Anaplastic large cell lymphoma, ALK-positive, spleen

This code signifies a rare and aggressive form of non-Hodgkin lymphoma characterized by large, anaplastic lymphocytes that test positive for the anaplastic lymphoma kinase (ALK) protein. Specifically, this diagnosis indicates the primary site of involvement is the spleen.

Apply this code when documentation confirms a pathological diagnosis of anaplastic large cell lymphoma, ALK-positive, with clear evidence of splenic involvement. This typically follows biopsy and immunohistochemical staining confirming ALK positivity.

• Ensure documentation explicitly states "ALK-positive" to differentiate from ALK-negative anaplastic large cell lymphoma.
• Verify the primary site of involvement is the spleen; do not use if other sites are primary or if splenic involvement is secondary.
• Sequence this code as the primary diagnosis when it is the reason for the encounter or treatment.