Small cell B-cell lymphoma, lymph nodes of multiple sites

This code identifies a rare, aggressive subtype of non-Hodgkin lymphoma characterized by small B-lymphocytes, affecting multiple lymph node regions throughout the body. It signifies a disseminated presentation of this specific B-cell malignancy.

Assign this code when documentation confirms a diagnosis of small cell B-cell lymphoma with involvement of lymph nodes in more than one anatomical region. Supporting documentation should clearly specify the B-cell lineage and the multifocal nodal involvement, often confirmed by biopsy and imaging studies.

• Differentiate from other small B-cell lymphomas (e.g., chronic lymphocytic leukemia/small lymphocytic lymphoma) which have distinct codes.
• Ensure the "multiple sites" aspect is clearly documented; single site involvement would necessitate a more specific anatomical code.
• This code is for the primary diagnosis; sequence appropriately with any associated complications or treatments.