Anaplastic large cell lymphoma, ALK-pos, intrathorac nodes

This code identifies a specific type of non-Hodgkin lymphoma characterized by large, anaplastic cells that test positive for the anaplastic lymphoma kinase (ALK) protein. The disease is localized to the lymph nodes within the chest cavity. This is a distinct subtype with particular biological and clinical features.

Apply this code when documentation explicitly states a diagnosis of anaplastic large cell lymphoma that is ALK-positive and primarily affects the intrathoracic lymph nodes. Confirmation of ALK positivity, typically via immunohistochemistry or FISH, is crucial for accurate coding. This code is used for initial diagnosis, active treatment, and follow-up care for this specific lymphoma subtype.

• Ensure documentation specifies both "ALK-positive" and "intrathoracic lymph nodes" for this precise code.
• Do not use this code for ALK-negative anaplastic large cell lymphoma or for extranodal involvement.
• Sequence this code as the primary diagnosis when it is the reason for the encounter, followed by any associated complications or manifestations.