[Pembrolizumab-associated autoimmune encephalitis in an elderly patient with advanced non-small cell lung cancer. A clinical case].

Therapeutic objectives for the geriatric patient are improvement of quality of life and functional capacity rather than a mere increase in survival. In neoplastic disease, the decision to initiate administration of curative therapies, especially immunotherapy, should be taken only after any potential risks have been taken into account. Geriatric patients are more susceptible to developing more serious adverse reactions than the younger population. We report the case of an octogenarian patient with non-small cell lung cancer who developed neurologic toxicity following pembroli-zumab therapy. We carry out a differential diagnosis of encephalitis and provide a literature review of pembrolizumab-associated auto-immune encephalitis cases in order to improve our knowledge of this unusual toxicity. An interdisciplinary approach and comprehensive geriatric assessment are essential components to prevent functional decline in the elderly.