ICD-10 Code C51.8 – Malignant neoplasm of overlapping sites of vulva (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C51.8 – Malignant neoplasm of overlapping sites of vulva
What it is
This code identifies a malignant tumor of the vulva that spans more than one anatomic site and cannot be assigned to a single vulvar subsite. Use it when the documentation states overlapping involvement.
Clinical signs
Clinical features vary; refer to documentation. Vulvar cancer may present with a visible lesion, mass, ulceration, itching, pain, bleeding, or local irritation, but the coded diagnosis should match the documented site.
When to use this code
Use C51.8 when the provider documents vulvar malignancy involving overlapping regions, such as a lesion crossing subsite boundaries. It is appropriate when the record clearly indicates the cancer is not confined to one specific vulvar site. Check documentation if the anatomic location is vague.
Do not use for
Do not use this code for benign vulvar lesions, dysplasia, or malignancies limited to a single, clearly documented vulvar subsite. If the chart does not specify overlapping sites, select the more precise code or check documentation.
Coding tip
Confirm the exact vulvar site in the pathology or operative note before assigning C51.8.