ICD-10 Code C83.390 – Primary central nervous system lymphoma (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C83.390 – Primary central nervous system lymphoma
What it is
C83.390 identifies lymphoma that starts in the brain, spinal cord, leptomeninges, or eye structures within the central nervous system. Use it when documentation specifies a primary CNS lymphoma rather than lymphoma elsewhere with secondary spread.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include focal neurologic deficits, cognitive or behavioral changes, seizures, headaches, or visual symptoms, with imaging or biopsy supporting the diagnosis.
When to use this code
Use this code when the provider documents primary central nervous system lymphoma, including primary brain or spinal cord involvement. It also fits cases described as lymphoma confined to the CNS or ocular tissues as the primary site. If the record only says lymphoma with CNS metastasis, check documentation.
Do not use for
Do not use this code for lymphoma that began outside the CNS and later spread there. Check documentation if the record describes systemic lymphoma, secondary CNS involvement, or an unspecified lymphoma type.
Coding tip
Confirm the phrase “primary” and the anatomic site in the provider note before assigning C83.390.