Case Study

CT – Intraaxial mass lesion in the right cerebral hemisphere, likely neoplasia, of a 10 year old FS Yorkshire Terrier dog

This 10 year old F Yorkshire Terrier has a history of seizures since 3-20-2016. Has had hyper salivation and foaming at the mouth. Owner thinks that after exposure to 24-D weed killer sometime before 3/20/2016 she started to have seizures. RDVM began Keppra and increased her dose up to 33mg/kg and added Diazepam PO later on.

Physical Exam: Bloodwork – non-regenerative anemia, low LYM and EOS; mildly high PHOS (7). Urinalysis – SG 1.044. Rads nsf

DX

The computed tomographic findings are suggestive for an intraaxial mass lesion within the right cerebral hemisphere

Image Interpretation

CT of the head, plain and post contrast – The computed tomography of the head reveals an irregular shaped rim-enhancing
lesion with hypoattenuating center within the temporal lobe of the right cerebral
hemisphere. A mass effect with cerebral midline shift as well as shift of the thalamus
to the left and compression of the right lateral ventricle is noted. The surrounding brain
parenchyma presents an ill-defined decrease in attenuation values.
The skull conformation is typical for a brachycephalic dog. The frontal sinuses are not
developed. There is mild incidental skull bone asymmetry.
The middle and external ears as well as nasal cavities are normal. Multiple teeth are
absent. There is generalized chronic periodontal disease with marked jaw bone atrophy
affecting all quadrants

Outcome

An intraaxial neoplasia – such as glioma, round cell neoplasia or other – is most likely
here. However, in a Yorkshire Terrier a cavitating/granulomatous lesion associated
with meningoencephalitis – such as necrotizing leukencephalitis – has to be considered
as well.
CSF samples should be obtained for further definition and to rule out
meningoencephalitis.
A Cytarabinosid/Prednisolone protocol might be considered for treatment of a possible
meningoencephalitis or as diagnostic challenge. Radiation treatment may be discussed
with the owner for a possible intraaxial neoplasia.