BASIC (04-10)

DI 24585.001 Evaluation of Tumors of the Central Nervous System (tumors of the brain and spinal cord)

A. General

There are a number of classification systems that medical sources use to indicate the grades of tumors of the central nervous system. The World Health Organization (WHO) classification of tumors of the central nervous system (WHO Classification of Tumours of the Central Nervous System, 2007)1 is the most commonly used classification system. We consider a tumor of the central nervous system to be malignant if it is classified as grade II or higher under the WHO system (see 13.00K6 and 113.00K4). (See DI 34001.034 and DI 34005.113.)

B. How to determine the WHO grade of a tumor of the central nervous system

If the medical evidence uses a classification system other than the WHO system, refer to the tables below to determine the tumor grade under the WHO system. If the tumor is WHO grade I, evaluate the tumor under the criteria in listings 11.05 and 111.05. (See DI 34001.030 and DI 34005.111.) If the tumor is WHO grade II, evaluate the tumor under listing 13.13A3 or 113.13C. If the tumor is grade III or IV under the WHO or another classification system, consider the tumor to be highly malignant and evaluate it under the criteria in listings 13.13A1 or 13.13A2 and 113.13A or 113.13B.

  

Table A. WHO Grade I Tumors

Type of tumor

Name of tumor

Grade of tumor

Astrocytic tumors

Pilocytic astrocytoma2

I

Subependymal giant cell

I

Ependymal tumors

Myxopapillary ependymoma

I

Subependymoma

I

Choroid Plexus tumors

Choroid plexus papilloma

I

Other Neuroepithelial tumors

Angiocentric glioma

I

Neuronal and Mixed Neuronal-glial tumors

Desmoplastic infantile astrocytoma

I

Desmoplastic infantile ganglioglioma

I

Dysembryoplastic neuroepithelial tumor

I

Gangliocytoma

I

Papillary glioneuronal tumor

I

Paraganglioma of the spinal cord

I

Rosette-forming glioneuronal tumor of the fourth ventricle

I

Pineal tumors

Pineocytoma3

I

Schwannomas

Cellular

I

Melanotic

I

Plexiform

I

Neurofibromas

Plexiform

I

Perineurioma

Intraneural perineurioma

I

Meningiomas4

Angiomatous

I

Fibrous (fibroblastic)

I

Lymphoplasmacyte-rich

I

Meningiothelial

I

Metaplastic

I

Microcystic

I

Psammomatous

I

Secretory

I

Transitional (mixed)

I

Mesenchymal

Angiolipoma

I

Chondroma

I

Epitheloid haemangioendothelioma

I

Haemangioma

I

Hibernoma

I

Leiomyoma

I

Lipoma

I

Osteochondroma

I

Osteoma

I

Rhabdomyoma

I

Solitary fibrous histocytoma

I

Melanomas

Diffuse melanocytosis

I

Melanocytoma

I

Other Tumors related to meninges

Haemangioblastoma

I

Teratomas

Mature teratoma

I

Tumors of the Sellar Region

Adamantinomatous craniopharyngioma

I

Craniopharyngioma

I

Granular cell tumor

I

Papillary craniopharyngioma

I

Pituicytoma

I

Spindle cell oncocytoma of the adenohypophysis

I

   

Table B. WHO Grade II Tumors

Type of tumor

Name of tumor

Grade of tumor

Astrocytic tumors

Diffuse astrocytoma

II

Fibrillary astrocytoma

II

Gemistocytic astrocytoma

II

Pilomyxoid astrocytoma

II

Pleomorphic xanthoastrocytoma

II

Protoplasmic astrocytoma

II

Oligodendroglial tumors

Oligodendroglioma

II

Oligoastrocytic tumors

Oligoastrocytoma

II

Ependymomas

Cellular

II

Clear Cell

II

Papillary

II

Tanycytic

II

Choroid Plexus tumors

Atypical choroid plexus papilloma

II

Other Neuroepithelial tumors

Chordoid glioma of the third ventricle

II

Neuronal and Mixed Neuronal-glial tumors

Central neurocytoma

II

Cerebellar liponeurocytoma

II

Extraventricular neurocytoma

II

Meningiomas

Atypical meningioma

II

Chordoid meningioma

II

Clear cell meningioma

II

Mesenchymal Tumors

Haemangiopericytoma

II

   

Table C. WHO Grade III Tumors

Type of tumor

Name of tumor

Grade of tumor

Astrocytic Tumors

Anaplastic astrocytoma5

III

Gliomatosis cerebri

III

Oligodendroglial Tumors

Anaplastic oligoastrocytoma

III

Anaplastic oligodendroglioma

III

Ependymal Tumors

Anaplastic ependymoma

III

Choroid Plexus Tumors

Choroid plexus carcinoma

III

Other Neuronal and Mixed Neuronal-Glial Tumors

Anaplastic ganglioma

III

Meningiomas

Anaplastic (malignant) meningioma

III

Papillary meningioma

III

Rhabdoid meningioma

III

Mesenchymal Tumors

Anaplastic haemangiopericytoma

III

   

Table D. WHO Grade IV Tumors

Type of tumor

Name of tumor

Grade of tumor

Astrocytic Tumors

Glioblastoma

IV

Tumors of the Pineal Region

Pineoblastoma

IV

Embryonal Tumors

Atypical teratoid/rhabdoid tumor

IV

Central nervous system Primitive neuroectodermal tumors (PNETs)

IV

Medulloblastoma6

IV


Footnotes:

[1]

Louis, D.N., Ohgaki, H., Cavenne, W.K. (eds), WHO Classification of Tumours of the Central Nervous System, IARC, Lyon, (2007).

[2]

Includes juvenile pilocytic astrocytoma, a slower growing tumor that occurs mostly in children and young adults. The tumor forms in the brain more often than the spinal cord. (National Cancer Institute, http://www.cancer.gov/dictionary/ .)

[3]

Some organizations and references, such as the National Cancer Institute, may classify pineocytoma as a grade II tumor. For the purposes of listings 13.13 and 113.13, we consider pineocytoma to be a WHO grade I tumor.

[4]

Most meningiomas are benign and approximately 80 percent are treated successfully with surgery. Meningiomas represent 13 percent to 27 percent of all intracranial tumors and are more common in females and older age groups. (Marosi, C. et al., Meningioma, Critical Reviews in Oncology/Hematology, Aug;67(2), 153-171 (2008).)

[5]

WHO grade III anaplastic astrocytoma and grade IV glioblastoma multiforme include diffuse intrinsic brain stem gliomas, which are most common in children.

[6]

Medulloblastoma is the most common brain tumor in childhood and one-third of these tumors occur during the first years of life. Adverse effects of radiation therapy in children include hearing loss, cognitive decline, endocrine abnormalities, and vascular complications. (Mueller, S. et al., Pediatric brain tumors: Current treatment strategies and future therapeutic approaches, Neurotherapeutics, Jul;6(7), 570-586 (2009).) Medulloblastomas and other primitive neuroectodermal tumors (PNETs) meet listing 13.13A2 or listing 113.13B if they have documented metastases.


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DI 24585.001 - Evaluation of Tumors of the Central Nervous System (tumors of the brain and spinal cord) - 07/24/2015
Batch run: 07/24/2015
Rev:07/24/2015