ICD-10-CM Code for Stage 3b Right-Sided Triple-Negative Breast Cancer
The ICD-10-CM code for stage 3b right-sided triple-negative breast cancer is C50.911 (malignant neoplasm of unspecified site of right female breast) combined with the appropriate stage code.
Primary Diagnosis Code
- C50.911 is used when the specific quadrant or site within the right breast is not documented 1
- If the specific location within the right breast is known, use the more specific code:
- C50.111 for upper-outer quadrant of right breast
- C50.211 for upper-inner quadrant of right breast
- C50.311 for lower-inner quadrant of right breast
- C50.411 for lower-outer quadrant of right breast
- C50.811 for overlapping sites of right breast 1
Additional Required Codes
- Stage 3b designation requires documentation that the tumor has extended to the chest wall and/or skin with ulceration or satellite nodules (T4b), or both chest wall extension and skin involvement (T4c), with any nodal involvement 1
- Triple-negative status should be documented separately using morphology codes, though this is typically captured in the pathology report rather than as a separate ICD-10 code 1
Clinical Context
- Stage 3b TNBC is defined by T4b (skin ulceration/satellite nodules/edema including peau d'orange) with any N stage, or any T with N3 (≥10 axillary nodes or infraclavicular/supraclavicular nodes) 1
- Triple-negative status (ER-negative, PR-negative, HER2-negative) represents approximately 10-20% of invasive breast cancers and carries a poorer prognosis than hormone receptor-positive subtypes 1
- This aggressive subtype is more common in premenopausal women and women of African descent 1
Documentation Requirements
- Ensure pathology reports clearly document ER, PR, and HER2 status as negative to support the triple-negative designation 1
- Clinical staging should document the extent of chest wall or skin involvement to justify the stage 3b classification 1
- Laterality (right-sided) must be explicitly documented to use the correct code 1