Anaplastic large cell lymphoma, ALK-negative, breast

This code identifies a specific subtype of non-Hodgkin lymphoma characterized by the proliferation of large, anaplastic T-cells or null cells that lack the anaplastic lymphoma kinase (ALK) protein expression. This particular diagnosis specifies the primary site of involvement as the breast.

Assign this code when documentation confirms a diagnosis of ALK-negative anaplastic large cell lymphoma with primary manifestation in the breast. This diagnosis typically requires histopathological confirmation and immunohistochemical staining to determine ALK status.

• Ensure documentation explicitly states "ALK-negative" and "breast" as the primary site.
• Do not confuse with ALK-positive anaplastic large cell lymphoma, which has a different code.
• Code any associated signs, symptoms, or complications as secondary diagnoses.