ICD-10 Code C57.00 – Malignant neoplasm of unspecified fallopian tube (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C57.00 – Malignant neoplasm of unspecified fallopian tube
What it is
C57.00 identifies a malignant tumor in a fallopian tube when the site is not further specified. Use it when documentation confirms fallopian tube cancer but does not name the left or right side.
Clinical signs
Clinical features vary; refer to documentation. Patients may present with pelvic pain, abnormal vaginal bleeding, or an adnexal mass, but diagnosis depends on pathology or other confirmed clinical evidence.
When to use this code
Use C57.00 when the record states primary malignancy of the fallopian tube and laterality is not documented. It also applies when the provider documents a fallopian tube carcinoma without specifying which tube. If the note later identifies the side, code to the more specific option.
Do not use for
Do not use this code for benign fallopian tube lesions, metastatic disease to the tube, or cancers documented as originating in another gynecologic site. Check documentation if the primary site is unclear.
Coding tip
Query the provider when the report says “fallopian tube cancer” but omits laterality or primary site details.