ICD-10 Code D40.9 – Neoplasm of Uncertain Behavior of Male Genital Organ, Unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D40.9 – Neoplasm of uncertain behavior of male genital organ, unspecified
What it is
This code identifies a growth in a male genital organ whose behavior is uncertain, meaning the pathology does not clearly show benign or malignant features. Use it when the specific organ is not documented.
Clinical signs
Clinical features vary; refer to documentation. You may see a mass, abnormal imaging, or a lesion found during exam, but the key point is that the neoplasm’s behavior remains uncertain.
When to use this code
Use D40.9 when the provider documents an uncertain-behavior neoplasm involving a male genital organ but does not specify the site. It also fits when the record confirms the diagnosis yet the exact organ is not named. Check documentation if the pathology report or note gives a more specific organ.
Do not use for
Do not use this code for clearly benign or malignant tumors, or when the record identifies a specific male genital organ with a more precise code. Do not guess the site.
Coding tip
Query for the exact organ and behavior when the note says “mass” or “lesion” without a final diagnosis.