Cancer detection after a 9-year course of Lambert-Eaton myasthenic syndrome complicated by anti-Hu associated limbic encephalitis

Neuromuscul Disord. 2023 Sep;33(9):90-92. doi: 10.1016/j.nmd.2023.06.011. Epub 2023 Jun 30.

Abstract

Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune neuromuscular junction disorder, paraneoplastic in 55% of cases and commonly associated with small-cell lung cancer (SCLC). We report the case of a 61-year-old man presented who with a 3-month history of lower limb proximal weakness, progressing to upper limbs, associated with dysphagia, xerostomia and erectile dysfunction. Electrodiagnostic studies and anti voltage-gated calcium channel (VGCC) antibodies (Abs) detection confirmed LEMS diagnosis. Contrast-enhanced thorax computed tomography (CT) scan and subsequently [18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) showed no malignancy. Two years after the onset of LEMS, he was diagnosed with anti-Hu limbic encephalitis (LE). FDG-PET/CT scan remained negative for the following seven years. Nine years after LEMS onset, a hypermetabolic lesion of the left lung hilus was detected. This is a case of a paraneoplastic LEMS where the interval between the onset of neurological disease and tumour detection was as long as nine years.

Keywords: Autoimmune encephalitis; Lambert-Eaton myasthenic syndrome; Paraneoplastic syndromes.

Publication types

  • Case Reports

MeSH terms

  • Autoantibodies
  • Calcium Channels
  • Fluorodeoxyglucose F18
  • Humans
  • Lambert-Eaton Myasthenic Syndrome* / complications
  • Lambert-Eaton Myasthenic Syndrome* / diagnosis
  • Limbic Encephalitis* / complications
  • Limbic Encephalitis* / diagnosis
  • Male
  • Middle Aged
  • Positron Emission Tomography Computed Tomography / adverse effects

Substances

  • Fluorodeoxyglucose F18
  • Autoantibodies
  • Calcium Channels