Nasopharyngeal carcinoma (NPC) is strongly associated with EBV. Which histological subtype of NPC (WHO classification) is MOST common globally and has the BEST prognosis?
- A WHO Type 1 (Keratinizing squamous cell carcinoma) — most common globally, worst prognosis
- B WHO Type 3 (Non-keratinizing undifferentiated/lymphoepithelioma) — most common in endemic areas, most radiosensitive, best overall prognosis in endemic populations ✓
- C WHO Type 2 (Non-keratinizing differentiated carcinoma)
- D WHO Type 1 keratinizing — most common in endemic areas, best prognosis
Correct answer: B. WHO Type 3 (Non-keratinizing undifferentiated/lymphoepithelioma) — most common in endemic areas, most radiosensitive, best overall prognosis in endemic populations
Explanation
WHO Type 3 NPC (undifferentiated/lymphoepithelioma) is the predominant subtype in EBV-endemic regions (Southeast Asia, North Africa). It is highly radiosensitive and immunogenic (dense lymphocytic infiltrate), resulting in better response to chemoradiotherapy and improved overall survival compared to Type 1. WHO Type 1 (keratinizing SCC) is more common in non-endemic regions, less strongly EBV-associated, and has the worst prognosis due to reduced radiosensitivity and less immune infiltration.
Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.