ICD-10 Code D42 – Neoplasm of uncertain behavior of meninges (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D42 – Neoplasm of uncertain behavior of meninges
What it is
D42 identifies a tumor of the meninges whose behavior is uncertain, meaning the pathology cannot clearly label it benign or malignant. Use it when documentation supports an uncertain neoplasm involving the meninges.
Clinical signs
Clinical features vary; refer to documentation. Patients may present with symptoms related to a meningeal mass or be diagnosed after imaging and pathology review.
When to use this code
Use D42 when the provider documents a neoplasm of uncertain behavior arising from the meninges, including after biopsy or surgical pathology. Code it when the record does not support a benign or malignant designation. Check documentation if the site or behavior is unclear.
Do not use for
Do not use D42 for clearly benign meningeal tumors or for malignant neoplasms of the meninges. If the record identifies a different primary site or behavior, code that diagnosis instead.
Coding tip
Confirm the exact anatomic site and the stated behavior in the pathology or provider note before assigning D42.