C38.0 vs C45.2
C38.0 and C45.2 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on C45.2
other malignant neoplasm of pericardium (C38.0)
C38.0
Malignant neoplasm of heart
Billable
- Chapter 2
- Neoplasms
- Section
- C30-C39
Use when the record says
- Malignant neoplasm of pericardium
C45.2
Mesothelioma of pericardium
Billable
- Chapter 2
- Neoplasms
- Section
- C45-C49
Indexed under
- Mesothelioma › site classification › pericardium (malignant)
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027