Aggressive Natural Killer Cell Leukemia in an Adolescent Patient: A Case Report and Literature Review

Abstract

Aggressive natural killer cell leukemia (ANKL) is a rare malignant tumor, especially uncommon in children. ANKL has very aggressive clinical course and bad prognosis and is usually caused by Epstein-Barr virus infection. ANKL often has clinical manifestations of hemophagocytic lymphohistiocytosis (HLH) and can be easily treated as HLH, which might complicate this aggressive disease. Here we report an ANKL in adolescent whose clinical presentation was highly aggressive and response to L-asparaginase containing chemotherapy was very bad. Early-onset Flow cytometry of peripheral blood and bone marrow help make the diagnosis.

Keywords: Epstein-Barr virus; aggressive natural killer cell leukemia; case report; children; hemophagocytic lymphohistiocytosis.

FIGURE 1

Wright-Giemsa stain of bone marrow (×1,000). (A) Hemophagocytosis in bone marrow smear. (B–D) Large granular variant lymphocytes in bone marrow smear and the proportion was 6%.

FIGURE 2

The flow cytometry detection of bone marrow revealed CD3–CD56+ cells counted for 55.67% of the lymphocytes, with HLA-DR+, CD2+, CD7 (dim)+, CD16+, CD38+, CD56+, and CD3–.

FIGURE 3

Axial magnetic resonance imaging of the brain in this ANKL patient. Axial T2-weighted (1B–3B) and fluid-attenuated inversion recovery (1C–3C) of brain showing white matter high signal at bilateral centrum ovale, periventricular areas, basal ganglia areas and pontine. Axial T1-weighted (2A) imaging and diffusion-weighted imaging (2D) shows high signal at areas of putamen and caudate nucleus head.

FIGURE 4

Typical laboratory indexes of blood and the drugs used for the patient from day of admitting, she died 55 days later. LDH, lactic dehydrogenase; ALY, atypical lymphocyte; WBC, white blood cell; DDI, D-Dimer; DEX, dexamethasone; MP, methylprednisolone; VP16, etoposide; DOX-lip, doxorubicin liposomes; L-Asp, L-asparaginase; BTZ, bortezomib.