ICD-10 Code C84.Z6 – Other mature T/NK-cell lymphomas, intrapelvic lymph nodes (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C84.Z6 – Other mature T/NK-cell lymphomas, intrapelvic lymph nodes
What it is
This code identifies a mature T-cell or natural killer (NK-cell) lymphoma involving intrapelvic lymph nodes. Use it when the record specifies this lymphoma type and pelvic nodal location.
Clinical signs
Clinical features vary; refer to documentation. Patients may have lymph node enlargement, pelvic mass effect, or systemic lymphoma findings, but the diagnosis should be supported by pathology or specialist assessment.
When to use this code
Use this code when the provider documents other mature T/NK-cell lymphoma in intrapelvic lymph nodes, including a confirmed nodal site within the pelvis. It is appropriate for staging, oncology follow-up, or encounter coding when that site is the focus of care. Check documentation if the record only says lymphoma without a specified subtype or location.
Do not use for
Do not use this code for B-cell lymphomas, Hodgkin lymphoma, or unspecified non-Hodgkin lymphoma. Also avoid it when the lymphoma site is not documented as intrapelvic lymph nodes.
Coding tip
Confirm both the mature T/NK-cell subtype and the pelvic nodal site in the pathology or oncology note before assigning C84.Z6.