ICD-10-CM Code for Left-Sided Hormone Receptor-Positive Breast Cancer
The ICD-10-CM code for left-sided hormone receptor-positive breast cancer is C50.912 (Malignant neoplasm of unspecified site of left female breast) or a more specific code from the C50.x11-C50.x12 series if the exact quadrant or location within the left breast is known.
Code Structure and Selection
The ICD-10-CM coding system for breast cancer follows this pattern:
- C50.xxx = Malignant neoplasm of breast
- The fourth character specifies the anatomic location (e.g., 0 = nipple, 1 = central portion, 2 = upper-inner quadrant, 3 = lower-inner quadrant, 4 = upper-outer quadrant, 5 = lower-outer quadrant, 8 = overlapping sites, 9 = unspecified)
- The fifth character indicates laterality:
- 1 = right breast
- 2 = left breast
- 9 = unspecified side
Specific Left Breast Codes:
- C50.011 = Malignant neoplasm of nipple and areola, left female breast
- C50.112 = Malignant neoplasm of central portion of left female breast
- C50.212 = Malignant neoplasm of upper-inner quadrant of left female breast
- C50.312 = Malignant neoplasm of lower-inner quadrant of left female breast
- C50.412 = Malignant neoplasm of upper-outer quadrant of left female breast
- C50.512 = Malignant neoplasm of lower-outer quadrant of left female breast
- C50.812 = Malignant neoplasm of overlapping sites of left female breast
- C50.912 = Malignant neoplasm of unspecified site of left female breast
Important Coding Considerations
The ICD-10-CM code does NOT capture hormone receptor status directly. The code identifies the anatomic location and laterality of the breast cancer only. Hormone receptor-positive status (ER+, PR+, or both) is documented separately in the medical record through pathology reports and immunohistochemistry results 1.
Key Points:
- Laterality is built into ICD-10-CM codes 2, which is an improvement over ICD-9-CM
- Use the most specific anatomic code available based on imaging and pathology documentation
- If the exact quadrant is unknown, use C50.912 for left breast, unspecified site
- Hormone receptor status should be documented separately in clinical notes and pathology reports, not through the ICD-10 code itself
Clinical Documentation Requirements:
For accurate coding, ensure documentation includes:
- Laterality (left breast)
- Specific anatomic location within the breast (quadrant, nipple, central)
- Hormone receptor status (ER and PR expression levels) in pathology reports 1
- HER2 status for complete characterization
The hormone receptor-positive designation is critical for treatment planning 1, 3 but is captured through clinical documentation and pathology coding systems, not the primary ICD-10-CM diagnosis code.