Diseases of the Larynx — MCQs

Diseases of the Larynx Indian Medical PG Practice Questions and MCQs

Question 181: What is the most common cause of chronic laryngeal stenosis?

A. Trauma (Correct Answer)
B. Tuberculosis
C. Wegener's granulomatosis
D. Tumor

Explanation: **Explanation:** **Trauma** is the most common cause of chronic laryngeal stenosis. In modern clinical practice, the most frequent subtype is **iatrogenic trauma**, specifically prolonged endotracheal intubation. High-pressure cuffs or oversized tubes cause ischemic necrosis of the laryngeal mucosa, leading to fibrosis and cicatricial narrowing. External laryngeal trauma (e.g., "clothesline" injuries or RTA) is the second most common traumatic cause. **Analysis of Options:** * **Tuberculosis (B):** While TB can cause laryngeal scarring (traditionally affecting the posterior commissure), it is a much rarer cause of stenosis today compared to intubation-related injury. * **Wegener’s Granulomatosis (C):** Now known as Granulomatosis with Polyangiitis (GPA), it typically causes **subglottic stenosis**. While a classic board-exam association, it is statistically rare compared to trauma. * **Tumor (D):** Laryngeal malignancies (like Squamous Cell Carcinoma) cause airway obstruction primarily through mass effect or vocal cord fixation rather than "stenosis" (which refers to a circumferential or cicatricial narrowing of the lumen). **High-Yield Pearls for NEET-PG:** 1. **Most common site of post-intubation stenosis:** Subglottis (the narrowest part of the adult airway and the only complete cartilaginous ring—the cricoid). 2. **Cotton-Myer Classification:** Used to grade the severity of subglottic stenosis based on the percentage of luminal narrowing. 3. **Management:** Grade I/II often respond to endoscopic dilation or laser excision; Grade III/IV usually require surgical reconstruction (e.g., Laryngotracheal Reconstruction or Cricotracheal Resection). 4. **Congenital Stenosis:** If the question specifies *congenital* causes, the most common is a malformed cricoid cartilage.

Question 182: Which is the only laryngeal muscle that is innervated bidirectionally?

A. Vocalis
B. Posterior cricoarytenoid
C. Lateral cricoarytenoid
D. Interarytenoid (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. Interarytenoid** **Concept:** The **Interarytenoid (transverse and oblique arytenoids)** is unique among laryngeal muscles because it is the only one to receive **bilateral (bidirectional) innervation**. It is supplied by the **Recurrent Laryngeal Nerve (RLN)** from both the right and left sides. This anatomical redundancy ensures that even if one RLN is damaged, the muscle can still function to some extent to adduct the posterior part of the vocal cords, helping to close the posterior glottis. **Analysis of Incorrect Options:** * **A. Vocalis:** This is the medial part of the thyroarytenoid muscle. It is supplied solely by the **ipsilateral RLN**. * **B. Posterior cricoarytenoid (PCA):** Known as the "safety muscle of the larynx" (the only abductor), it is supplied only by the **ipsilateral RLN**. * **C. Lateral cricoarytenoid (LCA):** An adductor of the vocal cords, it is supplied only by the **ipsilateral RLN**. **High-Yield Clinical Pearls for NEET-PG:** * **All intrinsic muscles** of the larynx are supplied by the **Recurrent Laryngeal Nerve**, **EXCEPT** the **Cricothyroid**, which is supplied by the **External Laryngeal Nerve** (a branch of the Superior Laryngeal Nerve). * **The "Safety Muscle":** Posterior cricoarytenoid (PCA) is the only muscle that opens (abducts) the vocal cords. * **Semon’s Law:** In progressive lesions of the RLN, the abductors (PCA) are paralyzed before the adductors. * **Position of Cords:** In bilateral RLN palsy, the cords assume a **median or paramedian position**, leading to severe stridor but a relatively preserved voice.

Question 183: Laryngeal papilloma is typically:

A. Single
B. Multiple
C. Seen in children
D. All of the above (Correct Answer)

Explanation: **Explanation:** Laryngeal Papilloma (Recurrent Respiratory Papillomatosis - RRP) is the most common benign neoplasm of the larynx, caused by **Human Papillomavirus (HPV) types 6 and 11**. The disease presents in two distinct clinical forms: 1. **Juvenile Onset (Multiple):** This is the most common form, typically seen in children (usually under age 5). It is characterized by **multiple**, wart-like friable growths that frequently recur after surgical removal. The mode of transmission is often vertical (from mother to child during birth via an infected birth canal). 2. **Adult Onset (Single):** This form usually presents as a **single**, isolated pedunculated lesion in adults (20–40 years). While less aggressive than the juvenile form, it still carries a risk of recurrence. **Why "All of the above" is correct:** The question asks what laryngeal papilloma is *typically*. Since the disease encompasses both the adult form (typically single) and the juvenile form (typically multiple and seen in children), all three descriptors are clinically accurate characteristics of the disease spectrum. **High-Yield Clinical Pearls for NEET-PG:** * **Site:** Most commonly involves the **true vocal cords**. * **Symptom:** Hoarseness of voice is the earliest symptom; stridor may occur in children. * **Treatment of Choice:** CO2 Laser excision or Microdebrider-assisted removal. * **Adjuvant Therapy:** Cidofovir (antiviral) or Interferon-alpha. * **Malignant Transformation:** Rare, but more common in smokers or those with HPV-16/18. * **Histology:** Finger-like projections of non-keratinized stratified squamous epithelium with a central vascular core.

Question 184: Which of the following muscles is an opener of the glottis?

A. Lateral cricoarytenoid
B. Posterior cricoarytenoid (Correct Answer)
C. Transverse arytenoid
D. Interarytenoid

Explanation: **Explanation:** The intrinsic muscles of the larynx are categorized based on their action on the vocal cords (glottis). The **Posterior Cricoarytenoid (PCA)** is the **only abductor** of the vocal cords. It originates from the posterior surface of the cricoid lamina and inserts into the muscular process of the arytenoid cartilage. When it contracts, it rotates the arytenoid cartilages laterally, pulling the vocal processes apart and opening the glottis. This action is vital for respiration. **Analysis of Incorrect Options:** * **A. Lateral cricoarytenoid:** This is the primary **adductor** of the vocal cords. It rotates the arytenoids medially to close the glottis (specifically the ligamentous part). * **C & D. Transverse and Interarytenoids:** These muscles act to adduct the posterior portion of the vocal cords by pulling the two arytenoid cartilages together, thereby closing the posterior commissure (cartilaginous glottis). **Clinical Pearls for NEET-PG:** * **"Safety Muscle of the Larynx":** The Posterior Cricoarytenoid is known as the safety muscle because its paralysis leads to the inability to abduct the cords, potentially causing airway obstruction. * **Nerve Supply:** All intrinsic muscles of the larynx are supplied by the **Recurrent Laryngeal Nerve (RLN)**, *except* for the Cricothyroid, which is supplied by the External Laryngeal Nerve. * **Semon’s Law:** In progressive RLN injury, the abductor fibers (PCA) are more susceptible and are paralyzed before the adductor fibers. * **Cricothyroid Action:** It is the only muscle that **tenses/elongates** the vocal cords (the "singer’s muscle").

Question 185: A middle-aged male presents with a 2-year history of hoarseness of voice. He has a 30-year smoking history. Examination reveals a reddish area of mucosal irregularity overlying a portion of both vocal cords. Which of the following management options would NOT be indicated?

A. Cessation of smoking
B. Bilateral cordectomy (Correct Answer)
C. Microlaryngeal surgery for biopsy
D. Regular follow-up

Explanation: **Explanation:** The clinical presentation of chronic hoarseness in a long-term smoker with "reddish mucosal irregularity" (erythroplakia/leukoplakia) strongly suggests **Chronic Hypertrophic Laryngitis** or **Vocal Cord Dysplasia**, which are premalignant conditions. **Why Bilateral Cordectomy is NOT indicated:** A cordectomy (excision of the vocal cord) is a radical surgical procedure used for localized invasive carcinoma (T1a glottic cancer). Performing a **bilateral** cordectomy for a suspected premalignant lesion is contraindicated because: 1. It is overly aggressive for a condition that has not yet been histologically confirmed as invasive cancer. 2. It results in a devastating loss of voice and a high risk of laryngeal stenosis/airway compromise. **Analysis of other options:** * **Cessation of smoking:** This is the most critical first step in management to prevent further epithelial irritation and progression to malignancy. * **Microlaryngeal surgery (MLS) for biopsy:** This is the **gold standard** for diagnosis. Any suspicious mucosal irregularity must be biopsied to rule out Squamous Cell Carcinoma (SCC). * **Regular follow-up:** These patients require lifelong surveillance due to the high risk of malignant transformation in the dysplastic epithelium. **NEET-PG High-Yield Pearls:** * **Leukoplakia** (white patch) and **Erythroplakia** (red patch) are clinical terms, not histological diagnoses. * **Keratosis Pharyngeus** involves the tonsils/pharynx, whereas **Laryngeal Keratosis** is a precursor to glottic SCC. * The management ladder for laryngeal dysplasia: Smoking cessation → MLS with excisional biopsy (stripping) → Close follow-up. Radical surgery is reserved for confirmed invasive malignancy.

Question 186: Which of the following can be produced by reflux laryngitis?

A. Subglottic stenosis (Correct Answer)
B. Carcinoma of the larynx
C. Cord fixation
D. Acute supraglottitis

Explanation: **Explanation:** **Reflux Laryngitis** (Laryngopharyngeal Reflux - LPR) occurs when gastric contents, including acid and pepsin, backflow into the larynx. Unlike the esophagus, the laryngeal mucosa lacks protective mechanisms against acid, leading to chronic inflammation and tissue damage. **Why Subglottic Stenosis is the correct answer:** Chronic exposure to gastric acid causes persistent mucosal irritation, ulceration, and subsequent granulation tissue formation. In the subglottic region—the narrowest part of the upper airway—this inflammatory process leads to **fibrosis and scarring**, which can result in acquired **Subglottic Stenosis**. LPR is considered a significant co-factor in the failure of surgical repairs for stenosis and is a known etiologic factor in idiopathic cases. **Analysis of Incorrect Options:** * **B. Carcinoma of the larynx:** While chronic irritation is a risk factor, LPR is primarily associated with benign inflammatory changes (like contact granulomas). Tobacco and Alcohol remain the primary definitive precursors for laryngeal SCC. * **C. Cord fixation:** Reflux can cause vocal cord edema (Reinke’s edema) or granulomas, but it does not typically cause true cricoarytenoid joint ankylosis or nerve paralysis required for "fixation." * **D. Acute supraglottitis:** This is an acute bacterial infection (typically *H. influenzae*) characterized by rapid onset and "cherry red" epiglottis, not a chronic inflammatory condition like reflux. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site of LPR:** Posterior commissure (Interarytenoid pachyderma). * **Common findings:** Contact ulcers/granulomas, pseudosulcus vocalis, and subglottic stenosis. * **Diagnosis:** Gold standard is **24-hour double-probe pH monitoring**. * **Treatment:** Lifestyle modification and aggressive Proton Pump Inhibitor (PPI) therapy (usually twice daily for 3–6 months).

Question 187: Which of the following laryngeal malignancies shows the least lymph node involvement?

A. Supraglottic carcinoma
B. Subglottic carcinoma
C. Glottic carcinoma (Correct Answer)
D. Carcinoma of the nasopharynx

Explanation: **Explanation:** The correct answer is **Glottic carcinoma**. The primary reason for the low incidence of lymphatic spread in glottic cancer is the unique anatomical distribution of lymphatics in the larynx. **1. Why Glottic Carcinoma is the correct answer:** The vocal folds (glottis) are characterized by a **paucity of lymphatic drainage**. The free edge of the vocal cord is virtually devoid of lymphatics (Reinke’s space). Consequently, glottic tumors remain localized for a long duration. Furthermore, because even small tumors on the vocal cords cause early symptoms like **hoarseness of voice**, these patients present early (Stage I/II), further reducing the statistical likelihood of finding nodal metastasis at the time of diagnosis. **2. Why other options are incorrect:** * **Supraglottic carcinoma:** This region has a **rich, bilateral lymphatic network**. Approximately 40-50% of patients present with palpable cervical lymph nodes (most commonly Level II, III, and IV) at the time of diagnosis. * **Subglottic carcinoma:** While rarer than glottic cancer, the subglottis has a significant lymphatic supply that drains to the **pre-laryngeal (Delphian)** and paratracheal nodes. It often presents at an advanced stage. * **Carcinoma of the nasopharynx:** This is notorious for **early and frequent lymphatic spread** (often bilateral) due to the dense lymphatic plexus in the nasopharyngeal mucosa. **Clinical Pearls for NEET-PG:** * **Most common site** of laryngeal cancer: Glottis. * **Best prognosis** in laryngeal cancer: Glottic (due to early detection and poor lymphatics). * **Worst prognosis** in laryngeal cancer: Subglottic (due to late presentation and silent spread). * **Delphian Node:** The prelaryngeal node, often involved in subglottic or anterior commissure spread.

Question 188: What is the typical resting position of a vocal cord in a cadaver?

A. Median
B. Paramedian
C. Intermediate (Correct Answer)
D. Full Abduction

Explanation: **Explanation:** The position of the vocal cords is determined by the balance of intrinsic laryngeal muscles. In a **cadaver**, all neuro-muscular activity ceases, and the vocal cords assume a neutral, passive position known as the **Intermediate (or Cadaveric) position**. **1. Why Intermediate is Correct:** In this position, the vocal cords are approximately **3.5 mm** away from the midline. This occurs because there is a total absence of both adductory and abductory forces. It is the "zero-point" of the larynx where the vocal folds are neither tensed nor moved by any active muscle contraction. **2. Analysis of Incorrect Options:** * **Median (0 mm):** This is the position during phonation. It is also seen in bilateral recurrent laryngeal nerve (RLN) palsy with intact cricothyroids (Semon’s Law). * **Paramedian (1.5 mm):** This is the typical position in **isolated Recurrent Laryngeal Nerve (RLN) palsy**. The cricothyroid muscle (supplied by the Superior Laryngeal Nerve) remains intact and acts as a compensatory adductor, pulling the cord toward the midline. * **Full Abduction (7-9 mm):** This occurs during deep inspiration or forced breathing, requiring active contraction of the Posterior Cricoarytenoid (PCA) muscle. **3. Clinical Pearls for NEET-PG:** * **Semon’s Law:** States that in progressive lesions of the RLN, abductor fibers are injured first; hence the cord moves from midline to lateral as the paralysis progresses. * **Wagner and Grossman Hypothesis:** Explains that if the Superior Laryngeal Nerve is also paralyzed (Combined Palsy), the cord shifts from paramedian to the **Intermediate position** because the cricothyroid can no longer adduct it. * **High-Yield Sequence:** Median (Phonation) → Paramedian (RLN Palsy) → Intermediate (Cadaveric/Combined Palsy) → Full Abduction (Deep Inspiration).

Question 189: Which type of laryngoscope blade is curved?

A. Miller
B. Macintosh (Correct Answer)
C. Muller
D. Merkel

Explanation: **Explanation:** In clinical practice and anesthesia, laryngoscope blades are primarily categorized into two types based on their shape and the anatomical landmark they target: **Curved** and **Straight**. 1. **Macintosh Blade (Correct Answer):** This is the most commonly used **curved blade**. It is designed to be inserted into the **vallecula** (the space between the base of the tongue and the epiglottis). By applying upward pressure on the hyoepiglottic ligament, the epiglottis is lifted indirectly to reveal the glottis. It is preferred in adults as it provides more room for endotracheal tube passage and causes less trauma to the epiglottis. 2. **Miller Blade (Incorrect):** This is a **straight blade**. Unlike the Macintosh, it is designed to be passed over the posterior surface of the epiglottis to lift it **directly**. It is the preferred choice in infants and young children who have a long, floppy, U-shaped epiglottis. 3. **Muller and Merkel (Incorrect):** These are distractors. While "Müller’s maneuver" is a clinical test used in ENT to assess airway collapse in obstructive sleep apnea, there is no standard "Muller" or "Merkel" laryngoscope blade used in routine intubation. **High-Yield Clinical Pearls for NEET-PG:** * **Placement:** Macintosh = Vallecula (Indirect lift); Miller = Epiglottis (Direct lift). * **Pediatric Airway:** The Miller blade is superior in neonates because their epiglottis is more horizontal and flexible. * **Jackson’s Laryngoscope:** A rigid, hollow tube used for direct laryngoscopy in ENT procedures, distinct from the folding anaesthetic laryngoscopes mentioned above. * **Difficult Airway:** In cases of "difficult intubation," video laryngoscopes (e.g., McGrath or Glidescope) are now frequently utilized.

Question 190: What is the most common site for a contact ulcer in the larynx?

A. Arytenoids (Correct Answer)
B. Corniculate cartilage
C. Anterior one-third of the vocal cord
D. Cricoid cartilage

Explanation: **Explanation:** **1. Why Arytenoids is the Correct Answer:** Contact ulcers (also known as contact granulomas) occur due to mechanical trauma or chemical irritation to the mucosal lining covering the **vocal process of the arytenoid cartilage**. This area is the most posterior part of the glottis. Unlike the anterior two-thirds of the vocal cords, which are membranous, the posterior one-third is cartilaginous. The mucosa here is extremely thin and tightly stretched over the firm arytenoid cartilage, making it highly susceptible to pressure necrosis and ulceration from forceful "throat clearing," coughing, or the "hammer-and-anvil" effect of loud, low-pitched phonation (often seen in "Preacher’s nodes" or "Singer’s nodes" counterparts). **2. Why the Other Options are Incorrect:** * **Corniculate cartilage:** These are small accessory cartilages located at the apex of the arytenoids within the aryepiglottic folds; they do not participate in vocal cord apposition and are not sites for contact ulcers. * **Anterior one-third of the vocal cord:** This is the classic site for **Vocal Nodules** (Singer’s Nodules), which occur at the junction of the anterior 1/3 and posterior 2/3 of the membranous cord. * **Cricoid cartilage:** This forms a complete ring and is located below the level of the glottis. It is not involved in the phonatory trauma that causes contact ulcers. **3. Clinical Pearls for NEET-PG:** * **Etiology:** The "Triple Threat" causes are **Vocal abuse** (shouting), **Laryngopharyngeal Reflux (LPR)**, and **Endotracheal Intubation** trauma. * **Clinical Presentation:** Patients present with hoarseness, "a bone in the throat" sensation (globus), and referred ear pain (otalgia). * **Management:** Conservative management is preferred—Voice therapy and aggressive Anti-reflux medication (PPIs). Surgery is avoided as it often leads to recurrence. * **Biopsy:** Only indicated if malignancy is suspected (to rule out squamous cell carcinoma).

Practice by Chapter

Acute Laryngitis

Practice Questions

Chronic Laryngitis

Practice Questions

Vocal Cord Nodules and Polyps

Practice Questions

Reinke's Edema

Practice Questions

Laryngeal Papillomatosis

Practice Questions

Vocal Cord Paralysis

Practice Questions

Laryngeal Trauma

Practice Questions

Laryngeal Stenosis

Practice Questions

Laryngeal Cancer

Practice Questions

Laryngomalacia

Practice Questions

Epiglottitis

Practice Questions

Voice Disorders

Practice Questions

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