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v1.0.0
ICD-10 Guide
ICD-10 CodesC34.90

C34.90

Billable

Malignant neoplasm of unspecified part of unspecified bronchus or lung

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/05/2025

Code Description

ICD-10 C34.90 is a billable code used to indicate a diagnosis of malignant neoplasm of unspecified part of unspecified bronchus or lung.

Key Diagnostic Point:

C34.90 refers to a malignant neoplasm located in the bronchus or lung, where the specific site is not identified. This code is often used when the exact location of the tumor cannot be determined, which can occur in cases where imaging studies are inconclusive or when the tumor is diagnosed based on symptoms without a definitive site being established. Lung cancer is a leading cause of cancer-related mortality worldwide, with risk factors including smoking history, exposure to secondhand smoke, and environmental pollutants. The staging of lung cancer is critical for determining treatment options and prognosis, typically classified using the TNM system (Tumor, Node, Metastasis). Molecular markers, such as EGFR mutations and ALK rearrangements, play a significant role in targeted therapies. Treatment algorithms may include surgery, chemotherapy, radiation therapy, and immunotherapy, depending on the stage and specific characteristics of the cancer. Accurate coding is essential for appropriate treatment planning and reimbursement.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Unspecified site can lead to ambiguity in treatment planning.
  • Requires thorough documentation to justify the use of unspecified codes.
  • Potential overlap with other lung cancer codes that specify location.
  • Need for clear staging information to support coding decisions.

Audit Risk Factors

  • Use of unspecified codes without adequate documentation.
  • Inconsistent staging information.
  • Lack of molecular marker documentation.
  • Failure to update codes based on treatment changes.

Specialty Focus

Medical Specialties

Oncology

Documentation Requirements

Detailed pathology reports, imaging studies, and treatment plans.

Common Clinical Scenarios

Diagnosis of lung cancer based on imaging without a clear site, staging assessments.

Billing Considerations

Ensure molecular testing results are documented to support targeted therapy coding.

Pulmonology

Documentation Requirements

Pulmonary function tests, imaging results, and clinical notes on symptoms.

Common Clinical Scenarios

Patients presenting with respiratory symptoms and imaging suggestive of lung malignancy.

Billing Considerations

Document smoking history and environmental exposures to support risk factor assessment.

Coding Guidelines

Inclusion Criteria

Use C34.90 When
  • Follow official ICD
  • CM coding guidelines, ensuring that the code is used only when the specific site of the neoplasm cannot be determined
  • Document all relevant clinical findings and staging information

Exclusion Criteria

Do NOT use C34.90 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

32405CPT Code

Video-assisted thoracoscopic lobectomy

Clinical Scenario

Used for surgical treatment of lung cancer when the site is determined.

Documentation Requirements

Operative reports detailing the procedure and findings.

Specialty Considerations

Oncology specialists should ensure accurate coding based on the surgical site.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of lung cancers, but C34.90 remains a necessary code for cases where the site is not specified. It emphasizes the need for thorough documentation to avoid ambiguity.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of lung cancers, but C34.90 remains a necessary code for cases where the site is not specified. It emphasizes the need for thorough documentation to avoid ambiguity.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more specific coding of lung cancers, but C34.90 remains a necessary code for cases where the site is not specified. It emphasizes the need for thorough documentation to avoid ambiguity.

Resources

Clinical References

  • •
    American Cancer Society - Lung Cancer

Coding & Billing References

  • •
    American Cancer Society - Lung Cancer

Frequently Asked Questions

When should C34.90 be used?

C34.90 should be used when a malignant neoplasm of the lung or bronchus is diagnosed, but the specific site cannot be determined. It is essential to document the reasons for using this unspecified code.