C84: Mature T/NK-cell lymphomas

C84.7: Anaplastic large cell lymphoma, ALK-negative

Anaplastic large cell lymphoma, ALK-negative (ALK- ALCL) is a rare type of non-Hodgkin lymphoma, a cancer that starts in cells called lymphocytes, which are part of the body's immune system. The lymphoma cells of ALK- ALCL are characteristically large and anaplastic, indicating that they have lost the appearance and function of normal, mature cells. This particular type of lymphoma is labelled ALK-negative because it does not express the anaplastic lymphoma kinase (ALK) protein that is typically found in some other types of ALCL. It generally presents with symptoms like fever, weight loss, and night sweats. Lymph node enlargement may also be seen, usually in the neck, armpit or groin. It can affect individuals of any age, but is more common in adults and tends to be more aggressive compared to its ALK-positive counterpart. The disease progression varies widely among individuals and its cause remains unclear.