Central Nervous System Tumors - CNS Tumors

Central Nervous System Tumors - CNS Tumors

 

Central nervous system tumors cause either focal or generalized neurologic symptoms.

Epidemiology

  • Incidence – ~41,000 new cases of primary brain tumors are diagnosed yearly in the U.S.
    • Half are histologically benign
  • Gender – F slightly >M
    • Higher meningioma incidence in females

Risk factors

  • Ionizing radiation (gliomas)
  • Familial
    • Neurofibromatosis 1 (NF-1), (neurofibroma, glioma, sarcoma)
    • Neurofibromatosis 2 (NF-2a), Schwannoma glioma, meningioma
    • Tuberous sclerosis (astrocytoma)
    • Von Hippel-Lindau (hemangioblastoma)
    • Li Fraumeni (glioma)
    • Retinoblastoma
    • Multiple endocrine neoplasia 1 (pituitary adenoma, Schwannoma glioma)
  • Virus infection
    • HIV infection is associated with an increased risk of CNS lymphoma

Pathophysiology

  • Histologically classified as glioma or nonglioma
    • Gliomas
      • Astrocytomas (includes glioblastoma multiforme)
      • Oligodendrogliomas
      • Mixed gliomas
      • Ependymomas
    • Nongliomas
      • Meningiomas – usually benign
      • Pituitary adenomas – often benign
      • Primary CNS lymphoma
      • Medulloblastoma – childhood cerebellar tumor
      • Brain metastases – lung, breast and melanoma are most common
  • Malignant gliomas are the most common type of primary brain tumor
  • Separation of astrocytomas from oligodendrogliomas has prognostic and therapeutic importance

Clinical Presentation

  • Headache, nausea, vomiting, hemiparesis, aphasia
  • Seizures – more common with gliomas

Diagnosis

  • Laboratory testing
    • Very few abnormalities except for increased erythrocyte sedimentation rate (ESR)
  • Imaging studies
    • CT, MRI, PET
  • Markers
    • Combined loss of short arm of chromosome 1 (1p) and long arm of chromosomes 19 (19q) is considered a diagnostic and prognostic marker of oligodendrogliomas
      • Patients with 1p and 19q deletions have a better prognosis than those without the deletions
      • Loss of 1p may identify treatment-sensitive malignant gliomas, in particular, subtypes of anaplastic oligodendroglioma

See Also