Hemophagocytic lymphohistiocytosis after initiation of chemotherapy for bilateral adrenal neuroblastoma

Hemophagocytic lymphohistiocytosis (HLH) is a rare and aggressive syndrome characterized by overactivation of the immune system. Although secondary HLH has been frequently associated with malignancies, this entity is rarely triggered by solid tumors, such as neuroblastomas. Herein, we describe a 14-monthold girl with a late diagnosis of bilateral adrenal neuroblastoma who developed HLH 6 days after the initiation of chemotherapy. On the basis of the large tumoral mass and the time of onset of her symptoms suggestive of HLH, we hypothesize that tumor cell destruction induced by chemotherapy drugs was the trigger to the development of hematophagocytic lymphohistiocytosis syndrome.