[Paraneoplastic limbic encephalitis and epidermoid carcinoma of the pyriform]

Paraneoplastic limbic encephalitis is a syndrome characterised by behaviour changes, short-term memory loss and seizures. We report on a case of a 62-year-old man, ex-smoker who was admitted to the Intensive Care Unit with seizures, and who had previously experienced behaviour changes. Tests revealed nothing notable, except for the CSF examination which revealed elevated protein and MRI findings indicating temporal lobe abnormalities. Once other diagnoses had been ruled out, neoplasm screening was initiated. Conventional imaging failed to identify the tumour. Antineuronal anti-Hu antibodies were negative. Finally, fluorodeoxyglucose (FDG) whole body -PET imaging was carried out revealing a pathologically increased glucose metabolism at the pharynx-larynx level. The biopsy showed an epidermoid carcinoma of the pyriform sinus. To the best of our knowledge, this is the first reported case of an epidermoid carcinoma of the pyriform sinus associated with paraneoplastic limbic encephalitis.