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ICD-10 Guide
ICD-10 CodesC18.2

C18.2

Billable

Malignant neoplasm of ascending colon

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

Code Description

ICD-10 C18.2 is a billable code used to indicate a diagnosis of malignant neoplasm of ascending colon.

Key Diagnostic Point:

C18.2 refers to a malignant neoplasm located in the ascending colon, which is the first part of the large intestine. Colorectal cancer, including cancers of the ascending colon, is a significant health concern and is often diagnosed through screening methods such as colonoscopy. The disease can present with various symptoms, including abdominal pain, changes in bowel habits, and unexplained weight loss. Staging of colorectal cancer is crucial for determining the extent of the disease and guiding treatment options, with stages ranging from I (localized) to IV (metastatic). The presence of microsatellite instability (MSI) can indicate a specific subtype of colorectal cancer that may respond differently to treatment. Surgical approaches for C18.2 typically involve resection of the affected segment of the colon, often accompanied by lymphadenectomy to assess for regional spread. Adjuvant therapies, including chemotherapy and targeted therapies, may also be indicated based on the tumor's characteristics and staging.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variability in staging and treatment protocols
  • Need for precise documentation of tumor location and characteristics
  • Differentiation from benign conditions and other malignancies
  • Potential for multiple co-existing conditions affecting coding

Audit Risk Factors

  • Inadequate documentation of tumor staging
  • Failure to document the presence of microsatellite instability
  • Incorrect coding of surgical procedures performed
  • Misidentification of the primary site of the tumor

Specialty Focus

Medical Specialties

Oncology

Documentation Requirements

Detailed pathology reports, staging information, and treatment plans.

Common Clinical Scenarios

Initial diagnosis of colorectal cancer, treatment planning, and follow-up care.

Billing Considerations

Ensure accurate documentation of tumor markers and response to treatment.

Gastroenterology

Documentation Requirements

Endoscopy reports, biopsy results, and imaging studies.

Common Clinical Scenarios

Screening colonoscopies, polypectomy, and management of gastrointestinal symptoms.

Billing Considerations

Document findings related to the ascending colon and any interventions performed.

Coding Guidelines

Inclusion Criteria

Use C18.2 When
  • Follow the official ICD
  • CM coding guidelines, ensuring accurate documentation of the primary site, staging, and any relevant treatment details
  • Include any relevant modifiers for surgical procedures

Exclusion Criteria

Do NOT use C18.2 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

44140CPT Code

Colectomy, partial, with anastomosis

Clinical Scenario

Used when a patient undergoes surgical resection of the ascending colon due to malignancy.

Documentation Requirements

Operative report detailing the procedure performed and findings.

Specialty Considerations

Oncology and surgery must coordinate documentation for accurate coding.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of colorectal cancers, improving the accuracy of data collection and reimbursement processes. C18.2 provides a clear distinction for malignant neoplasms of the ascending colon, facilitating better tracking of treatment outcomes.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of colorectal cancers, improving the accuracy of data collection and reimbursement processes. C18.2 provides a clear distinction for malignant neoplasms of the ascending colon, facilitating better tracking of treatment outcomes.

Reimbursement & Billing Impact

reimbursement processes. C18.2 provides a clear distinction for malignant neoplasms of the ascending colon, facilitating better tracking of treatment outcomes.

Resources

Clinical References

  • •
    American Cancer Society - Colorectal Cancer

Coding & Billing References

  • •
    American Cancer Society - Colorectal Cancer

Frequently Asked Questions

What is the significance of microsatellite instability in colorectal cancer?

Microsatellite instability (MSI) is a condition of genetic hypermutability that can affect treatment decisions. Tumors with MSI may respond better to certain immunotherapies, making it crucial to document this finding in cases of C18.2.