Hemophagocytosis associated with leukemia: a striking association with juvenile myelomonocytic leukemia.

The aim of this study was to describe the characteristics and outcome in a group of pediatric patients with hematological malignancies who developed hemophagocytosis at diagnosis or during the disease course. Eight patients with hematological malignancy and associated hemophagocytosis were included. The initial diagnosis was juvenile myelomonocytic leukemia (JMML) in five, nonlymphoblastic leukemia (ANLL) in two, and T-cell lymphoma associated with myeloproliferative syndrome in one patient. Hemophagocytosis was concomitantly present at the time of diagnosis of the primary disease in four of the five patients with JMML and in the two patients with ANLL. Three had abnormalities related to chromosome 8 [(trisomy 8, monosomy 8, and t (8;13) (p11; p12)], and one had inversion 16. Multiple chromosomal losses were present in one patient, including both chromosomes 8 and 16. Bone marrow karyotyping revealed 46, XX; 47, XXX mosaicism in one patient. Two patients had PTPN11 mutation and one patient k-RAS mutation. The patients with JMML and neurofibromatosis (n = 2), the patient with lymphoma and t (8;13) positive AML, and a fourth patient with PTPN11 mutation did not remit and had unfavorable outcomes.