ICD-10 Code C51 – Malignant neoplasm of vulva (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C51 – Malignant neoplasm of vulva
What it is
C51 identifies a malignant tumor arising in the vulva. Use it when the record documents primary vulvar cancer, not a lesion of uncertain behavior or a metastasis from another site.
Clinical signs
Clinical features may include a vulvar mass, ulcer, itching, pain, bleeding, or visible skin changes. Diagnosis is confirmed by pathology; if details are unclear, check documentation.
When to use this code
Use C51 when the provider documents malignant neoplasm of the vulva, including a specified vulvar subsite if no more detailed code is given. Apply it for confirmed primary vulvar cancer in the assessment, problem list, or pathology report. If the note only says “vulvar lesion,” do not assume malignancy.
Do not use for
Do not use C51 for benign vulvar lesions, dysplasia, or carcinoma in situ unless the record specifically supports invasive malignancy. Also avoid it for metastatic disease to the vulva; code the primary site instead.
Coding tip
Check the pathology and provider assessment for the exact vulvar site and whether the cancer is primary or secondary.