A Neuropsychiatric Prelude to Unveiling Small Cell Lung Cancer with Suspected Paraneoplastic Limbic Encephalitis: A Case Report

This is the authors' abstract. We don't add key points for this paper.

Small cell lung cancer (SCLC) is an aggressive form of lung cancer characterized by rapid growth and early metastases. As a neuroendocrine tumour, SCLC is especially notorious for various paraneoplastic syndromes, one of which is a rare neurological syndrome called paraneoplastic limbic encephalitis (PLE) that manifests with amnestic cognitive impairment and seizures. Here, we describe a case of a 53-year-old female who presented with neuropsychiatric symptoms of delusions, hallucinations, and cognitive impairment that started months prior to being diagnosed with extensive-stage SCLC. With no previous neuropsychiatric history, this raised the question of whether her presentation was related to PLE rather than a primary psychiatric condition, as initially diagnosed. Her symptoms improved with chemotherapy and radiation treatment of the underlying cancer, favouring a paraneoplastic etiology. Overall, this case underscores the importance of considering paraneoplastic syndromes in patients presenting with new neuropsychiatric symptoms, as early recognition and treatment can improve prognosis.