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v1.0.0
ICD-10 Guide
ICD-10 CodesChapter 2: NeoplasmsC80

C80

Billable

Malignant neoplasm without specification of site

Chapter 2:Neoplasms

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

Code Description

ICD-10 C80 is a billable code used to indicate a diagnosis of malignant neoplasm without specification of site.

Key Diagnostic Point:

C80 is used to classify malignant neoplasms when the primary site of the cancer is unknown or unspecified. This code is often applied in cases of metastatic disease where the origin of the cancer cannot be determined, which complicates treatment and management. Patients may present with symptoms related to metastases, such as pain, weight loss, or organ dysfunction, but without a clear primary tumor identified. Staging of the disease is critical, as it influences treatment decisions and prognosis. In many cases, imaging studies and biopsies may be performed to identify the primary site, but if these efforts are inconclusive, C80 is the appropriate code. Palliative care considerations are paramount for these patients, focusing on symptom management and quality of life, as the prognosis can be poor without a known primary site. Accurate coding is essential for appropriate reimbursement and to reflect the complexity of care provided.

Code Complexity Analysis

Complexity Rating: High

High Complexity

Complexity Factors

  • Difficulty in determining the primary site of malignancy
  • Need for comprehensive documentation of diagnostic efforts
  • Variability in treatment protocols based on staging
  • Potential for multiple metastatic sites complicating coding

Audit Risk Factors

  • Insufficient documentation of diagnostic efforts to identify primary site
  • Inconsistent staging information
  • Lack of clarity in treatment plans
  • Failure to document palliative care considerations

Specialty Focus

Medical Specialties

Oncology

Documentation Requirements

Detailed records of diagnostic imaging, pathology reports, and treatment plans.

Common Clinical Scenarios

Patients presenting with symptoms of metastatic disease without a known primary tumor.

Billing Considerations

Ensure thorough documentation of all diagnostic efforts and multidisciplinary consultations.

Palliative Care

Documentation Requirements

Comprehensive symptom management plans and discussions regarding goals of care.

Common Clinical Scenarios

Patients with advanced malignancies requiring symptom relief and end-of-life care.

Billing Considerations

Focus on quality of life and patient preferences in documentation.

Coding Guidelines

Inclusion Criteria

Use C80 When
  • According to ICD
  • 10 guidelines, C80 should be used when the primary site of the malignant neoplasm is not documented or cannot be determined
  • It is important to ensure that all efforts to identify the primary site are documented in the patient's medical record

Exclusion Criteria

Do NOT use C80 When
No specific exclusions found.

Related CPT Codes

99214CPT Code

Established patient office visit, level 4

Clinical Scenario

Used for follow-up visits for patients with unknown primary malignancies.

Documentation Requirements

Document the patient's history, examination findings, and treatment plan.

Specialty Considerations

Oncology specialists should ensure comprehensive documentation of cancer staging and treatment discussions.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has increased specificity in cancer coding, but C80 remains a critical code for cases where the primary site is unknown. It emphasizes the need for thorough documentation and clinical rationale.

ICD-9 vs ICD-10

The transition to ICD-10 has increased specificity in cancer coding, but C80 remains a critical code for cases where the primary site is unknown. It emphasizes the need for thorough documentation and clinical rationale.

Reimbursement & Billing Impact

The transition to ICD-10 has increased specificity in cancer coding, but C80 remains a critical code for cases where the primary site is unknown. It emphasizes the need for thorough documentation and clinical rationale.

Resources

Clinical References

  • •
    ICD-10-CM Official Guidelines for Coding and Reporting

Coding & Billing References

  • •
    ICD-10-CM Official Guidelines for Coding and Reporting

Frequently Asked Questions

When should C80 be used?

C80 should be used when a malignant neoplasm is present, but the primary site cannot be determined after appropriate diagnostic efforts.