Canis ISSN: 2398-2942

Suprasellar germ cell tumor

Synonym(s): Intracranial germ cell tumor, germinoma, embryonal carcinoma, tetratoma, malignant germ cell tumor

Contributor(s): Kyle Braund

Introduction

  • Rare brain neoplasia.
  • Signs: insidious onset and protracted course suggestive of a focal space-occupying lesion, eg:
    • Visual disturbance.
    • Pupil abnormality.
    • Lethargy and anorexia.
    • Depression.
    • Abnormal posture/movements.
  • Diagnosis: signs, CT, MRI.
  • Treatment: surgery, palliative radiotherapy and/or steroids.
  • Prognosis: grave.

Pathogenesis

Predisposing factors

General
  • Presently undetermined.

Specific

  • Presently undetermined.

Pathophysiology

  • Germ cell tumors arise as the result of neoplastic changes that occur during embryonic development.
  • These germinal cells migrate from the yolk sac during early embryonic life.
  • Germ cell tumors in dog most commonly develop in the suprasellar region (to date, no tumor has involved the pineal gland).
  • Tumor growth → compression and/or infiltration of surrounding structure:
    • Diencephalon → lethargy/depression, abnormal posture/movements, brachycardia.
    • Optic chiasm/optic tract/oculomotor nerves → visual impairment, dilated pupils, loss of pupillary light reflexes and ptosis.
    • Other cranial nerves (V, VI, VII) → jaw paralysis, attenuated eye movements, facial paralysis.
    • Pituitary gland → polydipsia, polyaria and polyphagia; hypothyroidism, panhypopituitarism (note - signs of pituitary dysfunction are uncommon).

Timecourse

  • Usually slowly progressive course (weeks to several months).

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.
  • Hare W R (1993) Primary suprasellar germ cell tumor in a dog. JAVMA 203 (10), 1432-1433 PubMed.
  • Nyska A et al (1993) Suprasellar differentiated germ cell tumor in a male dog. J Vet Diag Invest (3), 462-467 PubMed.
  • Summers B A et al (1989) Intracranial germ cell tumors in two dogs. JSAP 30 (1), 39-42 VetMedResource.
  • Valentine B A et al (1988) Suprasellar germ cell tumors in the dog - a report of five cases and review of the literature. Acta Neuropathol 76 (1), 94-100 PubMed.


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