Other mature T/NK-cell lymphomas, spleen

This code signifies a diagnosis of a mature T-cell or NK-cell lymphoma that is not otherwise specified as a more specific subtype, and where the primary or significant involvement is within the spleen. These are aggressive lymphoid malignancies originating from mature T-lymphocytes or natural killer cells.

Use this code when documentation confirms a diagnosis of a mature T/NK-cell lymphoma with splenic involvement, and the specific subtype (e.g., hepatosplenic T-cell lymphoma, enteropathy-associated T-cell lymphoma) is not identified or is explicitly ruled out. This applies when the pathology report indicates a mature T/NK-cell lymphoma, and imaging or clinical findings confirm splenic involvement, but a more precise ICD-10-CM code for a specific subtype is unavailable.

• Ensure documentation clearly states "other" or "unspecified" mature T/NK-cell lymphoma with splenic involvement to support this code.
• Do not use this code if a more specific mature T/NK-cell lymphoma subtype (e.g., C84.0-C84.8) is documented, even with splenic involvement.
• Sequence this code as the primary diagnosis when it is the reason for the encounter, followed by any associated signs, symptoms, or complications.