Topographic Sites

Cerebral Meninges
ICD-O-3 Term
C70.0 Cerebral meninges
C70.1 Spinal meninges
C70.9 Meninges, NOS

ICD-O-3 Term Supratentorial Infratentorial
C71.0 Cerebrum X  
Basal ganglia X  
Central white matter X  
Cerebral cortex X  
Cerebral hemisphere X  
Corpus striatum X  
Globus pallidus X  
Hypothalamus   X
Insula X  
Internal capsule X  
Island of Reil X  
Operculum X  
Pallium   X
Putamen X  
Rhinencephalon X  
Supratentorial brain, NOS X  
Thalamus   X
C71.1 Frontal lobe    
C71.2 Temporal lobe    
C71.3 Parietal lobe    
C71.4 Occipital lobe    
C71.5 Ventricle, NOS*    
Cerebral ventricle    
Choroid plexus, NOS*    
Choroid plexus of lateral ventricle X  
Choroid plexus of third ventricle X  
Lateral ventricle, NOS X  
Third ventricle, NOS X  
C71.6 Cerebellum, NOS   X
Cerebellopontine angle   X
Vermis of cerebellum   X
C71.7 Brain stem   X
Cerebral peduncle   X
Basis pedunculi   X
Choroid plexus of fourth ventricle   X
Fourth ventricle, NOS   X
Infratentorial brain, NOS   X
Medulla oblongata   X
Midbrain   X
Olive   X
Pons   X
Pyramid   X
C71.8 Overlapping lesion of brain    
Corpus callosum X  
Tapetum X  
C71.9 Brain, NOS*    
Intracranial site*    
Cranial fossa, NOS*    
Anterior cranial fossa X  
Middle cranial fossa X  
Posterior cranial fossa   X
Suprasellar X  

Spinal Cord and Other Central Nervous System
ICD-O-3 Term
C72.0 Spinal cord
C72.1 Cauda equina
C72.2 Olfactory nerve
C72.3 Optic nerve
C72.4 Acoustic nerve
C72.5 Cranial nerve, NOS
C72.8 Overlapping lesion of brain and central nervous system
C72.9 Nervous system, NOS

* More anatomical information is needed before determining whether a lesion at this location is infra- or supratentorial.

ICD-O-3 Coding Issues

For some histologic types, it is difficult to determine if the primary site is intracranial or the skull (C41.0). Tumors that originate in the skull are not intracranial. The malignant tumors are reportable regardless of origin, but non-malignant tumors that originate in the skull are not reportable.

  • Chondroma (9220/0) is a benign tumor of cartilage cells. The ICD-O-3 Manual shows the code for bone in parentheses next to the morphology. Review the record carefully to determine if the tumor originated in bone or in an intracranial site. Because chondroma is a benign tumor, only complete an abstract if the primary tumor is in an intracranial site. A chondroma of the skull is not reportable.
  • Chordoma is a malignant tumor arising from the embryonic notochord, and chondrosarcoma (9220/3) is a malignant tumor of cartilage cells. These tumor histologies are reportable, but you must determine if the primary site is bone or an intracranial site because the intracranial tumors are analyzed separately.

When ICD-O-3 was published, the code for pilocytic astrocytoma changed from malignant behavior (3) to borderline behavior (1). Registrars were instructed to continue to assign the code with malignant behavior. For data consistency, continue to assign the malignant behavior code (3) to pilocytic astrocytoma even after non-malignant CNS cases are collected.

Intracranial schwannoma (9560/0) is reportable for cases diagnosed January 1, 2004 and later. It is difficult to determine the intracranial site of a schwannoma. Assign the primary site for intracranial schwannoma to cranial nerves NOS (C72.5) when the site is not documented in the health record.