Abstract
Aggressive natural killer cell leukemia (ANKL) is a disease entity within the spectrum of lymphoproliferative syndromes of NK cells. It is rare, preferentially affecting Asiatic people. It has been very rarely reported in the African population; hence the interest of our case. Our study involved a 19-year old female patient of Moroccan origin presenting with acute-onset bone marrow failure syndrome associated with tumor syndrome. The diagnosis of natural killer cell leukemia was retained based on microscopic and immunophenotypic study of the bone marrow. Patient's outcome was fatal; she died within 2 months of diagnosis due to septic shock. Patients with ANKL have a worse prognosis and the median survival time following diagnosis is, on average, two months. In the absence of a prospective study, no therapeutic guidelines have been developed.