Schema Discriminator 1: Primary Peritoneum Tumor
This input is used for staging
Description
The GIST chapter includes a schema discriminator for C481 for location of the primary tumor because all the peritoneum structures are coded to C481, but two separate stage tables are used to derive the TNM values.Notes
**Note:** **Schema discriminator for C481** * Since both omental and peritoneal gastrointestinal stromal tumors (GIST) are coded with the same ICD-O-3 topography code (C481), this data item must be used to identify the appropriate AJCC stage table.| Code | Description | Stage Table |
|---|---|---|
| 1 | Mesentery Mesoappendix Mesocolon Pelvic peritoneum Rectouterine pouch - Cul de sac - Pouch of Douglas Other specified peritoneal site |
Small Intestinal, Esophageal, Colorectal, Mesenteric and Peritoneal GIST |
| 2 | Omentum | Gastic and Omental GIST |
| 9 | Unknown or no information Not documented in medical record |
Small Intestinal, Esophageal, Colorectal, Mesenteric and Peritoneal GIST |
| <BLANK> | Primary Site is NOT C481, Discriminator is not necessary |