A 52-year-old man presents with a persistently enlarged right tonsil and a right level II lymph node. Biopsy of the tonsil shows non-keratinising squamous cell carcinoma. Immunohistochemistry for p16 is strongly positive. The infectious agent implicated in this tumour subtype is:
- A Human papillomavirus type 16 ✓
- B Epstein-Barr virus
- C Hepatitis C virus
- D Herpes simplex virus type 1
Correct answer: A. Human papillomavirus type 16
Explanation
Oropharyngeal squamous cell carcinoma arising in the tonsil and base of tongue is strongly associated with high-risk human papillomavirus, especially type 16, and shows p16 overexpression on immunohistochemistry. HPV-positive oropharyngeal cancers have a better response to treatment than HPV-negative ones. Epstein-Barr virus is the oncogenic driver in nasopharyngeal carcinoma, a distinct anatomical site, and is the distractor here because both viruses cause head and neck malignancy.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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