Persistent erythema multiforme in a patient with extrahepatic cholangiocarcinoma.

Presented in this report is a 66-year-old male with a widespread persistent erythema multiforme mostly atypical in appearance, which was detected well before the diagnosis of underlying extrahepatic cholangiocarcinoma. The lesions regressed in response to chemotherapy, but they appeared again in connection with tumor relapse. Clinicians should recognize persistent erythema multiforme as one of the paraneoplastic dermatoses and efforts should be made to detect internal malignancies in patients with these skin lesions.