CNS TUMORS IN VETERINARY MEDICINE-NOT AS SCARY AS IT SOUNDS

What is the most common primary brain tumor overall?

Meningioma

What are the most common primary brain tumors in dogs?

Meningioma, glioma, choroid plexus tumor, pituitary tumor

What is the most common primary brain tumor in cats?

Meningioma

What is the typical behavior of canine meningioma?

Can be malignant

What is the typical behavior of feline meningioma?

Usually benign

In which breeds is canine glioma more common?

Brachycephalic breeds

What age group of dogs is most commonly affected by brain tumors?

Older dogs, often around 8 years

What age group of cats is most commonly affected by brain tumors?

Older cats, often around 9 years

What is the sex predisposition for cat brain tumors?

Males and females both affected; males mentioned more frequently

How common are large animal CNS tumors?

Rare overall

What are classic clinical signs of brain tumors?

Slowly progressive signs, seizures, behavior change, circling, pacing, staring into space

What may be the only clinical sign of a brain tumor?

Seizures

What does peracute onset with a brain tumor suggest?

Increased intracranial pressure or decompensation

What are neuro exam clues for forebrain tumors?

Contralateral deficits, contralateral circling, absent postural reactions opposite lesion, head turn toward lesion

Can a forebrain tumor exam be normal?

Yes, many dogs with forebrain tumors can have a normal neuro exam early

What are common exam clues for brainstem tumors?

Usually vestibular signs or cranial nerve deficits

What should raise concern for a brain tumor in an older dog?

New seizures

Which breed is predisposed to glioma?

Boxers

What neurological issues can bulldogs and Frenchies experience?

Can get almost anything neurologically, including tumors

What could old dogs with acute vestibular signs indicate?

Ischemic infarct rather than a tumor

What is the definitive diagnosis for a brain tumor?

Histopathology/biopsy

Why is MRI important in brain tumor workup?

Determines location, extra-axial vs intra-axial vs intraventricular, and helps narrow differentials

What is an extra-axial brain mass?

Tumor arising outside the brain parenchyma and compressing inward

What is the most common extra-axial differential?

Meningioma

What are imaging clues for extra-axial tumors?

Broad-based dural contact, strong homogeneous contrast enhancement, severe increased intracranial pressure can occur

What is an intra-axial brain mass?

Tumor arising within brain parenchyma

What are the most common intra-axial differentials?

Glioma, granuloma, abscess

What is a clue for intra-axial imaging?

Often irregular, infiltrative, within parenchyma

What is an intraventricular tumor?

Tumor arising within the ventricular system

What effects do intraventricular tumors have?

Obstructive hydrocephalus and increased intracranial pressure

What are common intraventricular tumor differentials?

Choroid plexus tumor, ependymoma, occasionally invading glioma/oligodendroglioma

What are the emergency management goals for a brain tumor patient?

Control seizures, reduce cerebral edema/intracranial pressure, stabilize patient

What hyperosmolar agents are used for increased ICP?

Mannitol or hypertonic saline

What is the use of prednisone in brain tumor patients?

Helps reduce peritumoral edema

What is the use of acetazolamide in brain tumor patients?

Decreases CSF production

What is the palliative treatment for brain tumors?

Seizure control + corticosteroids +/- hyperosmolar therapy in acute cases

What are the treatment options for brain tumors?

Surgery, radiation therapy, palliative medical management

Can meningioma surgery in cats be curative?

Often can be curative

Is meningioma surgery in dogs more challenging?

Yes, complete excision is less common

What are some complications of brain tumor surgery?

Aspiration pneumonia, seizures, transient neuro worsening, bleeding

What is the prognosis pearl regarding tumor grade?

Lower tumor grade is better

What is a concern with atypical meningiomas?

Can metastasize

What is the best indication for radiation therapy?

Gliomas and incompletely resected tumors; also used for feline meningioma

What are the advantages of radiation therapy?

Less invasive than surgery

What are the disadvantages of radiation therapy?

Cost, repeated anesthesia, risk of radiation injury, no histopath diagnosis

How does spinal neoplasia compare with brain neoplasia?

Less common than brain tumors

What is the typical age for spinal neoplasia?

Usually older animals, though nephroblastoma affects young dogs

What are the main spinal tumor compartments?

Extradural, intradural-extramedullary, intramedullary

What is the most common spinal tumor compartment?

Extradural

What is the origin of extradural spinal tumors?

Usually vertebral or outside the cord compressing inward

What is the most common intradural-extramedullary spinal tumor?

Meningioma or lymphoma depending on species/site

What is an intramedullary spinal tumor?

Tumor within the spinal cord parenchyma

What is the clinical course of spinal tumors?

Usually slowly progressive and often asymmetric

What does pain in spinal tumors suggest?

Vertebral involvement/lysis or extradural disease

What does muscle atrophy with spinal tumors suggest?

Nerve root involvement

What may be seen if a cervical lesion affects a limb in spinal neoplasia?

Thoracic limb lameness/atrophy may be seen

What are examples of primary vertebral tumors?

Osteosarcoma, fibrosarcoma, chondrosarcoma, plasmacytoma

What is the most common primary vertebral tumor in dogs?

Osteosarcoma

What are examples of secondary vertebral tumors?

Hemangiosarcoma, mammary carcinoma, prostatic carcinoma

What is the best initial imaging for bony spinal tumors?

Radiographs

What is the best advanced imaging for spinal neoplasia staging/localization?

CT for bone, MRI for cord/soft tissues

What is a common spinal tumor in dogs and also important in cats?

Spinal meningioma

What is the treatment for spinal meningioma?

Surgical debulking +/- radiation +/- palliative steroids

What is the classic signalment for nephroblastoma?

Young dog, often German Shepherd or similar large breed, thoracolumbar region

What is the classic location for nephroblastoma?

T10-L3, especially around T11-T12

What is the treatment for nephroblastoma?

Surgical debulking +/- radiation

What is the classic species clue for spinal lymphoma?

Most common spinal tumor diagnosis in cats

What is the signalment for spinal lymphoma?

Often young cats, can affect nerve roots

What is a diagnosis clue for spinal lymphoma?

CSF may detect lymphoblasts

What is the treatment for spinal lymphoma?

Chemotherapy +/- surgery/radiation depending on case

What is more common in cats than brain oligodendroglioma?

Spinal oligodendroglioma

Where are common sites for peripheral nerve sheath tumors?

Brachial plexus and trigeminal nerve

What are clinical signs of PNST in the brachial plexus?

Progressive thoracic limb lameness, muscle atrophy, reduced reflexes, possible Horner syndrome

What is the presentation of PNST in the trigeminal nerve?

Can mimic masticatory muscle disease or cause unilateral masticatory muscle atrophy

What factor worsens the prognosis for PNST?

Worse if spinal cord involvement is present

What is the treatment for PNST in the brachial plexus?

Amputation plus rhizotomy, often followed by radiation

What is the treatment for PNST in the trigeminal nerve?

Surgery/debulking +/- radiation

What is a high-yield rule for brain tumors?

Old dog + new seizures = brain tumor until proven otherwise

What is a high-yield rule for spinal tumors?

Slowly progressive, asymmetric, painful myelopathy = think neoplasia

What is the only definitive way to diagnose tumor type?

Histopathology