Abstract
Currently, immune checkpoint inhibitors are used in the treatment of ovarian cancer. Immunotherapy agents occasionally cause the development of skin reactions characterized by mild erythematous and maculopapular rashes, usually involving the trunk and extremities of the body, which may occasionally present with pruritus. It is especially seen in the use of anti-PD-1 (nivolumab and pembrolizumab) treatment agents. In this case report, we present a patient who developed discoloration of the tongue toxicity after nivolumab treatment in ovarian cancer patients. Discoloration of the tongue, which is one of the rare side effects of immunotherapy, and factors that may be associated with it are discussed in this case.