Anaplastic large cell lymphoma, ALK-negative, unsp site

This code identifies a specific type of non-Hodgkin lymphoma characterized by large, anaplastic cells that do not express the anaplastic lymphoma kinase (ALK) protein. It is an aggressive malignancy originating from T-cells or, less commonly, NK-cells, and can affect various lymph nodes and extranodal sites.

Assign this code when documentation explicitly states a diagnosis of anaplastic large cell lymphoma that has been confirmed as ALK-negative. This diagnosis typically follows biopsy and immunohistochemical staining to determine ALK status. Use this code when the primary site of involvement is not specified.

• Ensure documentation clearly specifies "ALK-negative" to differentiate from ALK-positive variants.
• Avoid using this code if the ALK status is unknown or if the lymphoma is definitively ALK-positive (e.g., C84.6-).
• If a specific primary site is documented, use the more precise site-specific code (e.g., C84.71-C84.79).