Page 1311 - Clinical Small Animal Internal Medicine

136 Central Nervous System Tumors in Dogs and Cats 1249

mortality rate, but will continue to decrease as experi-
VetBooks.ir ence with the procedure increases. Currently, not all
patients receive histopathologic confirmation due to the
cost and risk of potential complications. To mitigate
some risk, cytology can be considered instead but this
too is not commonly performed. Hence many patients
are treated without a true diagnosis.
Dogs with suspected hyperadrenocorticism and cats
with suspected acromegaly or insulin resistance should
be evaluated with CT or MRI. Small pituitary masses
may escape detection with CT but larger lesions can be
detected with CT especially with newer generation CT
imagers.

Spinal Cord

As with intracranial neoplasia, full staging including
three‐view thoracic radiographs, full blood analysis,
urinalysis, and abdominal ultrasound should be per-
Figure 136.1 T1‐weighted post‐contrast (gadolinium) coronal formed before or in conjunction with advanced imag-
image of a frontal lobe mass in a 9‐year‐old, male, golden ing (CT/MRI/PET). Survey spinal radiographs should
retriever. Surgical excision was performed. Histopathology was be performed to evaluate for possible bony lysis.
consistent with histiocytic sarcoma. The dog’s only symptom Although rarely helpful, lysis may be present and may
was acute onset of seizures. indicate a neoplastic process is emanating from out-
side the CNS with secondary invasion to spinal cord, as
in the case of skeletal neoplasia (osteosarcoma, chon-
drosarcoma) or rarely soft tissue tumors (soft tissue
sarcomas, carcinomas). As with intracranial tumors,
due to cost, need for advanced diagnostic equipment
and risk of potential complications, many patients
with spinal neoplasia are treated without a definitive
diagnosis.

Treatment/Prognosis

Central nervous system neoplasia, like other tumors, can
be managed with a combination of surgery, radiation,
and chemotherapy. However, the veterinary literature is
limited to uncontrolled and retrospective studies based
on relatively small numbers of patients.

Medical Management

Nonspecific treatment options include antiinflamma-
tory doses of corticosteroids for peritumoral edema and
Figure 136.2 T1‐weighted postcontrast (gadolinium) sagittal anticonvulsant therapy if seizures are a component of the
image of a cervical spinal cord tumor in an 11‐year‐old male
castrated boxer, presenting for acute tetraparesis with associated clinical presentation. Phenobarbital, Keppra® (leveti-
neck pain. The mass is consistent with a meningioma given the racetam), and zonisamide are all options for control
extraaxial location and presence of a dural tail at the caudal of seizures. Unfortunately, supportive care alone is asso-
extent of the mass. Surgical excision and biopsy were not ciated with a poor prognosis in the vast majority of
performed. The dog received 48 Gy radiation therapy (16 × 3 Gy) patients. Published survival times in such a group are
and adjuvant hydroxyurea with nearly complete resolution of the
neurologic signs/neck pain and was alive two years following generally between one and 10 weeks but individual
treatment. patients may far exceed this.