C50.312

Billable

Malignant neoplasm of lower-inner quadrant of left female breast

HCC Category Mapping

V28HCC 23 — Melanoma and Other Skin Cancers

0.251

V24HCC 12 — Breast, Prostate, and Other Cancers and Tumors

0.150

ESRDHCC 12 — Breast, Prostate, and Other Cancers and Tumors

0.000

RxHCCHCC 22 — Cancer, Other Specified Sites

0.000

What This Code Means

Cancer that starts in the lower-inner area of the left breast in a female patient.

Coding Tips

•Confirm left breast laterality is documented to differentiate from C50.311
•Lower-inner quadrant cancers may have different clinical implications; ensure accurate quadrant documentation

Clinical Significance

Malignant neoplasm of the lower-inner quadrant of left female breast represents invasive breast cancer requiring staging, treatment planning, and ongoing surveillance. Breast cancer is risk-adjusted because it demands significant healthcare resources including surgery, radiation, chemotherapy, hormonal therapy, and long-term monitoring.

Documentation Requirements

✓Pathologic confirmation of invasive malignancy (biopsy with histologic type — ductal, lobular, etc.)
✓Laterality: left breast
✓Gender documented as female to support gender-specific code selection
✓Quadrant or subsite location: lower-inner quadrant
✓Tumor size (T stage) and grade
✓Lymph node status (N stage) — axillary, sentinel node biopsy results
✓Estrogen receptor, progesterone receptor, and HER2 status
✓Stage grouping (I-IV)
✓Current treatment status (active treatment, hormonal therapy, surveillance)

Commonly Confused Codes

C50.311 — Lower-inner quadrant of right female breast; verify laterality C50.319 — Lower-inner quadrant unspecified female; use only when laterality unknown C50.322 — Same laterality but male breast; verify patient gender C50.211-C50.219 — Upper-inner quadrant; same medial orientation but upper position — verify upper vs. lower C50.511-C50.519 — Lower-outer quadrant; same lower position but lateral vs. medial orientation C50.111-C50.119 — Central portion; adjacent to lower-inner but anatomically distinct

Code Hierarchy

└C50Malignant neoplasm of breast └C50.3Malignant neoplasm of lower-inner quadrant of breast └C50.31Malignant neoplasm of lower-inner quadrant of breast, female └C50.312Malignant neoplasm of lower-inner quadrant of left female breast

└C50.312Malignant neoplasm of lower-inner quadrant of left female breast