Mantle cell lymphoma, lymph nodes of axilla and upper limb

This code signifies a specific type of non-Hodgkin lymphoma, mantle cell lymphoma, affecting the lymph nodes located in the axilla (armpit) and/or upper limb. It represents a malignant proliferation of small to medium-sized lymphocytes with cleaved nuclei, typically expressing CD5 and cyclin D1.

Use this code when documentation clearly indicates a diagnosis of mantle cell lymphoma with confirmed involvement of lymph nodes in the axillary region or upper arm. This diagnosis is typically established through biopsy and immunohistochemical staining.

• Ensure the pathology report specifically identifies "mantle cell lymphoma" and specifies involvement of axillary or upper limb lymph nodes.
• Distinguish from other non-Hodgkin lymphomas affecting these sites; precise histological subtype is crucial.
• Sequence this code as the primary diagnosis when it is the reason for the encounter, or as a secondary diagnosis if it's an existing condition impacting treatment.