Steroid refractory immune-related acute disseminated encephalomyelitis (ADEM) successfully treated with 2nd and 3rd line immunosuppressive therapy

We describe immune-related acute disseminated encephalomyelitis (ADEM) in a woman in her 60s. This was her third immune-related adverse event (IRAE) secondary to immunotherapy treatment for metastatic melanoma. Initially thought to be intracranial metastatic disease, the diagnosis was reconsidered due to atypical radiological findings. With the persistence and open-minded approach of the wider multidisciplinary team (MDT), a definitive diagnosis of ADEM was reached. Refractory to the conventional management of IRAEs with corticosteroids, the patient was successfully treated with intravenous immunoglobulins (IVIG), followed by tocilizumab and mycophenolate mofetil (MMF), ultimately resulting in complete radiological resolution of ADEM. This case highlights the importance of early suspicion, identification and management of IRAEs when oncology patients present acutely.