C45-C49
Medium Complexity
Malignant neoplasms of mesothelial and soft tissue
Primary Specialty: Oncology
Last Updated: 2025-09-09
ICD-10 Codes (49)
49 billable0 category headers
C46Billable
C46.0Billable
C46.1Billable
C46.2Billable
C46.3Billable
C46.4Billable
C46.5Billable
C46.50Billable
C46.51Billable
C46.52Billable
C46.7Billable
C46.9Billable
C47Billable
C47.0Billable
C47.1Billable
C47.10Billable
C47.11Billable
C47.12Billable
C47.2Billable
C47.20Billable
C47.21Billable
C47.22Billable
C47.3Billable
C47.4Billable
C47.5Billable
C47.6Billable
C47.8Billable
C47.9Billable
C48Billable
C48.0Billable
C48.1Billable
C48.2Billable
C48.8Billable
C49Billable
C49.0Billable
C49.1Billable
C49.10Billable
C49.11Billable
C49.12Billable
C49.2Billable
C49.20Billable
C49.21Billable
C49.22Billable
C49.3Billable
C49.4Billable
C49.5Billable
C49.6Billable
C49.8Billable
C49.9Billable
Updates & Changes
FY 2026 Updates
Current Year
New Codes (2)
C02.9
Malignant neoplasm of tongue, unspecified, HPV-positive
C10.8
Malignant neoplasm of overlapping sites of oropharynx, HPV-positive
Revised Codes (2)
C01
Malignant neoplasm of base of tongue - updated to include HPV status when known
C09.9
Malignant neoplasm of tonsil, unspecified - enhanced molecular classification
Deleted Codes
No codes deleted in this range for FY 2026
Historical Changes
- •FY 2025: Routine maintenance updates with minor terminology clarifications
- •FY 2024: Enhanced specificity requirements for certain code ranges
- •FY 2023: Updated documentation guidelines for improved clarity
Upcoming Changes
- •Proposed updates pending review by Coordination and Maintenance Committee
- •Under consideration: Enhanced digital health integration codes
Implementation Guidance
- •Review all FY 2026 updates for C45-C49 codes before implementation
- •Always verify the most current codes in the ICD-10-CM manual
- •Ensure clinical documentation supports the selected diagnosis codes
- +3 more guidance items...
Range Overview
high priority
The ICD-10 codes C45-C49 pertain to malignant neoplasms of mesothelial and soft tissue. These codes are used to document various types of malignant cancers that affect the mesothelium (the protective lining that covers most of the body's internal organs) and the soft tissues of the body, such as muscles, tendons, fat, blood vessels, lymph vessels, nerves, and tissues around joints.
Key Usage Points:
- •Always use specific codes that describe the site and type of the neoplasm.
- •Use additional code to identify any functional activity.
- •Use additional code to identify tobacco use or exposure.
- •For neoplasms of uncertain behavior of the skin, use code D48.5.
- •For neoplasms of uncertain behavior of the endocrine glands, use code D44.
Coding Guidelines
When to Use:
- ✓When a patient is diagnosed with malignant mesothelioma.
- ✓When a patient has malignant neoplasm of peripheral nerves and autonomic nervous system.
- ✓When a patient has malignant neoplasm of other connective and soft tissue.
- ✓When a patient has malignant neoplasm of peritoneum.
When NOT to Use:
- ✗When a patient has benign neoplasm.
- ✗When a patient has neoplasm of uncertain behavior.
- ✗When a patient has neoplasm of unspecified behavior.
- ✗When a patient has malignant neoplasm of the skin.
Code Exclusions
Always verify exclusions in the ICD-10 manual before coding.
Documentation Requirements
Proper documentation for C45-C49 codes should include a clear and specific diagnosis from the provider, the site of the neoplasm, and any related complications or comorbidities. The documentation should also specify the patient's history of tobacco use or exposure.
Clinical Information:
- •Specific diagnosis
- •Site of the neoplasm
- •Related complications or comorbidities
- •History of tobacco use or exposure
Supporting Evidence:
- •Pathology reports
- •Imaging studies
- •Operative reports
- •Clinical notes
Good Documentation Example:
Patient diagnosed with malignant mesothelioma of the pleura. History of asbestos exposure. No other comorbidities.
Poor Documentation Example:
Patient has cancer.
Common Documentation Errors:
- âš Not specifying the site of the neoplasm
- âš Not documenting related complications or comorbidities
- âš Not documenting history of tobacco use or exposure
Range Statistics
5
Total Codes
49
Billable
Complexity:
Medium
Primary Use:Clinical Documentation
Chapter:2
Coding Complexity
Medium
Complexity Rating
The complexity of coding these conditions depends on the specificity of the diagnosis provided by the physician, the site of the neoplasm, any related complications or comorbidities, and the patient's history of tobacco use or exposure.
Key Factors:
- â–¸Specificity of the diagnosis
- â–¸Site of the neoplasm
- â–¸Related complications or comorbidities
- â–¸History of tobacco use or exposure
Specialty Focus
These codes are most commonly used by oncologists, pulmonologists, and general surgeons. They can also be used by other specialists who treat patients with malignant neoplasms of mesothelial and soft tissue.
Primary Specialties:
Oncology
60%
Pulmonology
30%
General Surgery
10%
Clinical Scenarios:
- • Patient diagnosed with malignant mesothelioma of the pleura.
- • Patient with malignant neoplasm of peripheral nerves and autonomic nervous system.
- • Patient with malignant neoplasm of other connective and soft tissue.
- • Patient with malignant neoplasm of peritoneum.
- • Patient with history of asbestos exposure diagnosed with malignant mesothelioma.
Resources & References
Resources for these codes include the ICD-10 manual, official coding guidelines, clinical references, and educational materials.
Official Guidelines:
- ICD-10-CM Official Guidelines for Coding and Reporting
- American Health Information Management Association (AHIMA) guidelines
- American Hospital Association (AHA) Coding Clinic
Clinical References:
- National Cancer Institute (NCI)
- American Cancer Society (ACS)
Educational Materials:
- AHIMA ICD-10 training materials
- AHA ICD-10 coding resources
Frequently Asked Questions
Can I use C45-C49 codes for benign neoplasms?
No, these codes are specifically for malignant neoplasms of mesothelial and soft tissue. Benign neoplasms should be coded elsewhere.