Diseases of the Larynx Practice Questions

Q: What is the commonest cause of hoarseness of voice in an elderly man with a duration of more than 3 months?

Cancer of the larynx. **Explanation:** In any elderly patient, particularly a male with a history of smoking or alcohol use, **persistent hoarseness of voice (dysphonia) for more than 3 weeks** must be considered **Carcinoma of the Larynx** until proven otherwise. The duration of 3 months in this clinical scenario strongly points toward a progressive, neoplastic process rather than an inflammatory or self-limiting one. **Analysis of Options:** * **A. Cancer of the Larynx (Correct):** Glottic cancer (vocal cord) is the most common site and presents early with hoarseness. In the elderly, the risk of malignancy increases significantly, making it the most critical and common diagnosis to rule out in chronic cases. * **B. Chronic Bronchitis:** While it may coexist in smokers, it primarily presents with a productive cough. It does not directly cause hoarseness unless associated with secondary laryngeal irritation or a concurrent malignancy. * **C. Acute Laryngitis:** This is the most common cause of hoarseness *overall*, but it is a self-limiting condition typically lasting less than 1–2 weeks, often following a viral upper respiratory infection. * **D. Nodular Goitre:** While a large goitre can cause pressure symptoms, hoarseness in thyroid disease usually implies malignancy invading the recurrent laryngeal nerve, rather than a simple nodular goitre. **Clinical Pearls for NEET-PG:** * **Rule of 3 Weeks:** Any patient with hoarseness persisting beyond 3 weeks requires a mandatory indirect laryngoscopy (IDL) or fiberoptic laryngoscopy (FOL) to visualize the cords. * **Most common site of Laryngeal Cancer:** Glottis (vocal cords). * **Best Prognosis:** Glottic cancer (due to early presentation and sparse lymphatic drainage). * **Most common pathology:** Squamous Cell Carcinoma (SCC).

Q: Hoarseness with a typical barking cough and biphasic stridor are features of a lesion in which anatomical site?

Larynx. ### Explanation The clinical triad of **hoarseness**, **barking cough**, and **biphasic stridor** is the hallmark of subglottic inflammation, most commonly seen in **Croup (Laryngotracheobronchitis)**. 1. **Why Larynx is Correct:** * **Hoarseness:** Indicates involvement of the vocal cords (glottis). * **Barking Cough:** Result of subglottic edema and turbulent airflow through a narrowed larynx. * **Biphasic Stridor:** Stridor is typically inspiratory in supraglottic lesions and expiratory in tracheal lesions. However, lesions in the **glottis or subglottis** (parts of the larynx) result in **biphasic stridor** because the airway is narrowest here, causing turbulence during both phases of respiration. 2. **Why Other Options are Incorrect:** * **Hypopharynx/Pharynx:** Lesions here typically present with dysphagia, odynophagia, or a "muffled" (hot potato) voice rather than hoarseness. Stridor is rare unless the airway is secondary compressed. * **Trachea:** Tracheal lesions (like a foreign body or tracheomalacia) typically present with **expiratory stridor** or a "wheeze." Hoarseness is absent because the vocal cords are not involved. ### High-Yield Clinical Pearls for NEET-PG: * **Stridor Localization:** * **Inspiratory:** Supraglottic (e.g., Laryngomalacia, Epiglottitis). * **Biphasic:** Glottic/Subglottic (e.g., Croup, Subglottic stenosis). * **Expiratory:** Tracheal/Bronchial (e.g., Foreign body). * **Croup (Laryngotracheobronchitis):** Most common cause of stridor in children (6 months–3 years). Radiologically shows the **"Steeple Sign"** (subglottic narrowing) on AP view of the neck. * **Acute Epiglottitis:** Presents with drooling and a "Thumb sign" on lateral X-ray; hoarseness is usually absent.

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

Bronchogenic cancer. **Explanation:** The Recurrent Laryngeal Nerve (RLN) has a distinct anatomical course on each side. The **right RLN** loops around the subclavian artery in the neck, while the **left RLN** has a much longer intrathoracic course, looping around the arch of the aorta. **Why Bronchogenic Cancer is the correct answer:** While most pathologies (like aortic aneurysms or left-sided tumors) cause isolated left RLN palsy, **bronchogenic carcinoma** is a unique clinical entity that can cause **bilateral** palsy. This occurs because a tumor in the right lung apex (Pancoast tumor) can involve the right RLN, while extensive mediastinal lymphadenopathy (common in lung cancer) or a primary left-sided lesion can simultaneously involve the left RLN. **Analysis of Incorrect Options:** * **Thyroid Cancer & Thyroid Surgery:** These are the most common causes of RLN injury overall. However, they typically present as **unilateral** palsy. Bilateral involvement is rare and usually occurs only in advanced, aggressive undifferentiated cancers or surgical mishaps involving both sides of the neck. * **Aortic Aneurysm:** This specifically causes **left-sided** RLN palsy (Ortner’s Syndrome) because only the left nerve loops under the aortic arch. It cannot anatomically affect the right RLN. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of unilateral RLN palsy:** Thyroid surgery. * **Most common cause of bilateral RLN palsy:** Thyroid surgery (historically) or advanced malignancy (bronchogenic/esophageal). * **Position of cords:** In bilateral complete RLN palsy, both cords lie in the **median or paramedian position**, leading to severe dyspnea and stridor, often requiring an emergency tracheostomy. * **Semon’s Law:** States that in progressive lesions, abductor fibers are injured before adductor fibers.

Q: Bovine cough is characteristic of which of the following conditions?

Laryngeal paralysis. **Explanation:** **Bovine cough** is a characteristic clinical sign of **Recurrent Laryngeal Nerve (RLN) paralysis**, specifically when it is unilateral. **Why Laryngeal Paralysis is correct:** To produce an effective, explosive cough, the vocal cords must first adduct (close) tightly to build up subglottic pressure against a closed glottis. In RLN paralysis, the affected vocal cord remains in a paramedian or abducted position and cannot meet the midline. Consequently, the patient cannot build up subglottic pressure; when they attempt to cough, the air escapes through the glottic gap. This results in a **non-explosive, hollow, and low-pitched cough** that resembles the sound made by a cow (hence "bovine"). **Why other options are incorrect:** * **Acute Epiglottitis:** Characterized by a "muffled" or "hot potato" voice, severe odynophagia, and drooling. Cough is usually absent or minimal. * **Foreign Body Aspiration:** Typically presents with a sudden onset of choking, wheezing, and a "barking" or "croupy" cough if the object is in the trachea. * **Chronic Bronchitis:** Presents with a productive, "smoker’s" cough, usually worse in the morning, but the glottic closure mechanism remains intact, so the cough remains explosive. **High-Yield Clinical Pearls for NEET-PG:** * **Unilateral RLN Paralysis:** Most common cause is **surgical trauma** (e.g., thyroidectomy) or **malignancy** (e.g., apical lung cancer/Pancoast tumor). * **Left vs. Right:** The left RLN is more commonly paralyzed because of its longer intrathoracic course around the arch of the aorta. * **Voice Change:** In unilateral paralysis, the voice is typically **breathy** (weak) due to air escape. * **Bilateral RLN Paralysis:** Presents primarily with **stridor** and respiratory distress rather than bovine cough, as the airway is severely narrowed.

Q: Laryngocele arises from which anatomical structure?

Saccule of the ventricle. **Explanation:** A **Laryngocele** is an abnormal cystic dilatation of the **saccule of the laryngeal ventricle**. The saccule (or appendix of the ventricle) is a blind pouch containing mucous glands, located between the false vocal cords and the inner aspect of the thyroid cartilage. When the neck of this saccule becomes obstructed (due to inflammation or tumors) or when there is chronically increased endolaryngeal pressure (e.g., in trumpet players or glassblowers), it distends with air, forming a laryngocele. **Analysis of Options:** * **Saccule of the ventricle (Correct):** This is the anatomical site of origin. If it contains air, it is a laryngocele; if it fills with mucus, it is a **laryngopyocele**. * **True vocal cords:** These are composed of the vocal ligament and vocalis muscle. They do not possess the glandular saccular structure required to form a laryngocele. * **Subglottis:** This region extends from the vocal cords to the lower border of the cricoid cartilage. While pathologies like subglottic stenosis occur here, laryngoceles originate superiorly in the supraglottic space. * **Anterior commissure:** This is the junction where the two vocal cords meet anteriorly. It is a critical site for the spread of laryngeal cancer but is not the site of origin for cystic dilatations like laryngoceles. **Clinical Pearls for NEET-PG:** 1. **Types:** * *Internal:* Remains within the thyroid cartilage (presents with hoarseness/stridor). * *External:* Pierces the **thyrohyoid membrane** (presents as a neck mass that expands with the Valsalva maneuver). * *Combined:* Features of both. 2. **Bryce’s Sign:** Gurgling sound heard on compression of the external neck mass. 3. **Association:** In adults, always rule out **Squamous Cell Carcinoma** of the ventricle obstructing the saccule.

Q: What is the anterior-posterior diameter of the vocal cords in adult males and females?

23 mm and 17 mm. **Explanation:** The dimensions of the vocal cords (vocal folds) are determined by the overall size of the laryngeal framework, which undergoes significant sexual dimorphism during puberty. In males, the thyroid cartilage enlarges more prominently (forming the "Adam's apple"), leading to a longer anteroposterior (AP) diameter of the glottis compared to females. **1. Why Option C is Correct:** In adult males, the average length of the vocal cord is approximately **23 mm** (ranging from 17–25 mm). In adult females, it is significantly shorter, averaging **17 mm** (ranging from 12–17 mm). This anatomical difference is the primary reason for the lower pitch of the male voice, as longer and thicker cords vibrate at a lower frequency. **2. Why Other Options are Incorrect:** * **Options A, B, and D:** These values (24, 36, 48 mm) are far too large for the human larynx. The entire sagittal diameter of the adult male larynx is only about 36 mm; therefore, the vocal cords themselves cannot be 36 mm or 48 mm. These numbers are likely distractors designed to test the candidate's familiarity with actual laryngeal measurements. **High-Yield Clinical Pearls for NEET-PG:** * **Structure:** The vocal cord consists of the **anterior membranous part** (3/5th) and the **posterior cartilaginous part** (2/5th). * **Infant Larynx:** In newborns, the vocal cord length is only about **6–8 mm**, which explains the high-pitched cry. * **Histology:** The vocal cord is lined by **stratified squamous epithelium** (non-keratinized), unlike the rest of the larynx, which is mostly respiratory epithelium (ciliated columnar). * **Reinke’s Space:** This is a potential space between the vocal ligament and the overlying epithelium; edema here (Reinke’s edema) is common in chronic smokers.

Q: What is the shape of the adult larynx?

Cylindrical. **Explanation:** The shape of the larynx undergoes a significant transformation as an individual matures from infancy to adulthood. **1. Why "Cylindrical" is correct:** In adults, the narrowest part of the larynx is the **rima glottidis** (the space between the vocal cords). The subglottic space below it is relatively wider and uniform. Therefore, the adult larynx is described as **cylindrical** because its diameter remains fairly consistent from the glottis downwards into the trachea. **2. Why the other options are incorrect:** * **Funnel-shaped (Option B):** This is the characteristic shape of the **infant (pediatric) larynx**. In infants, the narrowest part is not the glottis, but the **subglottis** at the level of the cricoid cartilage. The larynx tapers downwards, creating a funnel shape. This is clinically significant because even minimal edema in this narrow subglottic region can cause significant airway obstruction (stridor) in children. * **Inverted funnel shape (Option C):** This is a distractor and does not describe the standard anatomical configuration of the larynx at any developmental stage. **High-Yield Clinical Pearls for NEET-PG:** * **Narrowest part (Adult):** Rima Glottidis (Glottis). * **Narrowest part (Infant):** Subglottis (at the level of the Cricoid cartilage). * **Position:** The adult larynx lies opposite **C3–C6** vertebrae, whereas the infant larynx is higher, situated opposite **C2–C4**. * **Epiglottis shape:** In infants, the epiglottis is often **Omega-shaped (Ω)** and more flaccid, which can contribute to laryngomalacia.

Q: Which are the blind areas of the larynx when visualized through video laryngoscopy?

Ventricle. The larynx contains several "hidden" or "blind" areas that are difficult to visualize completely using standard indirect laryngoscopy or fiberoptic video laryngoscopy. ### **Explanation of the Correct Answer** **A. Ventricle:** The laryngeal ventricle (Sinus of Morgagni) is a fusiform recess situated between the true vocal folds below and the false vocal folds (vestibular folds) above. Because it extends laterally and superiorly into the **saccule**, its interior depth cannot be visualized directly by looking down from above. It remains the most significant "blind spot" where early malignancies can remain occult. ### **Analysis of Incorrect Options** * **B. Subglottis:** While the subglottis is below the cords, it can often be partially visualized during deep inspiration when the cords abduct widely. It is considered a difficult area, but not a "blind" area in the same anatomical sense as the lateral recesses of the ventricle. * **C. Post-cricoid region:** This area lies behind the larynx (anterior wall of the hypopharynx). While it is a "hidden site" for malignancies, it is technically part of the **hypopharynx**, not the internal larynx. It can be visualized by maneuvers like the Valsalva or by tilting the scope. * **D. Lingual surface of epiglottis:** This is easily visualized as the scope passes over the base of the tongue into the vallecula. ### **High-Yield Clinical Pearls for NEET-PG** * **Hidden Sites of Larynx/Pharynx:** These include the **Ventricle**, **Subglottis**, **Post-cricoid space**, **Pyriform sinus apex**, and the **Posterior surface of the epiglottis**. * **Microlaryngoscopy (MLS):** This is the gold standard for evaluating these blind areas. To see the ventricle specifically, a probe is used to retract the false cords. * **Cancer Correlation:** Tumors arising in the ventricle (marginal tumors) often present late because they are shielded from view and do not cause early hoarseness.

Q: Which of the following describes a 'Scabbard Trachea'?

All of the above. ### Explanation **Scabbard Trachea** refers to a specific type of tracheal deformity where the airway becomes narrow and elongated in the anteroposterior diameter due to external pressure. **Why "All of the above" is correct:** * **Flattening of the trachea (Option A):** Chronic external pressure leads to the softening of the tracheal rings (tracheomalacia) and subsequent side-to-side narrowing. This results in a "flattened" appearance where the lateral walls are pushed inward, making the trachea look like a sword's sheath (scabbard). * **Lateral compression by swellings and tumors (Options B & C):** The most common cause is a **long-standing multinodular goiter** or a large thyroid malignancy. Any significant lateral mass, whether a benign swelling or a malignant tumor, that exerts persistent pressure on the flexible tracheal cartilages can result in this deformity. **Clinical Pearls for NEET-PG:** 1. **Most Common Cause:** Long-standing retrosternal or multinodular goiter. 2. **Radiological Finding:** On a chest X-ray or CT scan, the trachea appears narrowed in the coronal plane but elongated in the sagittal plane. 3. **Surgical Significance:** Patients with scabbard trachea are at high risk for **tracheal collapse** post-thyroidectomy. Once the supporting thyroid mass is removed, the weakened tracheal walls may collapse, leading to acute airway obstruction (requiring immediate intubation or tracheostomy). 4. **Diagnosis:** It is best evaluated using a CT scan of the neck and thorax to assess the degree of narrowing and the status of the cartilage.

Question 1

What is the commonest cause of hoarseness of voice in an elderly man with a duration of more than 3 months?

Accepted Answer

Cancer of the larynx

Answer

Chronic bronchitis

Answer

Acute laryngitis

Answer

Nodular goitre

Question 2

Which of the following is FALSE regarding laryngeal papillomatosis?

Accepted Answer

If it leads to respiratory distress, tracheotomy is done as an immediate procedure.

Answer

It is due to HPV infection.

Answer

Microdebrider is used for excision.

Answer

It has a high recurrence rate.

Question 3

Hoarseness with a typical barking cough and biphasic stridor are features of a lesion in which anatomical site?

Accepted Answer

Larynx

Answer

Hypopharynx

Answer

Trachea

Answer

Pharynx

Question 4

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

Accepted Answer

Bronchogenic cancer

Answer

Thyroid cancer

Answer

Thyroid surgery

Answer

Aortic aneurysm

Question 5

Bovine cough is characteristic of which of the following conditions?

Accepted Answer

Laryngeal paralysis

Answer

Acute epiglottitis

Answer

Foreign body aspiration

Answer

Chronic bronchitis

Question 6

Laryngocele arises from which anatomical structure?

Accepted Answer

Saccule of the ventricle

Answer

True vocal cords

Answer

Subglottis

Answer

Anterior commissure

Question 7

What is the anterior-posterior diameter of the vocal cords in adult males and females?

Accepted Answer

23 mm and 17 mm

Answer

24 mm and 36 mm

Answer

36 mm and 48 mm

Answer

48 mm and 36 mm

Question 8

What is the shape of the adult larynx?

Accepted Answer

Cylindrical

Answer

Funnel shaped

Answer

Inverted funnel shape

Answer

None of the above

Question 9

Which are the blind areas of the larynx when visualized through video laryngoscopy?

Accepted Answer

Ventricle

Answer

Subglottis

Answer

Post cricoid region

Answer

Lingual surface of epiglottis

Question 10

Which of the following describes a 'Scabbard Trachea'?

Accepted Answer

All of the above

Answer

Flattening of the trachea

Answer

Caused by lateral compression by swellings

Answer

Caused by lateral compression by tumors

Diseases of the Larynx — MCQs

Diseases of the Larynx — MCQs

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