ICD-10 Code D43.2 – Neoplasm of uncertain behavior of brain, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D43.2 – Neoplasm of uncertain behavior of brain, unspecified
What it is
This code identifies a brain neoplasm whose behavior is uncertain, meaning the record does not clearly show whether it is benign or malignant. Use it when the documentation specifically states the brain lesion is of uncertain behavior and the site is unspecified.
Clinical signs
Clinical features vary; refer to documentation. Brain masses may be associated with headaches, seizures, focal neurologic deficits, or signs of increased intracranial pressure, but the diagnosis here depends on documented pathology or clinician assessment.
When to use this code
Use D43.2 when the provider documents a neoplasm of uncertain behavior involving the brain and does not identify a more specific intracranial site. It is appropriate for confirmed uncertain-behavior tumors, pathology reports, or specialist notes that support this wording. If the record names a different site or behavior, code that information instead.
Do not use for
Do not use this code for benign, malignant, or metastatic brain tumors with a clearly defined behavior. Also avoid it when the documentation only says “brain mass,” “lesion,” or “tumor” without stating uncertain behavior.
Coding tip
Check the exact pathology or provider wording before assigning D43.2.