EOD Primary Tumor
Notes
**Note:** The cortex of a bone is the dense outer shell that provides strength to the bone; the spongy center of a bone is the cancellous portion. The periosteum of the bone is the fibrous membrane covering of a bone that contains the blood vessels and nerves; the periosteum is similar to the capsule on a visceral organ.| Code | Description | SS2018 T |
|---|---|---|
| 100 | Involvement of one vertebral segments | L |
| 200 | Involvement of two adjacent vertebral segments | L |
| 300 | Involvement of three adjacent vertebral segments | L |
| 400 | Involvement of four or more adjacent vertebral segments | L |
| 450 | Confined to spine, NOS (number of segments involved not known) Localized, NOS | L |
| 500 | Involvement of nonadjacent vertebral segments | RE |
| 600 | Extension beyond periosteum to surrounding tissues, including adjacent skeletal muscle(s) | RE |
| 650 | Spinal canal | D |
| 700 | Gross vascular invasion Tumor thrombus in great vessels | D |
| 800 | No evidence of primary tumor | U |
| 999 | Unknown; extension not stated Primary tumor cannot be assessed Not documented in patient record Death Certificate Only | U |