Paraneoplastic limbic encephalitis

Case contributed by A.Prof Frank Gaillard


New onset seizures.

Patient Data

Age: 70 years

MRI Brain

The hippocampal head and the medulla, and to a lesser degree, hippocampal body on the right demonstrate increased T2 signal and appear bulkier than the counterpart on the left. There is increased DWI signal, without convincing facilitated diffusion on ADC; some areas demonstrate slight reduction in ADC values. There is apparent faint enhancement within the inferior amygdala only seen on coronal images which is not categorically a real finding.

MR perfusion appears symmetric. MR spectroscopy is noncontributory.


Swelling increased T2 signal of the right hippocampus and amygdala has a differential of infiltrating tumor and limbic encephalitis (e.g. paraneoplastic). Limited, if any, change over the previous two weeks both on imaging and clinical status, makes herpes encephalitis very unlikely. The changes are too pronounced to represent post-seizure effects.

Heterogenous enhancing right adnexal mass is present.

Hypodense 1 cm lesion at the dome of segment 7 of the liver is incompletely characterized but possibly represent a hepatic cyst. No other focal liver lesion.

The spleen, adrenals, kidneys, pancreas, gallbladder, urinary bladder, uterus and left ovary are within normal limits.

No lymphadenopathy or free fluid. 

Case Discussion


MICROSCOPIC DESCRIPTION: The smear contains scattered lymphocytes, few monocytes and degenerate cells. No malignant cells are identified.

DIFFERENTIAL CELL COUNT of 0.5 ml Lymphocytes 35 Monocytes 8 Neutrophils 0 Eosinophils 0 DIAGNOSIS: Cerebrospinal fluid: Mild chronic inflammation.

Antibodies and tumor markers

  • CA-125-New 16 U/mL (normal <35)
  • CA19.9-New 10 U/ml (normal <37)
  • Serum/Plasma CEA-New 2.7 ug/L (normal <5.0)
  • ISLET CELL ANTIBODIES - Serum/Plasma GAD (EIA) <0.6 U/mL (normal <5)
  • GABA-B Receptor Antibodies: NOT DETECTED
  • AMPA Receptor Antibodies: NOT DETECTED
  • NMDA Receptor Antibodies: Not Detected
  • Anti VGKC Antibody 9 pmol/L (normal <85 )
  • Anti-Hu (ANNA-1) antibodies POSITIVE.

Anti-Hu antibodies are detected in paraneoplastic peripheral neuropathy or encephalomyelitis, usually in the setting of small cell lung carcinoma, although many other primaries have been described including the ovary 1


In this case, the imaging appearances and presence of a pelvic mass are compelling for the diagnosis of paraneoplastic encephalomyelitis

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Case information

rID: 49593
Published: 15th Dec 2016
Last edited: 22nd Sep 2019
Inclusion in quiz mode: Included

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