Successful treatment of recurrent malignancy-associated hemophagocytic lymphohistiocytosis with a modified HLH-94 immunochemotherapy and allogeneic stem cell transplantation.

Acquired hemophagocytic lymphohistiocytosis (HLH) triggered by a known or still to be recognized malignancy is a life-threatening hyperinflammatory syndrome due to massive cytokine release from activated lymphocytes and macrophages. Malignancy-associated HLH (M-HLH) often impedes adequate treatment of malignancy and has the worst outcome compared with any other form of HLH. The incidence of M-HLH is unknown, and there are no published treatment recommendations addressed to this HLH form. Here, we report the case of a young woman with recurrent ALK1-positive anaplastic large T-cell lymphoma and M-HLH successfully treated with a modified HLH-94 protocol, allogeneic stem cell transplantation (alloSCT) and donor lymphocyte infusion (DLI). More than 3 years after DLI, the patient is alive, in complete remission from her malignancy and HLH-free, although suffering from extensive chronic graft-versus-host disease. AlloSCT and, if needed, DLI performed to consolidate remission of malignancy and HLH may have a curative impact on both entities. We propose that when discussing possible treatment options for patients with M-HLH, alloSCT should be considered in eligible individuals.