ICD-10 Code C90.2 – Extramedullary Plasmacytoma (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C90.2 – Extramedullary plasmacytoma
What it is
Extramedullary plasmacytoma is a localized tumor made of abnormal plasma cells outside the bone marrow. It usually involves soft tissues such as the upper airway or other non-bony sites.
Clinical signs
Clinical features vary; refer to documentation. Common findings include a solitary mass, local swelling, or symptoms from compression depending on the site, with pathology confirming plasma cell neoplasm.
When to use this code
Use C90.2 when the provider documents extramedullary plasmacytoma or a solitary extramedullary plasma cell tumor. Code it when the lesion is outside the bone marrow and the record supports a localized plasma cell neoplasm. Check documentation for site and whether disease is solitary.
Do not use for
Do not use this code for multiple myeloma, plasmacytoma of bone, or nonspecific plasma cell disorders. If the documentation only says “plasma cell tumor” without location, check documentation.
Coding tip
Verify that the record clearly states an extramedullary site before assigning C90.2.