C18.1Appendix
Code usage status
Primary diagnosis
May be used as the primary diagnosis
Apply only when it matches the confirmed diagnosis and the documented clinical record.
Specificity
Complete code in the classification
Use when the diagnosis matches and no exclusion applies.
- Chapter II
- Neoplasms
- Group C00-C97
- Malignant neoplasms U ác tính
- Official Vietnamese name
- U ác tính ở ruột thừa
Related C18 codes
C18
Malignant neoplasm of colon
C18.0
Primary diagnosis candidate
Caecum
C18.2
Primary diagnosis candidate
Ascending colon
C18.3
Primary diagnosis candidate
Hepatic flexure
C18.4
Primary diagnosis candidate
Transverse colon
C18.5
Primary diagnosis candidate
Splenic flexure
C18.6
Primary diagnosis candidate
Descending colon
C18.7
Primary diagnosis candidate
Sigmoid colon
C18.8
Primary diagnosis candidate
Overlapping lesion of colon
C18.9
Primary diagnosis candidate
Colon, unspecified
Clinical record checklist
View coding guide →- Confirm that the code matches the final documented diagnosis.
- Use one primary-diagnosis code and record only relevant additional conditions.
- Review Ministry indicators, inclusions, exclusions and notes.
- Do not infer a diagnosis beyond the clinical record.
2026 regulatory basis
Indicators are taken from columns 24–29 of the classification accompanying Circular 06/2026/TT-BYT, cross-referenced with Decision 1849/QĐ-BYT and Official Dispatch 4059/BYT-BH.
