Squamous Cell Lung Carcinoma Presenting With Refractory Status Epilepticus: A Case Report of Paraneoplastic Limbic Encephalitis

Abstract

Lung cancer-associated paraneoplastic syndromes affecting the central nervous system present significant diagnostic and treatment challenges. In this case, the patient presented with personality change, cognitive impairment, complex partial seizures, ataxia, dyspraxia, and dysphasia. Shortly after admission, the patient suffered refractory generalized tonic-clonic seizures and a decreased level of consciousness and required intubation, ventilation, and admission to the ICU. He was subsequently diagnosed with paraneoplastic limbic encephalitis based on recognized criteria, including a compatible clinical picture, elevated protein content in his cerebrospinal fluid with negative cytology, a positive positron emission tomography-computed tomography scan showing a right upper lobe tumor, and the exclusion of other neuro-oncological complications. Histopathology confirmed the tissue diagnosis as squamous cell cancer. Initial immunotherapy with steroids and intravenous immunoglobulin and subsequent lobectomy and adjuvant chemotherapy were partially successful, leading to partial resolution of his cognitive impairment. This report highlights the diagnostic and therapeutic challenges of lung-related paraneoplastic syndromes. In addition, it illustrates the poor outcomes for patients and identifies squamous cell cancer as an extremely rare cause of paraneoplastic limbic encephalitis.