Optic neuritis induced by Pembrolizumab treatment for recurrent vulvar cancer

To describe a novel case of optic neuritis induced after pembrolizumab treatment for recurrent vulvar cancer. Immunotherapy is becoming increasingly important as a therapy for cases of vulvar cancer that are resistant to standard treatment. A 53-year-old female with a history of recurrent vulvar cancer presented with sudden-onset progressive vision loss in both eyes for four weeks. Initially patient was thought to have brain metastases based on imaging, but after a thorough workup, the diagnosis of optic neuritis was made. Pembrolizumab therapy was immediately ceased, and high-dose corticosteroids were used to treat the patient effectively and reverse her symptoms. Several cases of CNS toxicity and optic neuritis have been reported with the use of pembrolizumab immunotherapy but, to our knowledge, this is the first reported case to have occurred in the setting of recurrent vulvar cancer. In these cases it is important to have prompt discontinuation of the offending agent and treatment with high-dose corticosteroid course.