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ICD-10 Guide
ICD-10 CodesD05.9

D05.9

Billable

Unspecified type of carcinoma in situ of breast

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

Code Description

ICD-10 D05.9 is a billable code used to indicate a diagnosis of unspecified type of carcinoma in situ of breast.

Key Diagnostic Point:

Carcinoma in situ (CIS) of the breast refers to a group of abnormal cells that are found in the lining of the breast ducts or lobules. These cells have the potential to become invasive cancer but are currently confined to their original location. The term 'unspecified type' indicates that the specific subtype of carcinoma in situ, such as ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS), has not been determined. Patients diagnosed with D05.9 may undergo various surveillance protocols, including regular mammograms and clinical breast exams, to monitor for any signs of progression to invasive cancer. The risk of progression varies based on factors such as the size of the lesion, histological features, and patient age. While many patients with DCIS may not progress to invasive disease, those with LCIS have a higher risk of developing breast cancer in either breast over time. Therefore, individualized risk assessment and management strategies are essential for optimal patient outcomes.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variability in documentation of carcinoma types
  • Need for precise histological details
  • Differentiation between in situ and invasive cancers
  • Potential for multiple concurrent breast conditions

Audit Risk Factors

  • Inadequate documentation of histological type
  • Failure to document surveillance protocols
  • Misclassification of in situ versus invasive carcinoma
  • Lack of follow-up documentation

Specialty Focus

Medical Specialties

Oncology

Documentation Requirements

Detailed pathology reports, treatment plans, and follow-up care notes.

Common Clinical Scenarios

Diagnosis of carcinoma in situ, treatment planning, and monitoring for progression.

Billing Considerations

Ensure accurate documentation of tumor characteristics and patient risk factors.

Radiology

Documentation Requirements

Imaging reports, findings from mammograms, and breast ultrasounds.

Common Clinical Scenarios

Screening mammograms showing suspicious findings, follow-up imaging for known carcinoma in situ.

Billing Considerations

Clear documentation of imaging findings and recommendations for further evaluation.

Coding Guidelines

Inclusion Criteria

Use D05.9 When
  • According to ICD
  • CM guidelines, D05
  • 9 should be used when the specific type of carcinoma in situ is not documented
  • Coders should ensure that the diagnosis is confirmed by pathology and that the documentation supports the diagnosis of carcinoma in situ

Exclusion Criteria

Do NOT use D05.9 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

19301CPT Code

Mastectomy, partial (lumpectomy)

Clinical Scenario

Used when a patient with D05.9 undergoes surgical intervention for carcinoma in situ.

Documentation Requirements

Operative report detailing the procedure and findings.

Specialty Considerations

Oncologists should ensure that the diagnosis is clearly linked to the surgical procedure.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of breast conditions, including carcinoma in situ. D05.9 provides a way to capture cases where the specific type is not documented, but it also 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 breast conditions, including carcinoma in situ. D05.9 provides a way to capture cases where the specific type is not documented, but it also emphasizes the need for thorough documentation to avoid ambiguity.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more specific coding of breast conditions, including carcinoma in situ. D05.9 provides a way to capture cases where the specific type is not documented, but it also emphasizes the need for thorough documentation to avoid ambiguity.

Resources

Clinical References

  • •
    American Cancer Society - Breast Cancer

Coding & Billing References

  • •
    American Cancer Society - Breast Cancer

Frequently Asked Questions

What does carcinoma in situ mean?

Carcinoma in situ refers to abnormal cells that are localized and have not invaded surrounding tissues. It is considered a non-invasive form of cancer.

How is carcinoma in situ treated?

Treatment options may include surgery, radiation therapy, and hormone therapy, depending on the specific type and individual patient factors.

What is the risk of progression for carcinoma in situ?

The risk of progression to invasive cancer varies based on the type of carcinoma in situ, with DCIS having a lower risk compared to LCIS, which increases the risk of developing breast cancer in either breast.