December 2015

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december 2015

 

Animal: Dog, West Highland White Terrier, 8-years old, male

Diagnosis: Cerebrum, right hemisphere: oligodendroglioma with local invasion into the meninges, necrosis, multifocal hemorrhages and secondary hydrocephalus internus

Description: The cross section of the frontal lobe at the level of the basal nuclei revealed an irregularly bordered but well circumscribed, soft and gelatinous, grey to brownish mass of up to 1.5 cm in diameter extending from the frontal to the temporal lobe, partly invading the meninges. Within the mass, multifocal areas of hemorrhage and necrosis were present. Furthermore, the severely dilated lateral ventricles were filled with 60 ml of clear cerebrospinal fluid (liquor).

Comments: The dog was euthanized due to progressive neurological symptoms including epileptic seizures, apathy and vomitus.

In addition to the cerebral mass, necropsy revealed an adenoma of the nasal mucosa and an interstitial cell tumor of the testis. Histologically, the cerebral mass consisted of monomorphic, mostly densely packed cells with nuclear atypia and vacuolated, eosinophilic cytoplasm. A prominent microvascular proliferation, interstitial accumulation of myxoid matrix as well as extensive foci of necrosis and hemorrhage were also present.

Oligodendroglioma is one of the most commonly seen primary tumors of the cerebrum in dogs but also occurs in cattle, cats and horses. Its incidence is age-related and brachycephalic dogs are predisposed. Invasion into the ventricular system or the meninges is often seen in grade III tumors.

Picture and authored by: Kristina Dietert, Department of Veterinary Pathology, Freie Universität Berlin, Germany