Novel Histopathological Patterns in Cortical Tubers of Epilepsy Surgery Patients with Tuberous Sclerosis Complex

PLoS One. 2016 Jun 13;11(6):e0157396. doi: 10.1371/journal.pone.0157396. eCollection 2016.

Abstract

Tuberous Sclerosis Complex (TSC) is a genetic hamartoma syndrome frequently associated with severe intractable epilepsy. In some TSC patients epilepsy surgery is a promising treatment option provided that the epileptogenic zone can be precisely delineated. TSC brain lesions (cortical tubers) contain dysmorphic neurons, brightly eosinophilic giant cells and white matter alterations in various proportions. However, a histological classification system has not been established for tubers. Therefore, the aim of this study was to define distinct histological patterns within tubers based on semi-automated histological quantification and to find clinically significant correlations. In total, we studied 28 cortical tubers and seven samples of perituberal cortex from 28 TSC patients who had undergone epilepsy surgery. We assessed mammalian target of rapamycin complex 1 (mTORC1) activation, the numbers of giant cells, dysmorphic neurons, neurons, and oligodendrocytes, and calcification, gliosis, angiogenesis, inflammation, and myelin content. Three distinct histological profiles emerged based on the proportion of calcifications, dysmorphic neurons and giant cells designated types A, B, and C. In the latter two types we were able to subsequently associate them with specific features on presurgical MRI. Therefore, these histopathological patterns provide consistent criteria for improved definition of the clinico-pathological features of cortical tubers identified by MRI and provide a basis for further exploration of the functional and molecular features of cortical tubers in TSC.

MeSH terms

  • Adolescent
  • Adult
  • Cerebral Cortex / pathology*
  • Cerebral Cortex / surgery
  • Child
  • Child, Preschool
  • Epilepsy / complications*
  • Epilepsy / metabolism
  • Epilepsy / pathology*
  • Epilepsy / surgery
  • Female
  • Gliosis / complications
  • Gliosis / pathology
  • Humans
  • Male
  • Mechanistic Target of Rapamycin Complex 1
  • Middle Aged
  • Multiprotein Complexes / analysis
  • Multiprotein Complexes / metabolism
  • Myelin Sheath / metabolism
  • Myelin Sheath / pathology
  • Neurons / pathology
  • TOR Serine-Threonine Kinases / analysis
  • TOR Serine-Threonine Kinases / metabolism
  • Tuberous Sclerosis / complications*
  • Tuberous Sclerosis / metabolism
  • Tuberous Sclerosis / pathology*
  • Tuberous Sclerosis / surgery
  • Young Adult

Substances

  • Multiprotein Complexes
  • Mechanistic Target of Rapamycin Complex 1
  • TOR Serine-Threonine Kinases

Grants and funding

This work was supported by the Austrian Science Fund (FWF): project no. J3499 (AM), Czech Ministry of Health grant: IGA NT/11443-5 (PK), MH CZ – DRO nr. 00064203 (JZ) and by the Framework Programme FP7/2007-2013 under the project acronym EPISTOP (grant agreement no. 602391; JvS, AI, HH, TS, EA, FJ, MF, BB, PK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.