WHO classification of tumours of the central nervous system

The following is a simplified (deprecated) version of the last 2007 WHO classification of the tumours of the central nervous system.^{[1] [2]} Currently, as of 2016, clinicians are using revised WHO grade 4th edition which incorporates recent advance in molecular pathology. The 4th revised edition, as the name implies, will soon be updated to catch up ever growing knowledge of this field.

Listed for each tumour are the WHO official name, the ICD-O code^[3] (with Arabic numeral, where /0 indicates "benign" tumour, /3 malignant tumour and /1 borderline tumour), and with Roman numeral the WHO Grade (a parameter connected with the "aggressiveness" of the tumour).^{[note 1]}

1. Tumours of neuroepithelial tissue[]

1.1. Astrocytic tumours (Astrocytomas, a type of brain tumor)

1.1.1 Pilocytic astrocytoma (ICD-O 9421/1, WHO grade I)

1.1.1a (ICD-O 9425/3, WHO grade II)

1.1.2 Subependymal giant cell astrocytoma (ICD-O 9384/1, WHO grade I)

1.1.3 Pleomorphic xanthoastrocytoma (ICD-O 9424/3, WHO grade II)

1.1.4 (ICD-O 9400/3, WHO grade II)

1.1.5 Anaplastic astrocytoma (ICD-O 9401/3, WHO grade III)

1.1.6.Glioblastoma (ICD-O 9440/3, WHO grade IV)

1.1.6a Giant cell glioblastoma (ICD-O 9441/3, WHO grade IV)

1.1.6b Gliosarcoma (ICD-O 9442/3, WHO grade IV)

1.1.7 Gliomatosis cerebri (ICD-O 9381/3, WHO grade III)

1.2. Oligodendroglial tumours

1.2.1 Oligodendroglioma (ICD-O 9450/3, WHO grade II)

1.2.2 Anaplastic oligodendroglioma (ICD-O 9451/3, WHO grade III)

1.3. Oligoastrocytic tumours

1.3.1 Oligoastrocytoma (ICD-O 9382/3, WHO grade II)

1.3.2 (ICD-O 9382/3, WHO grade III)

1.4. Ependymal tumours

1.4.1 Subependymoma (ICD-O 9383/1, WHO grade I)

1.4.2 Myxopapillary ependymoma (ICD-O 9394/1, WHO grade I)

1.4.3 Ependymoma (ICD-O 9391/3, WHO grade II)

1.4.4 (ICD-O 9392/3, WHO grade III)

1.5. Choroid plexus tumours

1.5.1 Choroid plexus papilloma (ICD-O 9390/0, WHO grade I)

1.5.2 ( ICD-O 9390/1, WHO grade II)

1.5.3 Choroid plexus carcinoma (ICD-O 9390/3, WHO grade III)

1.6. Other neuroepithelial tumours

1.6.1 Astroblastoma (ICD-O 9430/3, WHO grade I)

1.6.2 (ICD-O 9444/1, WHO grade II)

1.6.3 (ICD-O 9431/1, WHO grade I)

1.7. Neuronal and mixed neuronal-glial tumours

1.7.1 Dysplastic gangliocytoma of cerebellum (Lhermitte-Duclos) (ICD-O 9493/0)

1.7.2 (ICD-O 9412/1, WHO grade I)

1.7.3 Dysembryoplastic neuroepithelial tumour (ICD-O 9413/0, WHO grade I)

1.7.4 Gangliocytoma (ICD-O 9492/0, WHO grade I)

1.7.5 Ganglioglioma (ICD-O 9505/1, WHO grade I)

1.7.6 (ICD-O 9505/3, WHO grade III)

1.7.7 Central neurocytoma (ICD-O 9506/1, WHO grade II)

1.7.8 (ICD-O 9506/1, WHO grade II)

1.7.9 (ICD-O 9506/1, WHO grade II)

1.7.10 (ICD-O 9509/1, WHO grade I)

1.7.11 (ICD-O 9509/1, WHO grade I)

1.7.12 Paraganglioma (ICD-O 8680/1, WHO grade I)

1.8. Tumours of the pineal region

1.8.1 Pineocytoma (ICD-O 9361/1, WHO grade I)

1.8.2 (ICD-O 9362/3, WHO grade II, III)

1.8.3 Pineoblastoma (ICD-O 9362/3, WHO grade IV)

1.8.4 Papillary tumors of the pineal region (ICD-O 9395/3, WHO grade II, III)

1.9. Embryonal tumours

1.9.1 Medulloblastoma (ICD-O 9470/3, WHO grade IV)

1.9.1b (ICD-O 9471/3, WHO grade IV)

1.9.1c (ICD-O 9474/3, WHO grade IV)

1.9.2. CNS Primitive neuroectodermal tumour (ICD-O 9473/3, WHO grade IV)

1.9.2a CNS Neuroblastoma (ICD-O 9500/3, WHO grade IV)

1.9.3 Atypical teratoid/rhabdoid tumour (ICD-O 9508/3, WHO grade IV)

2. Tumours of cranial and paraspinal nerves[]

2.1 Schwannoma (ICD-O 9560/0, WHO grade I)

2.2 Neurofibroma (ICD-O 9540/0, WHO grade I)

2.3 (ICD-O 9571/0, 9571/3, WHO grade I, II, III)

2.4 Malignant peripheral nerve sheath tumour (MPNST) (ICD-O 9540/3, WHO grade II, III, IV)

3. Tumours of the meninges[]

3.1 Tumours of meningothelial cells

3.1.1 Meningioma (ICD-O 9530/0, WHO grade I)

3.1.1l (ICD-O 9539/1, WHO grade II)

3.1.1o Anaplastic meningioma (ICD-O 9530/3, WHO grade III)

3.2 Mesenchymal tumours

3.2.1 Lipoma (ICD-O 8850/0)

3.2.2 Angiolipoma (ICD-O 8861/0)

3.2.3 Hibernoma (ICD-O 8880/0)

3.2.4 Liposarcoma (ICD-O 8850/3)

3.2.5 Solitary fibrous tumour (ICD-O 8815/0)

3.2.6 Fibrosarcoma (ICD-O 8810/3)

3.2.7 Malignant fibrous histiocytoma (ICD-O 8830/3)

3.2.8 Leiomyoma (ICD-O 8890/0)

3.2.9 Leiomyosarcoma (ICD-O 8890/3)

3.2.10 Rhabdomyoma (ICD-O 8900/0)

3.2.11 Rhabdomyosarcoma (ICD-O 8900/3)

3.2.12 Chondroma (ICD-O 9220/0)

3.2.13 Chondrosarcoma (ICD-O 9220/3)

3.2.14 Osteoma (ICD-O 9180/0)

3.2.15 Osteosarcoma (ICD-O 9180/3)

3.2.16 Osteochondroma (ICD-O 9210/0)

3.2.17 Haemangioma (ICD-O 9120/0)

3.2.18 Epithelioid hemangioendothelioma (ICD-O 9133/1)

3.2.19 Haemangiopericytoma (ICD-O 9150/1, WHO grade II)

3.2.20 (ICD-O 9150/3, WHO grade III)

3.2.21 Angiosarcoma (ICD-O 9120/3)

3.2.22 Kaposi Sarcoma (ICD-O 9140/3)

3.2.23 Ewing Sarcoma - PNET (ICD-O 9364/3)

3.3 Primary melanocytic lesions

3.3.1 (ICD-O 8728/0)

3.3.2 Melanocytoma (ICD-O 8728/1)

3.3.3 Malignant melanoma (ICD-O 8720/3)

3.3.4 (ICD-O 8728/3)

3.4 Other neoplasms related to the meninges

3.4.1 Haemangioblastoma (ICD-O 9161/1, WHO grade I)

4. Tumors of the haematopoietic system[]

4.1 Malignant Lymphomas (ICD-O 9590/3)

4.2 Plasmocytoma (ICD-O 9731/3)

4.3 Granulocytic sarcoma (ICD-O 9930/3)

5. Germ cell tumours[]

5.1 Germinoma (ICD-O 9064/3)

5.2 Embryonal carcinoma (ICD-O 9070/3)

5.3 Yolk sac tumour (ICD-O 9071/3)

5.4 Choriocarcinoma (ICD-O 9100/3)

5.5 Teratoma (ICD-O 9080/1)

5.6 (ICD-O 9085/3)

6. Tumours of the sellar region[]

6.1 Craniopharyngioma (ICD-O 9350/1, WHO grade I)

6.2 Granular cell tumour (ICD-O 9582/0, WHO grade I)

6.3 Pituicytoma (ICD-O 9432/1, WHO grade I)

6.4 (ICD-O 8991/0, WHO grade I)

7. Metastatic Tumours[]

Tumors that originate outside CNS and spread secondarily to CNS via Hematogenous route or by direct invasion from adjacent tissues. Most common primary tumour site

7.1 Lung

7.2 Breast

7.3 Melanoma

7.4 Renal

7.5 Colorectal

Reference : WHO pathology of tumours of central nervous system-2007

History[]

1979 WHO classification (1st edition)[]

Zülch, Histological typing of tumours of the central nervous system. World Health Organization, Geneva

1993 WHO classification (2nd edition)[]

reflected the advances brought about by the introduction of immunohistochemistry into diagnostic pathology

Kleihues P, Burger PC, Scheithauer BW (eds) (1993) Histological typing of tumours of the central nervous system. World Health Organization international histological classification of tumours. Springer, Heidelberg

2000 WHO classification (3rd edition)[]

edited by Kleihues and Cavenee

Kleihues P, Cavenee WK (eds) (2000) World Health Organization Classification of Tumours. Pathology and genetics of tumours of the nervous system. IARC Press

2007 WHO classification (4th edition)[]

This is the classification used until 2015. This version covered many techniques to diagnose the disease. Which was also included in the textbook of neurosurgery (Youman 6th edition).

2016 WHO classification (4th revised edition)[]

This is the current version and is a substantial revision of the 4th edition. The reason it is not the 5th edition is to bring the CNS volume in line with other systems that were not up to 5th editions yet.

WHO classification (5th edition)[]

The 5th edition, which is likely to incorporate many of the proposed changes outlined by the cIMPACT-NOW (the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy - Not Official WHO). Its publication date is not readily available and it is currently listed as a future title on the IARC website.^[4]

WHO Classification of Tumours (Online Edition)[]

Since February 19 2020, the online version of the WHO tumors classification has been accessible online as a subscription service, which includes the revised 4th edition.^[5]

See also[]

• Grading of the tumors of the central nervous system

Notes[]

References[]

External links[]

• AFIP Course Syllabus - Astrocytoma WHO Grading Lecture Handout