ICD-10 Code for Invasive Hormone Receptor-Positive Breast Cancer
The ICD-10 code for invasive hormone receptor-positive breast cancer is C50.x (where x specifies the anatomical location within the breast), combined with additional codes to specify hormone receptor status and laterality.
Primary Diagnostic Code Structure
The base code C50 represents malignant neoplasm of breast, with the fourth character specifying the exact anatomical site:
- C50.0 - Nipple and areola
- C50.1 - Central portion of breast
- C50.2 - Upper-inner quadrant
- C50.3 - Lower-inner quadrant
- C50.4 - Upper-outer quadrant
- C50.5 - Lower-outer quadrant
- C50.6 - Axillary tail
- C50.8 - Overlapping sites of breast
- C50.9 - Breast, unspecified
A fifth character is required to specify laterality:
- 1 = Right breast
- 2 = Left breast
- 9 = Unspecified side
Important Coding Considerations
For hormone receptor-positive status specifically, while the C50.x code captures the invasive breast cancer diagnosis, the hormone receptor positivity is typically documented through:
- Clinical documentation in the medical record
- Pathology reports showing ER/PR immunohistochemistry results
- Additional documentation codes if your system requires specification of receptor status
Clinical Context from Guidelines
According to current NCCN guidelines 1, hormone receptor-positive breast cancer is defined as:
- ER-positive: 1-100% ER immunohistochemistry staining
- PR-positive: 1-100% nuclear staining
- Any ER and/or PR-positive tumor is considered "HR-positive"
Common Pitfalls to Avoid
- Don't confuse with carcinoma in situ: ICD-9 code 233.0 was for carcinoma in situ 2; invasive disease requires the C50.x series
- Specify anatomical location: Using C50.9 (unspecified) should be avoided when the specific breast quadrant is known
- Document laterality: The fifth character is mandatory for complete coding
- Ensure "invasive" is documented: This distinguishes from in situ disease (D05.x codes)
Validation Note
Research demonstrates that ICD codes in primary position have high accuracy for identifying breast cancer cases, with positive predictive values ≥83% in most studies and sensitivity ≥80% 2. However, codes must be in primary position for optimal accuracy; secondary position codes have significantly lower accuracy.
Example complete code: C50.411 would represent malignant neoplasm of upper-outer quadrant of right female breast (invasive), with hormone receptor status documented separately in the clinical record.