Merkel cell polyomavirus-positive Merkel cell carcinoma in a patient with epidermodysplasia verruciformis.

Epidermodysplasia verruciformis (EV) is a rare auto­ somal recessive disease characterised by abnormal susceptibility to disease-specific human papillomaviruses (HPVs), possibly due to suppressed cellular innate im­ munity. EVER1/TMC6 or EVER2/TMC8 gene mutations are often found in EV (1). All patients with EV usually have similar skin lesions from their childhood, involving disseminated flat warts or pityriasis versicolor. Elderly patients with EV have a high risk of developing carcino­ mas in situ and invasive squamous cell carcinoma (SCC) associated with HPV infections, mainly on sun­exposed skin. On the other hand, Merkel cell polyomavirus (MC­ PyV) is detected in most Merkel cell carcinomas (MCC) (2), which arise from Merkel cells, neuroendocrine cells in the skin. We present here a rare occurrence of MCPyV+ MCC in a patient with EV.