The site(s) of disease identified outside the bone marrow, including the present of blasts in the Cerebrospinal fluid (CSF).
National Codes:
| T | Testes (Retired 01 April 2017) | 
| C | CNS (Central Nervous System) (Retired 01 April 2017) | 
| O | Other (Retired 01 April 2017) | 
| 1 | CNS1 (Central Nervous System) (less than 5 WBC (White blood cells) in the CSF (Cerebrospinal fluid) without blasts | 
| 2 | CNS2 (Central Nervous System) (less than 5 (White blood cells) in the CSF (Cerebrospinal fluid) with blasts) | 
| 3 | CNS3 (Central Nervous System) (greater than or equal to 5 (White blood cells) in the CSF (Cerebrospinal fluid) with blasts) | 
| 4 | Testes | 
| 9 | Other | 
This attribute is also known by these names:
| Context | Alias | 
|---|---|
| plural | EXTRAMEDULLARY DISEASE SITES |