A 45-year-old renal transplant recipient on tacrolimus, mycophenolate mofetil, and prednisolone develops an enlarging perianal lesion. Biopsy shows squamous cell carcinoma. Which causative agent is most strongly associated with this complication of immunosuppression?

• A Epstein-Barr virus (EBV)
• B Cytomegalovirus (CMV)
• C Human herpesvirus 8 (HHV-8)
• D Human papillomavirus (HPV) — high-risk strains 16 and 18 ✓

Explanation

Immunosuppressed transplant recipients have a markedly elevated risk of HPV-related squamous cell carcinomas, particularly of the anogenital region (anal, vulval, penile, cervical). High-risk HPV strains (16 and 18) integrate into host DNA, inactivating p53 and Rb tumour suppressors. The normally competent immune response that controls persistent HPV infection is ablated by tacrolimus and mycophenolate. EBV causes post-transplant lymphoproliferative disorder (PTLD); HHV-8 causes Kaposi's sarcoma in transplant recipients.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.