Tumor Origin | Predilection Sites | Species | Incidence |
---|---|---|---|
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 |