C51.0
BillableMalignant neoplasm of labium majus
HCC Category Mapping
V28HCC 22 — Colorectal, Bladder, and Other Cancers
0.000V24HCC 11 — Colorectal, Bladder, and Other Cancers
0.306ESRDHCC 11 — Colorectal, Bladder, and Other Cancers
0.000What This Code Means
Cancer that starts in the larger outer folds of the female external genitalia (labia majora).
Coding Tips
- •Verify histology type (squamous cell carcinoma is most common) for additional specificity
- •Confirm laterality if documented (left, right, or bilateral) as this may affect staging
Clinical Significance
Malignant neoplasm of the labium majus is a vulvar cancer affecting the outer, larger folds of the female external genitalia. Vulvar cancer is relatively uncommon, accounting for approximately 5% of gynecological malignancies. It is strongly associated with Human Papillomavirus infection and chronic vulvar dermatoses such as lichen sclerosus.
Documentation Requirements
- ✓Specific anatomical site confirmed as labium majus (not labium minus or other vulvar structure)
- ✓Histological type (squamous cell carcinoma accounts for approximately 90%)
- ✓Tumor grade and TNM staging
- ✓Depth of invasion (critical for staging vulvar cancer)
- ✓Lymph node assessment — inguinofemoral node status
- ✓Human Papillomavirus status if documented
- ✓Laterality (right, left, or bilateral) when documented
Commonly Confused Codes
C51.1 — Malignant neoplasm of labium minus; different anatomical structure — labium majus is the outer fold, labium minus is the inner foldC51.9 — Malignant neoplasm of vulva, unspecified; use only when the specific vulvar structure is not documentedC51.8 — Overlapping sites of vulva; use when tumor spans multiple vulvar structuresD07.1 — Carcinoma in situ of vulva; preinvasive disease, not yet malignant invasion
Code Hierarchy
└C51Malignant neoplasm of vulva└C51.0Malignant neoplasm of labium majus
└C51.0Malignant neoplasm of labium majus