Which is the most common site of origin of laryngeal carcinoma?

Explanation

## Laryngeal Carcinoma — Site of Origin **Key Point:** The true vocal cord (glottic region) is the most common site of origin of laryngeal squamous cell carcinoma, accounting for approximately 60–70% of all laryngeal cancers. ### Why the Glottic Region? 1. **Prolonged Exposure to Carcinogens:** The true vocal cords are in direct contact with tobacco smoke and alcohol vapors during phonation. 2. **Thin Epithelium:** The stratified squamous epithelium of the vocal cords is relatively thin and lacks a protective mucous layer, increasing carcinogen penetration. 3. **Pooling of Secretions:** Secretions tend to pool along the vocal cords, prolonging carcinogen contact time. 4. **Early Symptom Detection:** Hoarseness develops early due to vocal cord involvement, leading to earlier diagnosis and better prognosis compared to supraglottic cancers. ### Laryngeal Cancer Distribution by Site | Site | Frequency | Prognosis | Stage at Diagnosis | |------|-----------|-----------|-------------------| | Glottic (true vocal cord) | 60–70% | Best (5-yr ~80%) | Early (I–II) | | Supraglottic | 25–35% | Intermediate (5-yr ~50%) | Advanced (III–IV) | | Subglottic | 5–10% | Poor (5-yr ~30%) | Advanced | | Transglottic | Rare | Poor | Advanced | ### Clinical Pearl **Glottic cancers have the best prognosis** because: - Early hoarseness prompts medical evaluation - Limited lymphatic drainage → lower nodal metastasis rate - Amenable to voice-preserving treatment (radiation, laser microsurgery) **High-Yield:** Any patient with persistent hoarseness >2 weeks requires laryngoscopy to rule out glottic malignancy. This is a **NEET PG high-yield fact**. ### Supraglottic vs. Glottic — Key Contrast | Feature | Glottic | Supraglottic | |---------|---------|-------------| | Early symptom | Hoarseness | Throat pain, dysphagia | | Lymph node involvement | 10–15% | 40–50% | | Stage at diagnosis | I–II (early) | III–IV (advanced) | | 5-year survival | ~80% | ~50% | [cite:Cummings Otolaryngology 6e Ch 89]