Diseases of the Larynx

Diseases of the Larynx Indian Medical PG Question 1: True about carcinoma of the larynx?

• A. Glottis is the most common site. (Correct Answer)
• B. It rarely presents with metastasis.
• C. Adenocarcinoma is the commonest type.
• D. It responds to chemotherapy very well.

Diseases of the Larynx Explanation: ### 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).

Diseases of the Larynx Indian Medical PG Question 2: Which of the following is NOT used in the treatment of Juvenile Laryngeal Papillomatosis?

• A. Interferon alpha (INF α)
• B. Interferon beta (INF β) (Correct Answer)
• C. Bevacizumab
• D. Cedofovir

Diseases of the Larynx Explanation: **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.

Diseases of the Larynx Indian Medical PG Question 3: What is the standard treatment for T1N0M0 laryngeal cancer?

• A. Radiotherapy (Correct Answer)
• B. Total laryngectomy
• C. Laser therapy
• D. Microlaryngoscopic surgery

Diseases of the Larynx Explanation: **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.

Diseases of the Larynx Indian Medical PG Question 4: Dead space is reduced in tracheostomy by what percentage?

• A. 5-10%
• B. 15-20%
• C. 20-30%
• D. 30-50% (Correct Answer)

Diseases of the Larynx Explanation: ### 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.

Diseases of the Larynx Indian Medical PG Question 5: For foreign bodies retained in the larynx causing choking, what is the first-line management?

• A. Airway intubation
• B. Heimlich maneuver (Correct Answer)
• C. Heimlich valve
• D. Tracheostomy

Diseases of the Larynx Explanation: **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.

Diseases of the Larynx Flashcard 1 of 5

Question: The given lesion of the vocal cords is a laryngeal _____

Answer: papilloma

Diseases of the Larynx Flashcard 2 of 5

Question: Type _____ thyroplasty or lateralization is done for RLN palsy

Answer: II

Diseases of the Larynx Flashcard 3 of 5

Question: Laryngeal papillomas are usually _____ lesions in adults

Answer: single

Diseases of the Larynx Flashcard 4 of 5

Question: Biphasic stridor is seen in lesions of _____, subglottis and cervical trachea

Answer: glottis

Diseases of the Larynx Flashcard 5 of 5

Question: Since _____ is supplied by SLN, it is spared in RLN palsy and causes mild adduction, this theory is known as Wagner and Grossman theory

Answer: cricothyroid