not odontogenic in origin. * **Option D (Sequestrum of osteomyelitis):** Osteomyelitis involves necrotic bone (sequestrum) and new bone formation (involucrum). While it can cause swelling, it does not result in the formation of a follicular cyst. #### NEET-PG High-Yield Pearls: * **Radiological Appearance:** Presents as a well-defined, unilocular radiolucency symmetrically surrounding the crown of an unerupted tooth (**"Half-moon" appearance**). * **Most Common Site:** Mandibular 3rd molar > Maxillary canine. * **Complications:** If left untreated, it carries a risk of transforming into an **Ameloblastoma** or, rarely, Squamous Cell Carcinoma. * **Treatment:** Surgical enucleation and removal of the associated tooth.

Q: True about branchial cyst?

Filled with straw colored fluid with cholesterol crystals. **Explanation:** Branchial cysts are congenital developmental defects arising from the persistence of the **second branchial cleft** (95% of cases). **Why Option C is correct:** The cyst is lined by stratified squamous epithelium (or sometimes columnar epithelium). The characteristic fluid within the cyst is **straw-colored** and contains **cholesterol crystals**. These crystals are derived from the breakdown of desquamated epithelial cells within the lymphoid-rich wall. On microscopy, these crystals appear as "rhomboid-shaped" plates with notched corners, which is a pathognomonic finding on Fine Needle Aspiration Cytology (FNAC). **Analysis of Incorrect Options:** * **Option A:** Branchial cysts are typically located at the junction of the **upper 1/3 and middle 1/3** of the anterior border of the sternocleidomastoid muscle, not the lower 1/3. * **Option B:** While the wall contains subepithelial lymphoid follicles (which can lead to enlargement during URTI), the wall itself is primarily composed of **epithelium** (squamous or columnar). * **Option D:** Although congenital, they rarely present at birth. They typically manifest in **late childhood or early adulthood** (2nd or 3rd decade) when the cyst enlarges due to infection or accumulation of fluid. **High-Yield Clinical Pearls for NEET-PG:** * **Location:** "The classic site" is the anterior border of the sternocleidomastoid at the level of the **greater cornu of the hyoid bone**. * **Relation to Vessels:** It lies superficial to the bifurcation of the common carotid artery (between internal and external carotids). * **Differential Diagnosis:** Must be differentiated from a **Carotid Body Tumor** (which is pulsatile and has a positive Fontaine’s sign) and **Cystic Hygroma** (which transilluminates). * **Treatment:** Complete surgical excision (Stebbing’s operation) is the treatment of choice.

Q: Which lymph nodes are included in Level V of cervical lymph node classification?

Posterior triangle nodes. ### Explanation The cervical lymph node classification system (Memorial Sloan Kettering Cancer Center) divides the neck into six levels to standardize surgical and oncological communication. **1. Why the Correct Answer is Right:** **Level V** refers to the **Posterior Triangle nodes**. These are anatomically bounded anteriorly by the posterior border of the sternocleidomastoid (SCM) muscle, posteriorly by the anterior border of the trapezius muscle, and inferiorly by the clavicle. This level includes the spinal accessory nodes, transverse cervical nodes, and supraclavicular nodes. **2. Why the Other Options are Wrong:** * **Option A (Upper jugular nodes):** These constitute **Level II**. They extend from the skull base to the level of the hyoid bone (or carotid bifurcation). * **Option B (Middle jugular nodes):** These constitute **Level III**. They extend from the hyoid bone to the lower border of the cricoid cartilage (or omohyoid muscle). * **Option C (Lower jugular nodes):** These constitute **Level IV**. They extend from the cricoid cartilage down to the clavicle. **3. High-Yield Clinical Pearls for NEET-PG:** * **Level I:** Submental (Ia) and Submandibular (Ib) nodes. * **Level VI:** Anterior compartment nodes (pre-laryngeal, pre-tracheal, and para-tracheal). * **Level VII:** Superior mediastinal nodes (below the suprasternal notch). * **Boundary Landmark:** The **Spinal Accessory Nerve (CN XI)** passes through Level V; damage to it during neck dissection leads to "shoulder drop" and inability to shrug. * **Virchow’s Node:** A sentinel lymph node in the left supraclavicular fossa (part of Level V) often associated with gastric malignancy (Troisier’s sign).

Q: A thyroglossal cyst is typically found in which anatomical region?

All of the above. ### Explanation **Underlying Medical Concept:** A thyroglossal cyst is a congenital anomaly resulting from the failure of the **thyroglossal duct** to obliterate. During embryogenesis, the thyroid gland descends from the *foramen caecum* at the base of the tongue to its final position in the neck. This descent follows a midline path that passes anterior to, through, or posterior to the hyoid bone. Consequently, a cyst can develop anywhere along this migratory tract. **Analysis of Options:** The distribution of thyroglossal cysts along the midline is as follows: * **Subhyoid (Beneath the hyoid bone):** This is the **most common** site (approx. 50–60%). * **Thyroid Cartilage region:** Cysts frequently occur at the level of the thyroid cartilage (approx. 20–25%). * **Cricoid level:** Though less common, they can occur as low as the cricoid cartilage or the suprasternal notch. * **Suprahyoid:** About 20% occur above the hyoid bone. Since the cyst can manifest at any of these anatomical levels along the midline, **Option D (All of the above)** is correct. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Presentation:** A midline neck swelling that **moves upwards on protrusion of the tongue** (due to its attachment to the hyoid bone via the tract) and on deglutition (swallowing). * **Most Common Site:** Subhyoid. * **Surgical Management:** The **Sistrunk Operation** is the gold standard. It involves excision of the cyst, the entire tract, and the **central part of the hyoid bone** to minimize recurrence. * **Carcinoma Risk:** Though rare (<1%), the most common malignancy arising in a thyroglossal cyst is **Papillary Thyroid Carcinoma**.

Q: What is the most common site of palpable metastasis in the neck at the time of presentation?

Carcinoma of the tongue. **Explanation:** The correct answer is **Carcinoma of the Tongue**. This is primarily due to the tongue's rich lymphatic drainage and its constant muscular activity, which facilitates the early embolic spread of malignant cells to the regional lymph nodes. **Why Carcinoma of the Tongue is Correct:** Approximately **40–50%** of patients with squamous cell carcinoma (SCC) of the tongue present with palpable cervical lymphadenopathy at the time of diagnosis. The lateral borders and the posterior third (base) of the tongue have an extensive network of lymphatic vessels that drain directly into Level II (upper deep cervical) and Level III (middle deep cervical) nodes. Because the tongue is a highly mobile muscular organ, the "milking action" of swallowing and speaking promotes early metastasis. **Why the other options are incorrect:** * **Buccal Mucosa:** While common in India due to tobacco chewing, it generally has a lower incidence of early nodal metastasis (approx. 10–30%) compared to the tongue. * **Alveolus:** Carcinoma of the alveolus often presents with bone involvement (mandible/maxilla) before extensive lymphatic spread. * **Lip:** Carcinoma of the lip (usually the lower lip) is the least aggressive of the oral cavity cancers. It grows slowly and has a low rate of metastasis (approx. 5–10%) at presentation. **Clinical Pearls for NEET-PG:** * **Most common site of Oral Cancer in India:** Buccal Mucosa (due to *Khaini/Gutka*). * **Most common site of Oral Cancer Worldwide:** Lip (lower lip). * **Most common site of Nodal Metastasis:** Level II (Jugulodigastric node). * **TNM Staging:** The presence of a single ipsilateral node >3cm but ≤6cm is classified as **N2a**. * **Skip Metastasis:** Tongue cancers can sometimes skip Level I and go directly to Level III or IV.

Q: A brilliantly transilluminant tumor in the neck may be:

Cystic hygroma. **Explanation** The correct answer is **Cystic Hygroma**. **1. Why Cystic Hygroma is the correct answer:** A cystic hygroma is a congenital malformation of the lymphatic system (lymphangioma) characterized by large, fluid-filled sacs. Because these cysts contain **clear, straw-colored serous fluid** and have very thin walls, they allow light to pass through easily. This results in **brilliant transillumination**, which is the hallmark clinical sign used to differentiate it from other neck swellings. They are most commonly found in the posterior triangle of the neck. **2. Why the other options are incorrect:** * **Branchial Cyst:** These are usually located at the junction of the upper 1/3rd and lower 2/3rds of the anterior border of the sternomastoid. They contain **mucoid fluid rich in cholesterol crystals**, which makes the fluid turbid/opaque; hence, they are typically **not transilluminant**. * **Thyroglossal Cyst:** Located in the midline (usually infrahyoid), these contain thick, mucoid material. While they move with deglutition and protrusion of the tongue, they are **not transilluminant**. * **Sternomastoid Tumor:** This is actually a fibromatosis (pseudotumor) within the muscle fibers (often causing torticollis). It is a **solid mass**, and solid masses do not transilluminate. **3. Clinical Pearls for NEET-PG:** * **Brilliant Transillumination:** Think Cystic Hygroma, Hydrocele, or Ranula. * **Cystic Hygroma Association:** Frequently associated with chromosomal abnormalities like **Turner Syndrome** and Down Syndrome. * **Treatment of Choice:** Surgical excision is preferred, but **Sclerotherapy** (using OK-432 or Bleomycin) is an alternative for macrocystic lesions. * **Complication:** The most common complication is sudden enlargement due to hemorrhage or infection.

Q: Which of the following statements regarding carotid body tumors is correct?

May metastasize. **Explanation:** **Carotid Body Tumors (CBTs)**, also known as **Chemodectomas** or **Paragangliomas**, are rare, highly vascular neuroendocrine tumors arising from the paraganglion cells (chemoreceptors) located at the bifurcation of the common carotid artery. 1. **Why Option D is Correct:** While most carotid body tumors are benign, approximately **5% to 10% are malignant**. Malignancy cannot be determined by histology alone (as benign and malignant cells look identical); it is defined clinically by the presence of **metastasis** to regional lymph nodes or distant organs (lungs, bones). 2. **Why Incorrect Options are Wrong:** * **Option A & B:** CBTs originate from **Type I (Chief) cells**, which are derived from the **neural crest**. They do not arise from endothelial cells (vascular origin) or Schwann cells (nerve sheath origin). * **Option C:** The treatment of choice is **surgical excision**. Radiation therapy is generally reserved for elderly patients, non-surgical candidates, or unresectable/recurrent tumors to achieve local control, but it is not the primary modality. **High-Yield Clinical Pearls for NEET-PG:** * **Fontaine’s Sign:** The tumor is mobile horizontally but fixed vertically (due to its attachment within the carotid bifurcation). * **Lyre Sign:** On angiography, the tumor causes widening/splaying of the carotid bifurcation (displacement of internal and external carotid arteries). * **Shamblin Classification:** Used to grade the tumor based on its involvement/encasement of the carotid vessels. * **Inheritance:** Most are sporadic, but 10–35% are familial (associated with *SDH* gene mutations). Familial cases are more likely to be bilateral.

Q: Which nerve is affected in Shoulder dysfunction Syndrome, a complication of radical node dissection?

Accessory nerve. **Explanation:** **Shoulder Dysfunction Syndrome** is a classic complication following Radical Neck Dissection (RND) caused by injury or sacrifice of the **Spinal Accessory Nerve (CN XI)**. 1. **Why the Accessory Nerve is correct:** The Spinal Accessory Nerve provides motor innervation to the **Sternocleidomastoid** and **Trapezius** muscles. In a classical RND, this nerve is intentionally sacrificed to ensure oncological clearance of Level II-V lymph nodes. Its loss leads to denervation and atrophy of the trapezius, resulting in the clinical triad of Shoulder Dysfunction Syndrome: **shoulder pain, drooping of the shoulder (scapular winging), and inability to abduct the arm above 90 degrees.** 2. **Why other options are incorrect:** * **Vagus Nerve (CN X):** Injury leads to vocal cord paralysis (hoarseness) and loss of gag reflex, but does not affect shoulder mobility. * **Hypoglossal Nerve (CN XII):** Injury results in ipsilateral tongue deviation and atrophy. * **Phrenic Nerve:** Injury leads to ipsilateral diaphragmatic paralysis (seen as an elevated hemidiaphragm on X-ray), affecting respiration rather than shoulder function. **Clinical Pearls for NEET-PG:** * **Modified Radical Neck Dissection (MRND):** Type I MRND specifically aims to **preserve the Spinal Accessory Nerve** to prevent this syndrome. * **Nerve Identification:** The nerve is found at **Erb’s point** (posterior border of SCM) and enters the trapezius approximately 2-3 cm above the clavicle. * **Rehabilitation:** If the nerve is sacrificed, patients require aggressive physical therapy to strengthen the levator scapulae and rhomboid muscles to compensate for the lost trapezius function.

Question 1

A dentigerous cyst arises from which of the following structures?

Accepted Answer

An unerupted permanent tooth

Answer

The root of a carious tooth

Answer

The periosteum of a fractured mandible

Answer

The sequestrum of osteomyelitis of the mandible

Question 2

True about branchial cyst?

Accepted Answer

Filled with straw colored fluid with cholesterol crystals

Answer

Seen deep to lower 1/3 of sternocleidomastoid

Answer

Wall consists of lymphoid tissue

Answer

Presents at birth

Question 3

Which lymph nodes are included in Level V of cervical lymph node classification?

Accepted Answer

Posterior triangle nodes

Answer

Upper jugular nodes

Answer

Middle jugular nodes

Answer

Lower jugular nodes

Question 4

When a down fracture Le Fort I osteotomy is performed, which of the following is true?

Accepted Answer

A patient with a cleft palate is more likely to develop necrosis.

Answer

Necrosis is prevented by a blood supply to the maxilla from the palatine arteries.

Answer

The operation is easier on a cleft palate patient because the lesser segment does not have to be detached from the nose.

Answer

A tear in the nasal mucosa makes postoperative infection more likely.

Question 5

Blow out carotid is characteristically seen with:

Accepted Answer

Radical neck dissection

Answer

Thyroidectomy

Answer

Flap necrosis

Answer

Sistrunk operation

Question 6

A thyroglossal cyst is typically found in which anatomical region?

Accepted Answer

All of the above

Answer

Beneath the hyoid bone

Answer

In the region of the thyroid cartilage

Answer

Opposite the cricoid cartilage

Question 7

What is the most common site of palpable metastasis in the neck at the time of presentation?

Accepted Answer

Carcinoma of the tongue

Answer

Buccal mucosa

Answer

Alveolus

Answer

Lip

Question 8

A brilliantly transilluminant tumor in the neck may be:

Accepted Answer

Cystic hygroma

Answer

Branchial cyst

Answer

Thyroglossal cyst

Answer

Sternomastoid tumor

Question 9

Which of the following statements regarding carotid body tumors is correct?

Accepted Answer

May metastasize

Answer

Arises from the endothelial cells

Answer

Originates from the Schwann cells

Answer

Radiation therapy is the treatment of choice

Question 10

Which nerve is affected in Shoulder dysfunction Syndrome, a complication of radical node dissection?

Accepted Answer

Accessory nerve

Answer

Vagus nerve

Answer

Hypoglossal Nerve

Answer

Phrenic Nerve

Head and Neck Surgery — MCQs

Head and Neck Surgery — MCQs

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