C51.9
BillableMalignant neoplasm of vulva, unspecified
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 of the vulva (external female genitalia) where the specific location is not documented or involves multiple areas.
Coding Tips
- •Use this code only when the specific site within the vulva cannot be determined from documentation
- •Query the provider if more specific anatomical location is available to assign a more precise code
Clinical Significance
Malignant neoplasm of vulva, unspecified, is the least specific vulvar cancer code and should be used only when the specific anatomical subsite cannot be determined from documentation. Vulvar cancer pathology reports typically identify the specific structure involved, making this code a documentation improvement opportunity in most cases.
Documentation Requirements
- ✓Confirmed malignancy of the vulva
- ✓Documentation explaining why a more specific subsite cannot be determined
- ✓Histological type and grade
- ✓TNM staging
- ✓Evidence of record review for more specific site information
- ✓Provider query documentation if subsite is missing
Commonly Confused Codes
C51.0 — Labium majus; use when the outer labia is specifically involvedC51.1 — Labium minus; use when the inner labia is specifically involvedC51.8 — Overlapping sites of vulva; use when multiple specific structures are involvedD07.1 — Carcinoma in situ of vulva; preinvasive disease, not invasive cancer
Code Hierarchy
└C51Malignant neoplasm of vulva└C51.9Malignant neoplasm of vulva, unspecified
└C51.9Malignant neoplasm of vulva, unspecified