Paraneoplastic Limbic Encephalitis Preceding the Diagnosis of Small Cell Lung Carcinoma: A Review of Published Cases
DOI:
https://doi.org/10.5281/zenodo.22279500Keywords:
Paraneoplastic limbic encephalitis, Small cell lung carcinoma, Anti-Hu antibody, Autoimmune encephalitis, Paraneoplastic neurological syndromeAbstract
Background: Paraneoplastic limbic encephalitis (PLE) is an immune-mediated syndrome of subacute memory loss, seizures and
psychiatric change that often precedes recognition of its underlying malignancy, most commonly small cell lung carcinoma
(SCLC). Objective: To review published cohorts, series and case reports of PLE preceding SCLC diagnosis, summarising epidemiology,
pathophysiology, presentation, diagnosis, management and outcome. Methods: Narrative review of case reports, series, cohorts and diagnostic-criteria literature. Findings: Neurological onset preceded cancer diagnosis in 60% of PLE patients (median 3.5 months) in one landmark series, and in 71% of anti-Hu encephalomyelitis patients in another. Published cases show intervals from days to months, antibody status spanning anti-Hu, anti-GABA-B receptor, anti-amphiphysin and seronegative disease, and FDG-PET detecting the tumour in 70-90% of cases when conventional imaging is negative. Neurological improvement, seen in under half of patients overall, is
strongly linked to complete tumour response. Conclusions: PLE should prompt urgent SCLC screening even with normal imaging, since oncological treatment remains the dominant modifiable outcome determinant.
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