ICD-10 Code D39.9 – Neoplasm of uncertain behavior of female genital organ, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D39.9 – Neoplasm of uncertain behavior of female genital organ, unspecified
What it is
D39.9 identifies a neoplasm in a female genital organ whose behavior is uncertain, meaning the pathology cannot clearly classify it as benign or malignant. Use this unspecified code when the exact site is not documented.
Clinical signs
Clinical features vary; refer to documentation. Findings may include an adnexal or pelvic mass, abnormal bleeding, pain, or an incidental imaging or pathology report describing uncertain behavior.
When to use this code
Use D39.9 when the provider documents an uncertain-behavior neoplasm in a female reproductive organ but does not specify the exact organ. It is appropriate when the record supports a neoplasm diagnosis and site detail is missing. If the documentation later identifies the organ, code the more specific option.
Do not use for
Do not use this code for clearly benign or malignant tumors, or when the site is documented more specifically. Check documentation if the report only describes a cyst, mass, or lesion without confirming neoplasm.
Coding tip
Query for the exact anatomic site whenever possible before assigning the unspecified code.