ICD-10 Code C84.17 – Sézary disease, spleen (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C84.17 – Sézary disease, spleen
What it is
C84.17 identifies Sézary disease involving the spleen. Use it when documentation specifies splenic involvement as part of this cutaneous T-cell lymphoma.
Clinical signs
Clinical features vary; refer to documentation. Sézary disease commonly presents with diffuse skin findings, generalized lymphadenopathy, and circulating malignant T cells, with splenic involvement noted when present.
When to use this code
Use this code when the provider documents Sézary disease with spleen involvement, or when the spleen is named as the affected site in the diagnosis. It supports site-specific coding for this lymphoma. If the record only says Sézary disease without an anatomic site, check documentation before assigning C84.17.
Do not use for
Do not use it for Sézary disease without confirmed splenic involvement. Do not apply it to other cutaneous lymphomas or nonspecific splenomegaly.
Coding tip
Verify both the lymphoma type and the documented site; C84.17 is only appropriate when the spleen is explicitly identified.