Other mature T/NK-cell lymphomas, unspecified site

This code represents a diagnosis of mature T-cell or natural killer (NK)-cell lymphomas that do not fit into more specific categories. These are aggressive non-Hodgkin lymphomas originating from mature T-lymphocytes or NK-cells, with the primary site of involvement not specified in the medical record.

Use this code when the pathology report confirms a mature T/NK-cell lymphoma, but the specific subtype (e.g., anaplastic large cell, peripheral T-cell, angioimmunoblastic) is not identified or documented. It is also appropriate when the primary anatomical site of the lymphoma is not clearly stated. Documentation should clearly indicate a diagnosis of "other" or "unspecified" mature T/NK-cell lymphoma.

• Do not use this code if a more specific subtype of mature T/NK-cell lymphoma is documented; always code to the highest level of specificity.
• If the primary site is known, use a more specific code from the C84 category that includes the site (e.g., C84.Z1 for lymph nodes, C84.Z2 for extranodal and solid organs).
• This code is for the diagnosis of lymphoma; do not confuse it with codes for symptoms or complications of the disease.