Mature T/NK-cell lymphomas, unspecified, unspecified site

This code identifies a malignant neoplasm originating from mature T-lymphocytes or natural killer (NK) cells, where the specific subtype of lymphoma has not been determined. It represents a broad category of non-Hodgkin lymphomas characterized by the proliferation of these specific immune cells.

Assign this code when the medical record clearly indicates a diagnosis of mature T-cell or NK-cell lymphoma, but the pathologist or clinician has not yet specified the exact subtype (e.g., peripheral T-cell lymphoma, angioimmunoblastic T-cell lymphoma). This is often used as a provisional diagnosis or when further diagnostic workup is pending or inconclusive.

• Avoid using this code if a more specific subtype of mature T/NK-cell lymphoma is documented.
• Ensure documentation supports the "unspecified site" component; if a primary site is known, a more specific code should be sought.
• Query the provider for clarification on the specific lymphoma subtype and primary site if possible, to allow for more precise coding.