Keywords: AIDS; CR, complete response; HIV; ICI, immune checkpoint inhibitors; IHC, immunohistochemistry; MCC; MCC, Merkel cell carcinoma; MCPyV, Merkel cell polyomavirus; Merkel cell carcinoma; PD-1, anti-programmed cell death-1; PD-L1, anti-programmed death ligand-1; PET, positron emission tomography; RT, radiation treatment; aMCC, advanced Merkel cell carcinoma; anti-PD-(L)1 agent; immunotherapy.