TB larynx most commonly affect:
**Core Concept**
TB larynx is a rare form of extrapulmonary tuberculosis that affects the larynx, often presenting with hoarseness, pain, or difficulty swallowing. The pathogenesis involves the hematogenous spread of Mycobacterium tuberculosis to the larynx, where it causes granulomatous inflammation and tissue damage.
**Why the Correct Answer is Right**
The correct answer is the part of the larynx most commonly affected by TB larynx. The anterior commissure is a common site due to its rich blood supply and high oxygen tension, making it a favorable environment for the growth of M. tuberculosis. The granulomatous inflammation and subsequent scarring can lead to vocal cord fixation and impairment of voice quality.
**Why Each Wrong Option is Incorrect**
**Option A:** The vocal process of the arytenoid cartilage is not a common site for TB larynx, as it is less vascularized compared to the anterior commissure.
**Option B:** The posterior commissure is not typically affected by TB larynx, as it is less exposed to the hematogenous spread of M. tuberculosis.
**Option C:** The epiglottis is not a common site for TB larynx, as it is not typically involved in the hematogenous spread of the disease.
**Clinical Pearl / High-Yield Fact**
TB larynx can present with a range of symptoms, including hoarseness, pain, or difficulty swallowing, and can be challenging to diagnose due to its rarity. A high index of suspicion and careful examination of the larynx are essential for early diagnosis and treatment.
**Correct Answer:** C.