Merkel cell carcinoma (MCC), a rare but aggressive primary cutaneous neuroendocrine tumour, is associated with which viral oncogen and immunosuppressed state?
- A Merkel cell polyomavirus (MCPyV) large T-antigen integration ✓
- B HPV-16/18 E6/E7 oncoproteins
- C EBV LMP-1 driving B-cell transformation
- D HHV-8 KSHV ORF72 cyclin
Correct answer: A. Merkel cell polyomavirus (MCPyV) large T-antigen integration
Explanation
Merkel cell carcinoma integrates the Merkel cell polyomavirus (MCPyV) genome in ~80% of tumours. The viral large T-antigen undergoes truncating mutations after integration that retain Rb-inactivating capacity but lose replication ability, driving clonal tumour expansion. MCPyV integration is the molecular hallmark. MCC is more common in immunosuppressed patients (solid organ transplant, CLL, HIV). KSHV causes KS; EBV causes certain lymphomas.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.