Primary Tumors

Nerve cells

Ganglioneuroma (gangliocytoma)

Ganglioneuroblastoma

Neuroblastoma

Primitive neuroectodermal tumors

Variable, eg, cerebellum, cranial nerve roots, eye, cervical ganglion

Dogs

Rare

Neuroepithelium

Ependymoma

Third and lateral ventricles

Dogs, cats

Uncommon

Nephroblastoma

Meninges, thoracolumbar spinal cord

Dogs (German Shepherd)

Uncommon

Choroid plexus papilloma

Fourth ventricle

Dogs

Common

Neuroglia

Astrocytoma (fibrillary, protoplasmic, gemistocytic, anaplastic)

Piriform area, convexity of cerebral hemispheres, thalamus, hypothalamus

Dogs (brachycephalic), cats

Common

Oligodendroglioma

Cerebral hemispheres

Dogs (brachycephalic)

Common

Glioblastoma

As for astrocytoma

Dogs (brachycephalic)

Uncommon

Spongioblastoma

Variable, eg, ependymal surfaces, cerebellum, optic nerve and tracts

Dogs (brachycephalic)

Rare

Medulloblastoma

Cerebellum

Dogs, cats

Uncommon

Gliomas (unclassified)

Periventricular areas, especially in cerebral hemispheres

Dogs

Common

Peripheral nerves and nerve sheaths

Nerve sheath tumors (schwannoma, neurofibrosarcoma, neurofibroma, neurinoma)

Peripheral nerves

Dogs, cats

Common

Meninges, vessels, and other mesenchymal structures

Meningiomas (fibrous, transitional, psammomatous, angiomatous, papillary, granular cell, myxoid, anaplastic)

Convexities of cerebral hemispheres and floor of the vault

Dogs (dolicocephalic), cats

Common

Angioblastoma

Variable

Dogs, cats

Rare

Sarcoma

Variable

Dogs, cats

Common

Histiocytic sarcoma (focal granulomatous meningoencephalomyelitis reticulosis)

Cerebral hemispheres and brain stem

Dogs, cats

Rare (in dogs)

Pineal gland, pituitary gland, and craniopharyngeal duct

Pinealoma

Pineal body

Dogs

Rare

Pituitary adenoma

Pituitary gland

Dogs (brachycephalic), cats

Common

Craniopharyngioma

Hypophyseal- infundibular areas

Dogs

Rare

Heterotopic tissues (malformation tumors)

Epidermoid, dermoid, teratoma, teratoid, intra-arachnoid cyst

Variable (fourth ventricle and cerebellopontine angle for epidermoid, quadrigeminal cistern for intra-arachnoid cyst)

Dogs

Rare

Germ cell tumors

Base of brain above sella turcica

Dogs

Rare

Hamartoma

Variable (eg, hypothalamus)

Dogs

Rare

Secondary Tumors

Metastatic tumors

Mammary gland adenocarcinoma, pulmonary carcinoma, prostatic carcinoma, chemodectoma, malignant melanoma, lymphosarcoma, salivary gland adenocarcinoma, hemangiosarcoma, etc

Variable

Dogs, cats

Relatively common

Primary tumors from surrounding tissues

Osteosarcoma, lipoma, osteochondroma, chondrosarcoma, fibrosarcoma, nasal adenocarcinoma, hemangiosarcoma, multiple myeloma, calcifying aponeurotic fibromatosis, epidermoid cyst, etc

Variable

Dogs, cats

Relatively common