Canis ISSN: 2398-2942

Brain: ependymoma

Synonym(s): Medulloblastoma, neuroblastoma, brain neoplasia

Contributor(s): Laurent Garosi

Introduction

  • Rare tumor (<2% of neuroglial tumors), more frequent in brachycephalic breeds.
  • May cause acquired hydrocephalus.
  • Signs: as in space-occupying lesions in the brain. Additional signs due to obstructive hydrocephalus and uncompensated intracranial hypertension.
  • Diagnosis: signs, MRI, definitive diagnosis only by biopsy (often post-mortem).
  • Treatment: symptomatic, radiotherapy, ventriculoperitoneal shunting.
  • Prognosis: tend to invade the ventricular system, commonly metastasize in the cerebrospinal fluid (CSF) system.

Pathogenesis

Etiology

  • Neoplasm of the lining epithelium of the ventricles and spinal cord central canal.

Predisposing factors

General
  • Presently unknown.

Specific

  • Presently unknown.

Pathophysiology

  • Ependymomas are histologically benign neoplasms which arise from the epithelial lining of the ventricles and spinal cord central canal.
  • These tumors have a propensity to penetrate brain parenchyma and may invade the ventricular system and meninges by exfoliation of neoplastic cells and drop metastasis in cerebrospinal pathways.
  • Malignant transformation is rare. Because of their ventricular orientation ependymomas have a tendency to obstruct cerebrospinal pathways, particularly when thay arise in the fourth ventricle. The resultant is obstructive hydrocephalus.
  • They occur most commonly in lateral/third ventricles.
  • Space-occupying lesion → local brain compression and zone of edema around tumor → focal interference with brain function → tumor growth → progressive focal neurological deficits; often occurs in the ventricular system → acquired obstructive hydrocephalus.

Timecourse

  • Insidious onset.

Diagnosis

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Treatment

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Dickinson P J (2014) Advances in diagnostic and treatment modalities for intracranial tumors. JVIM 28, 1165-1185 PubMed.
  • Rossmeisl J H Jr, Jones J C, Zimmerman K L et al (2013) Survival time following hospital discharge in dogs with palliatively treated primary brain tumors. JAVMA 242, 193-198 PubMed.
  • Rodenas S, Pumarola M, Gaitero L et al (2011) Magnetic resonace imageing findings in 40 dogs with histologically confirmed intracranial tumours. Vet J 187, 218-225 PubMed.
  • Synder J M, Shofer F S, Van Winkle K A (2008) Canine intracranial primary neoplasia: 173 cases (1986-2003). JVIM 22, 172-177 PubMed.
  • Thomas W T, Wheeler S J et al (1996) MRI features of primary brain tumors in dogs. Vet Radiol Ultrasound 37 (1), 20-27 Wiley Online Library.
  • Keller E T & Madewell B R (1992) Locations and types of neoplasms in immature dogs - 69 cases (1964-1989). JAVMA 200 (10), 1530-1532 PubMed.
  • Heidner G L, Kornegay J N, Page R L et al (1991) Radiotherapy of brain tumors in dogs. J Vet Intern Med (4), 219-226 Wiley Online Library.
  • Bailey C S & Higgins R J (1986) Characteristics of cisternal CSF associated with primary brain tumors in the dog. A retrospective study. JAMVA 188 (4), 414-417 PubMed.
  • Turrel J M et al (1986) Computed tomographic characteristics of primary brain tumors in 50 dogs. JAVMA 188 (8), 851-856 PubMed.
  • Vandervelde M et al (1985) Immunocytochemical studies in canine neuroectodermal brain tumours. Acta Neuropathol 66 (2), 111-116 PubMed.

Other sources of information

  • Braund K G (1994)Clinical syndromes in veterinary neurology.2nd edn. St. Louis: Mosby Year Book. pp 198-207.
  • Braund K G & Rebas J L (1985)Brain ventricular tumors.ACVIM Proceedings, 3rd Annual Forum, San Diego, June 1-4. pp 157-158.


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