Hemophagocytosis by Blasts in a Child With Acute Monocytic Leukemia After Chemotherapy

Abstract

Objective: To describe the case of a child who presented hemophagocytic lymphohistiocytosis (HLH) associated with acute monocytic leukemia after chemotherapy, with hemophagocytosis caused by leukemic cells. Case description: In a university hospital in Southern Brazil, a 3-year-old female was diagnosed with acute monocytic leukemia with normal karyotype. The chemotherapy regimen was initiated, and she achieved complete remission six months later, relapsing after four months with a complex karyotype involving chromosomes 8p and 16q. The bone marrow showed vacuolated blasts with a monocytic aspect and evidence of hemophagocytosis. The child presented progressive clinical deterioration and died two months after the relapse. Comments: HLH is a rare and aggressive inflammatory condition characterized by cytopenias, hepatosplenomegaly, fever, and hemophagocytosis in the bone marrow, lymph nodes, spleen, and liver. Although rare, malignancy-associated HLH (M-HLH) is fatal. The patient in this case report met five out of the eight established criteria for HLH. The evolution of the patient’s karyotype, regardless of the diagnostic profile, seemed secondary to the treatment for acute monocytic leukemia. In this case, the cytogenetic instability might have influenced the abnormal behavior of leukemic cells. This is a rare case of HLH in a child with acute monocytic leukemia.

Peripheral Blood Blast Erythrophagocytosis After Chemotherapy in a Patient with Acute Monoblastic Leukemia

“…Blast hemophagocytosis is mostly reported at the time of the onset and is associated to abnormal karyotype [1,[3][4][5][6][7][8][9]11], it rarely happens after chemotherapy, as in our case, and seems to be associated to karyotype evolution in patients presenting with normal karyotype at the onset [1].…”

“…The percentage of blasts involved may vary extremely, from 0.2 to 36.7% [1,[3][4][5][6][7][8][9]11]. The specificity of blast hemophagocytosis is controversial and cases reported in the literature do not mention any specific explorations or dedicated treatment as in M-HLH [3,11,13].…”

“…Blast hemophagocytosis is found in about 1% of acute leukemia, particularly acute myeloid leukemia (AML) and especially those of a monoblastic or monocytic lineage. It may be associated or not to M-HLH [1]. This phenomenon is more rarely observed in lymphoblastic leukemia [2].…”

“…The mechanism behind this blast's behavior remains unclear and associations have been found with some chromosomal abnormalities, especially t (8;16), but also with other translocations as t(10;17), t(16;21), t (3;8;17) and t(3;8) regardless of the morphological type; M0, M1, M4, M5a, M5b or even M7 [1,[3][4][5][6][7][8]. Many mechanisms have been suggested by authors as the expression of binding receptors involved in hemophagocytosis, karyotype evolution related to genetic instability and treatment toxicity [2,3,6,9,10].…”

Eltrombopag and its iron chelating properties in pediatric acute myeloid leukemia

“…Acute myeloid leukemia (AML) represents the 20% of total childhood leukemia diagnoses [ 1 ], even though it remains the most frequent type of acute leukemia in the elderly [ 2 ]. In 0–2 year-old children, this kind of leukemia is characterized by poor prognosis, with a survival rate around the 60% [ 3 ], and high treatment-related toxicity [ 4 ]. In infants the most common subtype of AML is the acute monocytic leukemia (AMoL) responsible for high mortality and morbidity [ 5 ].…”