ICD-10 Code D39.1 – Neoplasm of uncertain behavior of ovary (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D39.1 – Neoplasm of uncertain behavior of ovary
What it is
D39.1 identifies an ovarian mass or growth whose behavior cannot be determined as clearly benign or malignant. Use it when the pathology or clinical record documents uncertain behavior.
Clinical signs
Clinical features vary; refer to documentation. Patients may have an adnexal mass, pelvic pain, bloating, or incidental imaging findings, but these findings alone do not establish the code.
When to use this code
Use D39.1 when the provider documents an ovarian neoplasm of uncertain behavior, borderline tumor, or similar wording. It also fits when pathology confirms uncertain biologic behavior and the ovary is the site. If the record is unclear, check documentation before assigning the code.
Do not use for
Do not use this code for clearly benign ovarian cysts or for malignant ovarian tumors. If the diagnosis states a different ovarian lesion or the site is unspecified, code the documented condition instead.
Coding tip
Code from the pathology or final provider diagnosis, and verify laterality or site details only if they are documented.