Meningiomas: Causes

Pathogenesis (development of disease)

Meningiomas arise from the covering cells of the arachnoid mater (spider web membrane; middle, soft meninges). Why the cells of the arachnoid degenerate has not yet been determined (spontaneous mutations).

Meningiomas are located close to the midline, often on the sphenoid wing (falx cerebri). They are usually well demarcated as well as encapsulated and attach to the dura mater (outermost and thickest layer of the meninges; it is directly adjacent to the skull). Meningiomas are hypervascularized, meaning they have more blood supply than tissues normally do. Tumor growth compresses adjacent brain tissue.Meningiomas may calcify (calcify). Rarely, a meningioma infiltrates the dura mater (hard meninges) or the skull bone.

Etiology (causes)

Biographic causes

  • Genetic burden from parents, grandparents
    • Genetic risk depending on gene polymorphisms
      • Genes/SNPs (single nucleotide polymorphism; single nucleotide polymorphism):
        • Genes: BRIP1, MILLT10, MTRR.
        • SNP: rs4968451 in the gene BRIP1
          • Allele constellation: AC (1.61-fold).
          • Allele constellation: CC (2.33-fold)
        • SNP: rs11012732 in the gene MILLT10
          • Allele constellation: AG (1.4-fold).
          • Allele constellation: GG (2.0-fold)
        • SNP: rs1801394 in the gene MTRR
          • Allele constellation: GG (1.4-fold).
    • Genetic disorders (associated with meningiomas).
      • Monosomy 22 – chromosome 22 is present only once.
      • Neurofibromatosis type 2 – genetic disease with autosomal dominant inheritance; belongs to the phakomatoses (diseases of the skin and nervous system); characteristic are an acoustic neuroma (vestibular schwannoma) present bilaterally (on both sides) and multiple meningiomas (meningeal tumors)

Behavioral causes

  • Being overweight (BMI ≥ 25; obesity) – higher likelihood of developing meningioma:
    • BMI 25-29.9: 21%
    • BMI ≥ 30: 54

Medication

Radiotherapy