ICD-10 Code C57.4 – Malignant neoplasm of uterine adnexa, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C57.4 – Malignant neoplasm of uterine adnexa, unspecified
What it is
C57.4 identifies a malignant neoplasm arising in the uterine adnexa, with the site not further specified. Use it when the record confirms cancer in the adnexal region but does not name a more exact structure.
Clinical signs
Clinical features vary; refer to documentation. Patients may present with a pelvic or adnexal mass, pain, bloating, abnormal bleeding, or findings from imaging or pathology that confirm malignancy.
When to use this code
Use this code when the provider documents a primary malignant tumor of the uterine adnexa and no more specific site is stated. It also fits cases where pathology or imaging supports malignancy, but the exact adnexal structure remains unspecified. Check documentation if the record suggests a different gynecologic site.
Do not use for
Do not use C57.4 for benign adnexal masses, ovarian cysts, or malignant neoplasms with a clearly documented more specific site. If the cancer is metastatic rather than primary, code the documented primary site instead.
Coding tip
Query for the exact adnexal site before assigning C57.4, because a more specific malignancy code may be available.