Diseases of the Larynx Practice Questions

Q: What is the subglottic diameter less than which is considered subglottic stenosis in term infants?

4 mm. ### Explanation **Subglottic stenosis (SGS)** is defined as a narrowing of the subglottic airway, which is the narrowest part of the pediatric airway (at the level of the cricoid cartilage). **1. Why 4 mm is the Correct Answer:** In a healthy, full-term neonate, the normal subglottic diameter is approximately **4.5 to 5 mm**. According to the standard clinical definition, subglottic stenosis is diagnosed when the diameter of the subglottis is **less than 4 mm** in a full-term infant. In premature infants, the threshold is lower, typically considered less than **3 mm**. **2. Analysis of Incorrect Options:** * **Option A (2 mm):** This represents a critical, life-threatening narrowing. While it is technically stenosis, it is far below the diagnostic threshold. * **Option B (3 mm):** This is the diagnostic cutoff for **premature infants**, but not for term infants. * **Option D (5 mm):** This is considered the lower limit of the **normal range** for a term infant. **3. Clinical Pearls for NEET-PG:** * **Most Common Cause:** Congenital SGS is the third most common congenital anomaly of the larynx (after laryngomalacia and vocal cord paralysis). However, **acquired SGS** (due to prolonged endotracheal intubation) is more common overall. * **Grading System:** The **Cotton-Myer Classification** is used to grade the severity based on the percentage of lumen reduction: * Grade I: <50% obstruction * Grade II: 51–70% * Grade III: 71–99% * Grade IV: No detectable lumen (complete atresia) * **Clinical Presentation:** The hallmark sign is **biphasic stridor**. * **Management:** Mild cases (Grade I/II) may be managed conservatively; severe cases (Grade III/IV) often require surgical intervention like **Laryngotracheal Reconstruction (LTR)** or **Cricotracheal Resection (CTR)**.

Q: All of the following are true about adult laryngeal papilloma except:

Typically found in the posterior half of the vocal cord. **Explanation:** Laryngeal papillomas are benign epithelial tumors caused by Human Papillomavirus (HPV types 6 and 11). They are classified into Juvenile-onset and Adult-onset types, which have distinct clinical profiles. **Why Option C is the Correct Answer (The False Statement):** Laryngeal papillomas, especially the adult variety, typically involve the **anterior half** of the vocal cords or the anterior commissure. They tend to occur at "junctional zones" where ciliated columnar epithelium meets squamous epithelium. Finding a lesion primarily in the posterior larynx is atypical and should raise suspicion for other pathologies like contact granulomas or tuberculosis. **Analysis of Other Options:** * **Option A (More common in males):** Unlike the juvenile form (which has an equal sex distribution), adult-onset laryngeal papilloma shows a significant **male preponderance**. * **Option B (Do not recur):** While adult papillomas are often solitary, they **frequently recur** after surgery. Although the recurrence rate is lower than in the juvenile-onset respiratory papillomatosis (JORP), multiple sittings are often required. * **Option D (Treatment is primarily surgical):** The gold standard treatment is **Microlaryngeal Surgery (MLS)** using CO2 laser or microdebrider to debulk the lesion while preserving the underlying vocal cord structure. **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** HPV 6 and 11 (Low risk for malignancy, though adult types have a slightly higher risk of malignant transformation than juvenile types). * **Presentation:** Hoarseness of voice is the most common presenting symptom. * **Adjuvant Therapy:** Cidofovir (intralesional injection) is the most common adjuvant used for aggressive recurrences. * **Key Difference:** Juvenile type is often multiple and aggressive; Adult type is usually solitary and less aggressive.

Q: Which of the following can cause bilateral recurrent laryngeal nerve palsy?

Thyroid surgery, thyroid malignancy, and viral infection. **Explanation:** Recurrent Laryngeal Nerve (RLN) palsy can be unilateral or bilateral. For a condition to cause **bilateral** palsy, it must either involve a midline structure, affect both sides of the neck/mediastinum simultaneously, or be a systemic process. 1. **Why Option B is correct:** * **Thyroid Surgery:** This is the most common cause of bilateral RLN injury. During total thyroidectomy, both nerves are at risk due to their proximity to the gland. * **Thyroid Malignancy:** Advanced thyroid carcinoma (especially anaplastic or invasive papillary) can infiltrate both nerves as they ascend in the tracheoesophageal groove. * **Viral Infection:** Post-viral neuritis (e.g., following Influenza or Herpes) can cause idiopathic bilateral vocal cord paralysis, often presenting as sudden onset airway compromise. 2. **Why other options are incorrect:** * **Aneurysm of the Arch of Aorta (Options A & C):** This is a classic cause of **unilateral** (left-sided) RLN palsy (Ortner’s syndrome). The left RLN loops under the aortic arch, while the right RLN loops under the subclavian artery. An aortic aneurysm cannot anatomically cause bilateral palsy unless there is a separate pathology on the right side. * **Option D:** While correct, it is incomplete. Viral infections are a recognized clinical etiology for bilateral involvement. **High-Yield Clinical Pearls for NEET-PG:** * **Position of cords:** In bilateral RLN palsy, cords usually lie in the **median or paramedian position** because the cricothyroid muscle (supplied by the Superior Laryngeal Nerve) is still functional and adducts the cords. * **Clinical Presentation:** The primary symptom of bilateral RLN palsy is **stridor and dyspnea**, whereas the primary symptom of unilateral palsy is **hoarseness**. * **Management:** Acute bilateral palsy is a medical emergency often requiring **tracheostomy** to secure the airway.

Q: Which drug is locally used for tracheal stenosis?

Mitomycin C. **Explanation:** **Mitomycin C (Option A)** is the correct answer. It is a potent fibroblast inhibitor and an alkylating agent derived from *Streptomyces caespitosus*. In the management of tracheal or subglottic stenosis, it is used topically (usually at a concentration of 0.4 mg/ml) following endoscopic dilation or laser resection. Its primary mechanism is the inhibition of DNA synthesis, which prevents the proliferation of fibroblasts and the synthesis of collagen. This reduces the formation of excessive scar tissue (granulation), thereby maintaining the patency of the airway and decreasing the rate of restenosis. **Why the other options are incorrect:** * **Doxorubicin (Option B):** An anthracycline chemotherapy agent used systemically for various malignancies (e.g., breast cancer, lymphomas). It has no established role in the local management of airway stenosis. * **Bleomycin (Option C):** While used intralesionally for hemangiomas or warts, it is not the standard of care for tracheal stenosis. Its primary side effect is pulmonary fibrosis, making it unsuitable for this specific application. * **Clindamycin (Option D):** A lincosamide antibiotic used to treat anaerobic infections. It does not possess the anti-fibrotic properties required to prevent cicatricial stenosis. **High-Yield Clinical Pearls for NEET-PG:** * **Application:** Mitomycin C is applied topically via a soaked cottonoid for 2–5 minutes. * **Other ENT uses:** It is also used topically in **Dacryocystorhinostomy (DCR)** and **Myringotomy** to prevent the closure of the surgical stoma/opening. * **Adjuvant Therapy:** In tracheal stenosis, it is often used alongside **systemic or intralesional steroids** (like Triamcinolone) to further suppress inflammation.

Q: The "TURBAN" epiglottis is pathognomic of which condition?

Sarcoidosis. ### Explanation The correct answer is **Sarcoidosis**. **1. Why Sarcoidosis is Correct:** Laryngeal sarcoidosis occurs in approximately 1–5% of patients with systemic sarcoidosis. The disease typically involves the supraglottic structures, most notably the **epiglottis**. The underlying pathology involves non-caseating granulomatous infiltration, which causes the epiglottis to become pale, edematous, and massively thickened. This characteristic rounded, swollen appearance is classically described as a **"Turban-shaped" epiglottis**. Patients usually present with hoarseness, dysphagia, or airway obstruction rather than pain. **2. Analysis of Incorrect Options:** * **Wegener’s Granulomatosis (Granulomatosis with Polyangiitis):** This condition primarily affects the **subglottic** region (Subglottic Stenosis) rather than the epiglottis. It is characterized by necrotizing granulomas and vasculitis. * **Histoplasmosis:** Fungal infections of the larynx typically present with painful ulcerations, heaped-up mucosa, or "millet-seed" nodules. They do not produce the uniform turban-like swelling seen in sarcoidosis. * **Malignancy:** Laryngeal carcinoma (Squamous Cell Carcinoma) usually presents as an exophytic mass or an infiltrative ulcer. While it can cause swelling, it is typically asymmetric and associated with friability or vocal cord fixation. **3. High-Yield Clinical Pearls for NEET-PG:** * **Turban Epiglottis:** Sarcoidosis. * **Omega-shaped Epiglottis:** Laryngomalacia (most common cause of congenital stridor). * **Leaf-like/Normal Epiglottis:** Often seen in Laryngeal Tuberculosis (though TB can also cause a "pseudo-turban" appearance, Sarcoidosis is the classic textbook association for "Turban"). * **Cherry Red Epiglottis:** Acute Epiglottitis (caused by *H. influenzae*). * **Subglottic Stenosis:** Most common laryngeal manifestation of Wegener’s Granulomatosis.

Q: A 6-month-old baby presents with loud, noisy breathing since birth, particularly noticeable when feeding in a supine position. The birth history is otherwise unremarkable. What is the recommended management for this condition?

Reassurance. ### Explanation **Diagnosis: Laryngomalacia** The clinical presentation describes **Laryngomalacia**, the most common cause of congenital stridor in infants. It is characterized by an inspiratory "crowing" sound (stridor) caused by the collapse of supraglottic structures (e.g., omega-shaped epiglottis) during inspiration. The stridor typically worsens when the infant is **supine**, crying, or feeding, and improves when prone. **Why Reassurance is Correct:** In more than 90% of cases, laryngomalacia is a self-limiting condition. The stridor usually peaks at 6 months and resolves spontaneously by 18–24 months as the airway cartilage matures and strengthens. Unless there is evidence of "danger signs" (failure to thrive, cyanosis, or severe respiratory distress), the standard management is **conservative observation and reassurance** to the parents. **Why Other Options are Incorrect:** * **A. 3rd generation cephalosporins:** These are used for bacterial infections like Epiglottitis. Laryngomalacia is a structural/developmental anomaly, not an infection. * **B. Heimlich’s maneuver:** This is an emergency intervention for acute foreign body airway obstruction, which would present with sudden onset choking, not a chronic sound present since birth. * **D. Single dose of Dexamethasone:** Steroids are the mainstay for **Croup (Laryngotracheobronchitis)** to reduce subglottic edema. They have no role in treating the structural collapse seen in laryngomalacia. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of inspiratory stridor in neonates:** Laryngomalacia. * **Classic finding on laryngoscopy:** "Omega-shaped" (Ω) epiglottis with short aryepiglottic folds. * **Definitive Diagnosis:** Flexible fiberoptic laryngoscopy (showing inward collapse of supraglottic tissues). * **Surgical Indication:** If severe (cor pulmonale, apnea, or poor weight gain), the procedure of choice is **Supraglottoplasty**.

Q: What is seen after tracheostomy?

Decreased in dead space. **Explanation:** Tracheostomy is a surgical procedure that creates an opening in the trachea, bypassing the upper respiratory tract (nose, pharynx, and larynx). **Why "Decreased in dead space" is correct:** The primary physiological effect of a tracheostomy is the reduction of **anatomical dead space** by approximately **30% to 50%**. By bypassing the upper airway, the volume of air that does not participate in gas exchange is significantly reduced. This improves alveolar ventilation and reduces the work of breathing, which is particularly beneficial in patients with respiratory failure. **Analysis of Incorrect Options:** * **A & B (V/P Ratio):** The Ventilation/Perfusion (V/Q) ratio is primarily determined by pulmonary blood flow and alveolar ventilation at the capillary level. While tracheostomy improves ventilation, it does not inherently "invert" or predictably increase the ratio across the entire lung in a way that defines the procedure's primary physiological hallmark. * **D (Increased resistance):** Tracheostomy actually **decreases** airflow resistance. The upper airway (especially the nose and glottis) accounts for a large portion of total airway resistance. Bypassing these structures with a wider, shorter tube makes it easier for air to reach the lungs. **High-Yield Clinical Pearls for NEET-PG:** * **Dead Space Reduction:** Tracheostomy reduces dead space by ~150ml in adults. * **Indications:** Respiratory failure, upper airway obstruction (e.g., laryngeal edema, tumors), and protection of the tracheobronchial tree (e.g., bulbar palsy). * **Immediate Complication:** Hemorrhage (most common), Apnea (due to sudden washout of $CO_2$ in chronic retainers), and Pneumothorax. * **Late Complication:** Tracheal stenosis (most common at the site of the cuff or stoma).

Question 1

Which of the following is NOT a contraindication for bronchoscopy?

Accepted Answer

Active bleeding

Answer

Lesions of the cervical spine

Answer

Cardiac failure

Answer

Trismus

Question 2

When caring for a male patient who has just had a total laryngectomy, what should the nurse plan to do?

Accepted Answer

Develop an alternative communication method

Answer

Encourage oral feeding as soon as possible

Answer

Keep the tracheostomy cuff fully inflated

Answer

Keep the patient flat in bed

Question 3

What is the subglottic diameter less than which is considered subglottic stenosis in term infants?

Accepted Answer

4 mm

Answer

2 mm

Answer

3 mm

Answer

5 mm

Question 4

All of the following are true about adult laryngeal papilloma except:

Accepted Answer

Typically found in the posterior half of the vocal cord

Answer

More common in males than females

Answer

Do not recur

Answer

Treatment is primarily surgical

Question 5

A 10-year-old boy developed hoarseness of voice following an attack of diphtheria. On examination, his right vocal cord was paralyzed. What is the treatment of choice for a paralyzed vocal cord in this scenario?

Accepted Answer

Wait for spontaneous recovery of the vocal cord

Answer

Gel foam injection of the right vocal cord

Answer

Fat injection of the right vocal cord

Answer

Thyroplasty type-I

Question 6

Which of the following can cause bilateral recurrent laryngeal nerve palsy?

Accepted Answer

Thyroid surgery, thyroid malignancy, and viral infection

Answer

Thyroid surgery, aneurysm of the arch of aorta, and viral infection

Answer

Thyroid surgery, thyroid malignancy, and aneurysm of the arch of aorta

Answer

Thyroid surgery and thyroid malignancy

Question 7

Which drug is locally used for tracheal stenosis?

Accepted Answer

Mitomycin C

Answer

Doxorubicin

Answer

Bleomycin

Answer

Clindamycin

Question 8

The "TURBAN" epiglottis is pathognomic of which condition?

Accepted Answer

Sarcoidosis

Answer

Wegener's granulomatosis

Answer

Histoplasmosis

Answer

Malignancy

Question 9

A 6-month-old baby presents with loud, noisy breathing since birth, particularly noticeable when feeding in a supine position. The birth history is otherwise unremarkable. What is the recommended management for this condition?

Accepted Answer

Reassurance

Answer

3rd generation cephalosporins

Answer

Heimlich's maneuver

Answer

Single dose of Dexamethasone

Question 10

What is seen after tracheostomy?

Accepted Answer

Decreased in dead space

Answer

Inversion of V/P ratio

Answer

Increased V/P ratio

Answer

Increased resistance of air flow

Diseases of the Larynx — MCQs

Diseases of the Larynx — MCQs

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