Diseases of the Larynx Practice Questions

Q: True about carcinoma of the larynx?

Glottis is the most common site.. ### Explanation **Correct Option: A. Glottis is the most common site.** In the Indian subcontinent and globally, the **glottis (vocal cords)** is the most common site for laryngeal carcinoma (approx. 60-65%), followed by the supraglottis (30-35%) and the subglottis (1-5%). Glottic tumors often present early due to hoarseness of voice, which occurs even with tiny lesions. **Analysis of Incorrect Options:** * **B. It rarely presents with metastasis:** This is incorrect. While glottic cancers have a low rate of metastasis due to sparse lymphatic drainage, **supraglottic cancers** have a rich lymphatic network and frequently present with early cervical lymph node metastasis (often bilateral). * **C. Adenocarcinoma is the commonest type:** Incorrect. Over 95% of laryngeal cancers are **Squamous Cell Carcinomas (SCC)**. Adenocarcinoma is rare and usually arises from minor salivary glands. * **D. It responds to chemotherapy very well:** Incorrect. The primary treatment modalities for laryngeal cancer are **Surgery and Radiotherapy**. Chemotherapy is typically used as an adjuvant or for "organ preservation" protocols (e.g., Cisplatin) rather than being the definitive treatment of choice. **High-Yield Clinical Pearls for NEET-PG:** * **Best Prognosis:** Glottic cancer (due to early symptoms and poor lymphatics). * **Worst Prognosis:** Subglottic cancer (presents late and has a high risk of paratracheal node involvement). * **Most Common Site of Distant Metastasis:** Lungs. * **Staging:** T1a involves one vocal cord; T1b involves both cords. T3 implies vocal cord fixation. * **Risk Factors:** Smoking (strongest association) and Alcohol (synergistic effect).

Q: Which of the following is NOT used in the treatment of Juvenile Laryngeal Papillomatosis?

Interferon beta (INF β). **Explanation:** Juvenile Laryngeal Papillomatosis (JLP), caused by **HPV types 6 and 11**, is characterized by recurrent benign epithelial tumors. The primary treatment is surgical debulking (CO2 laser or microdebrider), but adjuvant medical therapy is indicated when the disease is aggressive (requiring >4 surgeries per year). **Why Option B is Correct:** **Interferon beta (INF β)** is not a standard treatment for JLP. While Interferons have antiviral and antiproliferative properties, clinical evidence and established protocols specifically utilize **Interferon alpha (INF α)**. INF β does not have a proven role in the management of this condition. **Analysis of Incorrect Options:** * **Interferon alpha (INF α):** Historically the first-line adjuvant therapy. It slows the rate of recurrence by inducing antiviral states in cells, though it rarely provides a permanent cure and has significant side effects (flu-like symptoms, growth retardation). * **Cidofovir:** A potent antiviral (cytosine nucleotide analog) administered via **intralesional injection**. It is currently one of the most commonly used adjuvant agents for recalcitrant cases. * **Bevacizumab:** An anti-VEGF monoclonal antibody. It is a newer, highly effective treatment (administered systemically or intralesionally) that inhibits the angiogenesis required for papilloma growth. **High-Yield Clinical Pearls for NEET-PG:** * **Most common benign tumor** of the larynx in children. * **Triad of symptoms:** Hoarseness (most common), stridor, and respiratory distress. * **Diagnosis:** Direct laryngoscopy shows "cauliflower-like" masses. * **Gold Standard Adjuvant:** Cidofovir (Intralesional). * **Newer Trend:** Bevacizumab is increasingly preferred for severe cases. * **Note:** Tracheostomy should be avoided as it may lead to "stomal seeding" of the papilloma.

Q: What is the standard treatment for T1N0M0 laryngeal cancer?

Radiotherapy. **Explanation:** The management of early-stage laryngeal cancer (T1N0M0) focuses on **organ preservation** and maintaining voice quality. For T1 lesions, both **Radiotherapy (RT)** and **Endoscopic CO2 Laser Excision** are considered standard treatments, as they offer similar local control and survival rates (approx. 90-95%). **Why Radiotherapy is the Correct Answer:** In the context of standard examinations like NEET-PG, **Radiotherapy** is traditionally favored as the primary answer for T1 glottic lesions because it provides an excellent functional outcome with a superior voice quality compared to surgery. It treats the entire larynx, addressing potential multicentricity of the disease without the need for surgical margins. **Analysis of Incorrect Options:** * **B. Total Laryngectomy:** This is a radical procedure reserved for advanced stages (T3 or T4) where the larynx is non-functional or there is extensive cartilage destruction. It is never the first-line treatment for T1 disease. * **C. Laser Therapy:** While highly effective and increasingly popular (Transoral Laser Microsurgery - TLM), it is often considered an alternative to RT. In many textbooks, RT remains the "classic" gold standard for voice preservation in T1. * **D. Microlaryngoscopic Surgery:** While used for biopsy or very superficial "stripping," it is generally insufficient as a standalone curative treatment for invasive T1 cancer unless performed via CO2 laser (TLM). **Clinical Pearls for NEET-PG:** * **T1a:** Involves one vocal cord; **T1b:** Involves both vocal cords. * **Voice Quality:** RT generally offers a better "smooth" voice, whereas Laser surgery may result in a "breathy" or "rough" voice due to tissue loss. * **Salvage:** If RT fails, surgery (Partial or Total Laryngectomy) can still be performed. * **Treatment of Choice for T3/T4:** Concurrent Chemoradiotherapy (for organ preservation) or Total Laryngectomy.

Q: Dead space is reduced in tracheostomy by what percentage?

30-50%. ### Explanation **Concept:** Tracheostomy reduces the **anatomical dead space**—the volume of the conducting airways where no gas exchange occurs (nose, pharynx, larynx, and upper trachea). By creating an opening in the neck and bypassing the upper respiratory tract, the inspired air travels a significantly shorter distance to reach the alveoli. **Why 30-50% is Correct:** In a healthy adult, the anatomical dead space is approximately **150 ml**. A tracheostomy bypasses the entire upper airway, which accounts for nearly half of this volume. Standard medical literature and ENT textbooks (like Dhingra) state that a tracheostomy reduces this dead space by **30% to 50%**. This reduction is clinically significant as it improves alveolar ventilation and reduces the work of breathing, especially in patients with respiratory failure or chronic lung disease. **Analysis of Incorrect Options:** * **A (5-10%) & B (15-20%):** These values are too low. Bypassing the entire oral/nasal cavity and the larynx removes a much larger proportion of the conducting pathway than these percentages suggest. * **C (20-30%):** While closer, this underestimates the contribution of the upper airway to the total dead space volume. **High-Yield Clinical Pearls for NEET-PG:** * **Physiological Effects of Tracheostomy:** 1. **Reduced Dead Space:** (30-50%) Improves ventilation efficiency. 2. **Reduced Resistance:** Decreases the work of breathing. 3. **Bypasses Laryngeal Protection:** Increases the risk of aspiration. 4. **Loss of Humidification:** Leads to crusting and ciliary dysfunction (requires external humidification). * **Dead Space Calculation:** Anatomical dead space is roughly **2 ml/kg** of body weight. * **Key Indication:** Tracheostomy is indicated when "prolonged intubation" is expected (usually >7-14 days) to prevent subglottic stenosis.

Q: For foreign bodies retained in the larynx causing choking, what is the first-line management?

Heimlich maneuver. **Explanation:** The **Heimlich maneuver** (subdiaphragmatic abdominal thrusts) is the gold-standard first-line emergency management for an upper airway obstruction caused by a foreign body. The physiological principle is to create an **"artificial cough"** by elevating the diaphragm, which increases intrathoracic pressure and forces air out of the lungs to expel the obstructing object. **Analysis of Options:** * **Heimlich Maneuver (Correct):** It is non-invasive, requires no equipment, and is the immediate step for a conscious choking victim. * **Airway Intubation (Incorrect):** Intubation is technically difficult or impossible if a foreign body is physically blocking the laryngeal inlet. Attempting it may push the object further down. * **Heimlich Valve (Incorrect):** This is a one-way valve used in the management of a pneumothorax to allow air to exit the pleural space; it has no role in airway obstruction. * **Tracheostomy (Incorrect):** While it provides a definitive surgical airway, it is time-consuming and considered only if non-invasive maneuvers (Heimlich) and basic life support (cricothyroidotomy) fail. **High-Yield Clinical Pearls for NEET-PG:** * **In Infants (<1 year):** Abdominal thrusts are contraindicated due to the risk of liver injury. Use **5 back blows and 5 chest thrusts** instead. * **In Pregnant/Obese Patients:** Use **chest thrusts** (lower sternum) instead of abdominal thrusts. * **Unconscious Patient:** If the patient becomes unresponsive, start **CPR** immediately. The chest compressions serve the dual purpose of circulating blood and providing pressure to dislodge the foreign body. * **Gold Standard Investigation:** For a stable patient with suspected foreign body inhalation, **Rigid Bronchoscopy** is the investigation and treatment of choice.

Q: Which of the following lasers is most commonly used in laryngeal surgery?

CO2 laser. **Explanation:** The **CO2 laser (Carbon Dioxide laser)** is the "gold standard" and most commonly used laser in laryngeal surgery. Its wavelength (10,600 nm) is highly absorbed by water, which constitutes the majority of soft tissue. This results in **excellent precision** with minimal peripheral thermal damage (shallow penetration depth of 0.1 mm). In the larynx, where preserving delicate vocal cord architecture is vital, the CO2 laser allows for "what you see is what you get" surgery, providing a bloodless field and rapid healing. **Analysis of Incorrect Options:** * **Nd:YAG laser:** This has deep tissue penetration (up to 4–5 mm) and excellent hemostatic properties. However, its lack of precision and risk of significant collateral thermal injury make it unsuitable for delicate laryngeal work; it is more commonly used for debulking large tracheobronchial tumors. * **Argon laser:** This is absorbed by hemoglobin and melanin. It is primarily used in otology (e.g., stapedotomy) or ophthalmology, but lacks the versatility required for major laryngeal resections. * **KTP laser (Potassium Titanyl Phosphate):** While used in the larynx for vascular lesions (like laryngeal papillomas or ectasias) because it is selectively absorbed by hemoglobin, it is not the *most common* or primary tool for general laryngeal surgery compared to the CO2 laser. **Clinical Pearls for NEET-PG:** * **Laser Safety:** The most dreaded complication of laryngeal laser surgery is an **airway fire**. To prevent this, surgeons use laser-resistant endotracheal tubes and fill the cuff with saline tinted with **methylene blue** (to signal a cuff breach). * **Mode of delivery:** CO2 lasers are typically delivered via a micromanipulator attached to an operating microscope. * **Key Indication:** CO2 laser is the treatment of choice for **T1 glottic cancer** and **Laryngeal Papillomatosis**.

Q: Which muscle is the primary abductor of the vocal cords?

Posterior cricoarytenoid. **Explanation:** The intrinsic muscles of the larynx are responsible for controlling the tension and position of the vocal cords. 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. Upon contraction, it rotates the arytenoids laterally, opening the rima glottidis. Because it is the sole muscle responsible for opening the airway, it is often referred to as the **"Safety Muscle of the Larynx."** **Analysis of Incorrect Options:** * **Thyroarytenoid:** This muscle makes up the bulk of the vocal folds. Its primary action is to shorten and relax the vocal cords (the vocalis part allows for fine-tuning of pitch). * **Lateral Cricoarytenoid:** This is the primary **adductor** of the vocal cords. It rotates the arytenoids medially to close the glottis for phonation. * **Cricothyroid:** This muscle **tenses** and elongates the vocal cords by tilting the thyroid cartilage forward. It is unique because it is the only intrinsic muscle supplied by the **External Laryngeal Nerve** (all others are supplied by the Recurrent Laryngeal Nerve). **High-Yield Clinical Pearls for NEET-PG:** * **Innervation Rule:** All intrinsic muscles of the larynx are supplied by the **Recurrent Laryngeal Nerve (RLN)**, except the Cricothyroid. * **Semon’s Law:** In progressive RLN injury, the abductor fibers (PCA) are more vulnerable and paralyzed earlier than the adductor fibers. * **Bilateral RLN Palsy:** This is a surgical emergency because the loss of the PCA (abductor) causes the vocal cords to remain in the midline (adducted) position, leading to stridor and airway obstruction.

Q: Recurrent laryngeal nerve palsy produces vocal cord in which position?

Paramedian. ### Explanation The position of the vocal cords in nerve palsies is determined by the **Wagner and Grossman hypothesis**, which states that the cricothyroid muscle (supplied by the Superior Laryngeal Nerve) remains active even if the Recurrent Laryngeal Nerve (RLN) is paralyzed. **Why Paramedian is Correct:** In isolated **Recurrent Laryngeal Nerve (RLN) palsy**, all intrinsic muscles of the larynx are paralyzed except for the **cricothyroid**. The cricothyroid acts as a tensor and a weak adductor of the vocal cord. Its unopposed action pulls the vocal cord toward the midline, resulting in the **paramedian position** (1.5 mm from the midline). **Analysis of Incorrect Options:** * **Cadaveric (Option A):** This occurs in **Combined Palsy** (both RLN and SLN are paralyzed). Without the cricothyroid's adducting force, the cord falls further out into a neutral position (3.5 mm from the midline). * **Abducted (Option B):** This is the position during deep inspiration. It is not seen in RLN palsy because the Posterior Cricoarytenoid (the only abductor) is paralyzed. * **Adducted (Option C):** This is the position during phonation. While the cord is close to the midline in RLN palsy, it is specifically "paramedian" rather than fully adducted. **High-Yield Clinical Pearls for NEET-PG:** * **Semon’s Law:** In progressive lesions of the RLN, abductor fibers are injured first (more vulnerable), leading to an initial adducted position before reaching the paramedian state. * **Unilateral RLN Palsy:** Usually asymptomatic or presents with mild hoarseness as the healthy cord compensates. * **Bilateral RLN Palsy:** Presents with **Stridor** because both cords are in the paramedian position, severely narrowing the glottic airway. * **Most common cause of RLN palsy:** Thyroid surgery (iatrogenic injury).

Question 1

True about carcinoma of the larynx?

Accepted Answer

Glottis is the most common site.

Answer

It rarely presents with metastasis.

Answer

Adenocarcinoma is the commonest type.

Answer

It responds to chemotherapy very well.

Question 2

Which of the following is NOT used in the treatment of Juvenile Laryngeal Papillomatosis?

Accepted Answer

Interferon beta (INF β)

Answer

Interferon alpha (INF α)

Answer

Bevacizumab

Answer

Cedofovir

Question 3

What is the standard treatment for T1N0M0 laryngeal cancer?

Accepted Answer

Radiotherapy

Answer

Total laryngectomy

Answer

Laser therapy

Answer

Microlaryngoscopic surgery

Question 4

Dead space is reduced in tracheostomy by what percentage?

Accepted Answer

30-50%

Answer

5-10%

Answer

15-20%

Answer

20-30%

Question 5

For foreign bodies retained in the larynx causing choking, what is the first-line management?

Accepted Answer

Heimlich maneuver

Answer

Airway intubation

Answer

Heimlich valve

Answer

Tracheostomy

Question 6

Which of the following lasers is most commonly used in laryngeal surgery?

Accepted Answer

CO2 laser

Answer

Nd:YAG laser

Answer

Argon laser

Answer

KTP laser

Question 7

Which muscle is the primary abductor of the vocal cords?

Accepted Answer

Posterior cricoarytenoid

Answer

Thyroarytenoid

Answer

Lateral cricoarytenoid

Answer

Cricothyroid

Question 8

A 75-year-old thin cachectic woman undergoes a tracheostomy for failure to wean from the ventilator. One week later, she develops significant bleeding from the tracheostomy. Which of the following would be an appropriate initial step in the management of this problem?

Accepted Answer

Attempt to reintubate the patient with an endotracheal tube.

Answer

Remove the tracheostomy and place pressure over the wound.

Answer

Deflate the balloon cuff on the tracheostomy.

Answer

Upsize the tracheostomy.

Question 9

Recurrent laryngeal nerve palsy produces vocal cord in which position?

Accepted Answer

Paramedian

Answer

Cadaveric

Answer

Abducted

Answer

Adducted

Question 10

All of the following structures are considered part of the supraglottis in the context of laryngeal cancer, except?

Accepted Answer

All of the above

Answer

Vallecula

Answer

Lower border of cricoid cartilage

Answer

Posterior commissure

Diseases of the Larynx — MCQs

Diseases of the Larynx — MCQs

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