Mild Malformation of Cortical Development with Oligodendroglial Hyperplasia in Frontal Lobe Epilepsy: A New Clinico-Pathological Entity

Brain Pathol. 2017 Jan;27(1):26-35. doi: 10.1111/bpa.12347. Epub 2016 Feb 22.


The histopathological spectrum of human epileptogenic brain lesions is widespread including common and rare variants of cortical malformations. However, 2-26% of epilepsy surgery specimens are histopathologically classified as nonlesional. We hypothesized that these specimens include also new diagnostic entities, in particular when presurgical magnetic resonance imaging (MRI) can identify abnormal signal intensities within the anatomical region of seizure onset. In our series of 1381 en bloc resected epilepsy surgery brain specimens, 52 cases could not be histopathologically classified and were considered nonlesional (3.7%). An increase of Olig2-, and PDGFR-alpha-immunoreactive oligodendroglia was observed in white matter and deep cortical layers in 22 of these patients (42%). Increased proliferation activity as well as heterotopic neurons in white matter were additional histopathological hallmarks. All patients suffered from frontal lobe epilepsy (FLE) with a median age of epilepsy onset at 4 years and 16 years at epilepsy surgery. Presurgical MRI suggested focal cortical dysplasia (FCD) in all patients. We suggest to classify this characteristic histopathology pattern as "mild malformation of cortical development with oligodendroglial hyperplasia (MOGHE)." Further insights into pathomechanisms of MOGHE may help to bridge the diagnostic gap in children and young adults with difficult-to-treat FLE.

Keywords: epilepsy; frontal lobe; hyperplasia; neuropathology; oligodendrocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age of Onset
  • Cell Division
  • Child
  • Child, Preschool
  • Drug Resistant Epilepsy / diagnostic imaging
  • Drug Resistant Epilepsy / pathology
  • Drug Resistant Epilepsy / surgery
  • Epilepsy, Frontal Lobe / diagnostic imaging
  • Epilepsy, Frontal Lobe / pathology*
  • Epilepsy, Frontal Lobe / surgery
  • Female
  • Humans
  • Hyperplasia
  • In Situ Hybridization, Fluorescence
  • Magnetic Resonance Imaging
  • Male
  • Malformations of Cortical Development / diagnostic imaging
  • Malformations of Cortical Development / pathology*
  • Middle Aged
  • Neuroimaging
  • Oligodendrocyte Transcription Factor 2 / analysis
  • Oligodendroglia / pathology*
  • Young Adult


  • OLIG2 protein, human
  • Oligodendrocyte Transcription Factor 2