Development of secondary T-cell acute lymphoblastic leukemia in a child with hemophagocytic lymphohistiocytosis

Acute myeloid leukemia following etoposide therapy for EBV-associated hemophagocytic lymphohistiocytosis: a case report and a brief review of the literature

Background

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disorder characterized by prolonged fever, cytopenia, hepatosplenomegaly, rash, icterus, and other neurological symptoms. Successful treatment of HLH by etoposide has improved outcomes for children with HLH. However, the development of treatment-related acute myeloid leukemia (t-AML) after the usage of this drug is a concern.

Case presentation

We report a case of acquired EBV-triggered HLH with progression to t-AML following etoposide therapy with cytogenetic abnormality for t (11; 19) (q23; p13) resulting in MLL gene fusion. The development of t-AML was detected 23 months after HLH diagnosis.

Conclusions

Although the successful treatment of HLH by etoposide has improved outcomes for children with HLH, t-AML is a serious complication of topoisomerase II inhibitor therapy and is characterized by the presence of gene rearrangement. This study suggests that HLH patients undergoing therapy with HLH-2004 protocol need monitoring for future malignancy, especially in the initial 2 to 3 years.

Hemophagocytic lymphohistiocytosis masking the diagnosis of lymphoma in an adolescent male

Hemophagocytic lymphohistiocytosis (HLH) association with an underlying lymphoma is an uncommon entity in paediatrics. It may precede lymphoma diagnosis by several years or may occur at the time of remission or relapse of lymphoma. Simultaneous occurrence of HLH & lymphoma is rare. We here with report a case where HLH was the initial presentation which masked the diagnosis of lymphoma, however tissue biopsy revealed the underlying non-Hodgkin's lymphoma.

Advances in understanding the pathogenesis of HLH

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory disorder resulting from immune dysfunction reflecting either primary immune deficiency or acquired failure of normal immune homeostasis. Familial HLH includes autosomal recessive and X-linked disorders characterized by uncontrolled activation of T cells and macrophages and overproduction of inflammatory cytokines, secondary to defects in genes encoding proteins involved in granule-dependent cytolytic pathways. In older children and adults, HLH is associated more often with infections, malignancies, autoimmune diseases, and acquired immune deficiencies. HLH, macrophage activation syndrome, sepsis, and systemic inflammatory response syndrome are different clinical entities that probably represent a common immunopathological state, termed cytokine storm. These conditions may be clinically indistinguishable; all include massive inflammatory response, elevated serum cytokine levels, multi-organ involvement, haemophagocytic macrophages, and often death. Tissues of haematopoietic and lymphoid function are directly involved; other organs are secondarily damaged by circulating cytokines and chemokines. Haemophagocytic disorders are now increasingly diagnosed in the context of severe inflammatory reactions to viruses, malignancies and systemic connective tissue diseases. Many of these cases may reflect underlying genetic predispositions to HLH. The detection of gene defects has contributed considerably to our understanding of HLH, but the mechanisms leading to acquired HLH have yet to be fully determined.

Primary hemophagocytic lymphohistiocytosis in Iran: report from a single referral center

Hemophagocytic lymphohistiocytosis (HLH) is a rare condition characterized by fever, hepatosplenomegaly, and cytopenia, and widespread accumulation of lymphocytes and histiocytes, sometimes with hemophagocytosis, primarily involving the spleen, lymph nodes, bone marrow, and liver. HLH can either occur sporadically (secondary HLH) or as part of a familial syndrome (primary HLH), including familial HLH and the distinct immunodeficiency syndromes. Herein the authors report 6 Iranian patients with primary HLH and their outcome from a single tertiary-care center.