Abstract
A 42-year-old man was referred to psychiatry with acute onset of confusion and agitation. His screening computed tomography scan showed middle mediastinal tumours. Preoperative cerebrospinal fluid analysis was positive for anti-contactin-associated protein-like 2 antibody; possible paraneoplastic limbic encephalitis was diagnosed. Tumour resection was performed. Pathological examination showed thymic neuroendocrine tumour, stage IV. Postoperatively, the patient was treated with everolimus for adjuvant therapy, with complete improvement of encephalitis symptoms. The patient remained well without tumour recurrence or exacerbation of psychiatric disorders for 14 months after the operation.