| CIEL | 169877 | Undifferentiated carcinoma of endometrium | Non-standard |
| CIEL | 169886 | Primary undifferentiated carcinoma of thyroid gland | Non-standard |
| ICDO3 | 8020/3-C10.9 | Carcinoma, undifferentiated, NOS, of oropharynx, NOS | Non-standard |
| ICDO3 | 8020/3-C13.9 | Carcinoma, undifferentiated, NOS, of hypopharynx, NOS | Non-standard |
| ICDO3 | 8020/3-C15.9 | Carcinoma, undifferentiated, NOS, of esophagus, NOS | Non-standard |
| ICDO3 | 8020/3-C16.9 | Carcinoma, undifferentiated, NOS, of stomach, NOS | Non-standard |
| ICDO3 | 8020/3-C22.1 | Carcinoma, undifferentiated, NOS, of intrahepatic bile duct | Non-standard |
| ICDO3 | 8020/3-C31.9 | Carcinoma, undifferentiated, NOS, of accessory sinus, NOS | Non-standard |
| ICDO3 | 8020/3-C33.9 | Carcinoma, undifferentiated, NOS, of trachea | Non-standard |
| ICDO3 | 8020/3-C34.9 | Carcinoma, undifferentiated, NOS, of lung, NOS | Non-standard |
| ICDO3 | 8020/3-C54.1 | Carcinoma, undifferentiated, NOS, of endometrium | Non-standard |
| ICDO3 | 8020/3-C54.9 | Carcinoma, undifferentiated, NOS, of corpus uteri | Non-standard |
| ICDO3 | 8020/3-C56.9 | Carcinoma, undifferentiated, NOS, of ovary | Non-standard |
| ICDO3 | 8020/3-C73.9 | Carcinoma, undifferentiated, NOS, of thyroid gland | Non-standard |
| LOINC | 67200-6|LA15447-8 | Histopathologic type for primary colorectal cancer [PhenX]: Undifferentiated carcinoma | Non-standard |
| LOINC | 81190-1|LA15447-8 | Histologic type of Stomach cancer by WHO Classification: Undifferentiated carcinoma | Non-standard |
| LOINC | 84882-0|LA15447-8 | Histologic type in Colorectal cancer specimen by WHO classification: Undifferentiated carcinoma | Non-standard |
| MeSH | C537344 | Sinonasal undifferentiated carcinoma | Non-standard |
| OncoTree | EPDCA | Esophageal Poorly Differentiated Carcinoma (EPDCA) | Non-standard |
| SNOMED | 1208741006 | SMARCA4-deficient undifferentiated neoplasm of thorax | Non-standard |
| SNOMED | 1255392007 | Undifferentiated carcinoma of trachea | Non-standard |
| SNOMED | 1255393002 | Undifferentiated carcinoma of lung | Non-standard |
| SNOMED | 1255394008 | Undifferentiated carcinoma of endometrium | Non-standard |
| SNOMED | 1259386005 | Primary undifferentiated carcinoma of ovary | Non-standard |
| SNOMED | 1259444003 | Primary undifferentiated carcinoma of nasal sinus | Non-standard |