Brain - CS Extension

Note 1: The tentorium cerebelli is an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes. The location of the tumor above or below the tentorium can help in determining the type of tumor; also most adult brain tumors are supratentorial, and most pediatric brain tumors are infratentorial. In the following list, note that ICD-O-3 codes C71.0 and C71.9 include both supratentorial and infratentorial subsites.
    Supratentorial sites by ICD-O-3 codes:
        C71.0, except hypothalamus, pallium, thalamus
        C71.1-C71.5
        C71.8: Corpus callosum, tapetum
        C71.9: Anterior cranial fossa, middle cranial fossa, suprasellar
    Infratentorial sites by ICD-O-3 codes:
        C71.0: Hypothalamus, pallium, thalamus
        C71.6-C71.7
        C71.9: Posterior cranial fossa
Note 2: If discontiguous spread is limited to circulating cells in cerebrospinal fluid (CSF), use code 710 in CS Extension. Code all other discontiguous spread in CS Mets at DX.

Code	Description	TNM 7 Map	TNM 6 Map	SS77 Map	SS2000 Map
050	Benign or borderline brain tumor	NA	NA	NA	NA
100	Supratentorial tumor confined to: Cerebral hemisphere (cerebrum) or meninges of cerebral hemisphere (one side): Frontal lobe Occipital lobe Parietal lobe Temporal lobe	NA	NA	L	L
110	Infratentorial tumor confined to cerebellum or meninges of cerebellum (one side or midline): Vermis Lateral lobes Median lobe of cerebellum	NA	NA	L	L
120	Infratentorial tumor confined to: Brain stem or meninges of brain stem (one side): Medulla oblongata Midbrain (mesencephalon) Pons Hypothalamus Thalamus	NA	NA	L	L
150	Confined to brain, NOS Confined to meninges, NOS	NA	NA	L	L
200	Infratentorial tumor: Both cerebellum and brain stem involved with tumor on one side	NA	NA	L	L
300	Confined to ventricles Tumor invades or encroaches upon ventricular system	NA	NA	L	L
400	Tumor crosses the midline Tumor involves contralateral hemisphere Tumor involves corpus callosum (including splenium)	NA	NA	RNOS	RNOS
500	Supratentorial tumor extends infratentorially to involve: Cerebellum Brain stem Hypothalamus Pallium Posterior cranial fossa Thalamus	NA	NA	RNOS	RNOS
510	Infratentorial tumor extends supratentorially to involve: Cerebrum (cerebral hemisphere) (excluding hypothalamus, pallium, thalamus) Anterior cranial fossa Corpus callosum Middle cranial fossa Suprasellar brain Tapetum	NA	NA	RNOS	RNOS
600	Tumor invades: Bone (skull) Major blood vessel(s) Meninges (e.g., dura) Nerves, NOS Cranial nerves Spinal cord/canal	NA	NA	RNOS	RNOS
700	OBSOLETE DATA RETAINED AND REVIEWED V0203 See codes 100-600 and 710, CS Mets at DX code 20 Circulating cells in cerebral spinal fluid (CSF) Nasal cavity Nasopharynx Posterior pharynx Direct extension outside central nervous system (CNS)	NA	NA	D	D
710	Circulating cells in cerebral spinal fluid (CSF)	NA	NA	D	D
750	Extension to: Nasal cavity Nasopharynx Posterior pharynx Other direct extension outside CNS	NA	NA	D	D
800	Further contiguous extension	NA	NA	D	D
950	No evidence of primary tumor	NA	NA	U	U
999	Unknown; extension not stated Primary tumor cannot be assessed Not documented in patient record	NA	NA	U	U