CNS neoplasms are most common in…
- brachycephalic breeds & other dogs
- cats
- older animals
- 1° more commonly
- benign can kill too
Meningioma
Most common in FELINE and non-brachyocephalic dogs
- Brain > cord
- mass on outer area of brain
Dogs
- associated with frontal lobes or olfactory bulbs
- less progesterone receptors –> worse prog
Cat
- -Subratentoral
- lateral / 3rd ventricle tela coroidea
2 types of gliomas
- Astrocytomas
- Oligodendroglioma
- distinguishable w/ imaging
- grossly indistinct
Astrocytomas
- Brachyocephalic breeds & other dogs
- Histological grades
- diffuse = low grade
- anaplastic = intermediate grade
- glioblastoma multiforme = high grade
- Immunohistochem
- for Glial fibrillary acidic protein (GFAP)
- intermediate filament of astrocytes
- supportive, not definitive
- for Glial fibrillary acidic protein (GFAP)
Oligodendroglioma
Common tumor in brachycephalic breeds
- usually a distinct mass
- **Mucinous / hemorrhagic degeneration
- commonly supratentorial
Ependymoma
- Contiguous with ependymal lining (line ventricles)
– especially lateral or 3rd ventricles
– central canal of cord - may form Rosettes – usually central
- may see ciliated cells
Choroid plexus tumors
- Papilloma more common (4th ventricle)
- Carcinoma has mitotic figures and invasive growth
- lateral or 3rd ventricles or protruding from the 4th ventricle at the cerebellopontine angle
2 types of Hematopoietic tumors
- Reticulosis / Histocytic sarcoma
2. Lymphomas
Histocytic sarcomas
Histiocytic origin
- usually cerebral / cerebellar white matter
- angiocentric
- discrete nodules
Lymphomas
** infiltrate of cerebrum & spinal cord
Cattle
- cauda equina = BLV-associated lymphoma
Cat
- THE most common cause of Feline Spinal tumor
- 2nd most common brain tumor
common 2° (metastatic) CNS tumors
Adjacent bone tumors --Multilobular tumor of bone --Osteosarcoma --Multiple myeloma Other metastatic tumors -- Mammary carcinoma -- Canine hemangiosarcoma -- Melanoma
Peripheral nerve sheath tumors
Origin - schwann cells /fibroblasts/ perineurial cells
= schwanoma/neurofibroma/perineurioma
Dog
- brachial plexus > Trigeminal (CN 5)
Cattle
- CN 8
- brachial plexus
- autonomic NS
Medulloblastma
Embryonal tumor
• Primative neuroepithelial cells
• External granular layer of cerebellum
• Calves / Puppies
Spinal cord Nephroblastoma
Embryonal tumor
• Extramedullary T10 -L2
• Lg breed dogs (German Shepherd Dog)
Histo
• blastemal cells, epithelial lined tubules, and glomeruloid structures
