Leukapheresis in Pediatric T-ALL with Extreme Hyperleukocytosis: A Case Highlighting the Importance of Early Recognition.

Hyperleukocytosis (HL) in acute leukemia is associated with increased morbidity and mortality, mainly secondary to the effects of leukostasis. Many strategies for cytoreduction exist, however prompt initiation of chemotherapy is paramount. Leukapheresis is an additional strategy, though there is conflicting data for its use in HL in acute leukemia. Below we detail a case of HL and leukostasis in newly diagnosed pediatric T-cell acute lymphoblastic leukemia and the use of leukapheresis. We highlight that leukapheresis can rapidly and safely reduce the white blood cell count, as an adjunct to symptom management, and potentially prevent life-threatening complications while not delaying chemotherapy initiation. However, this case underscores that early recognition of HL prior to the development of severe neurological complications is critical, as once cerebral leukostasis with intracranial hemorrhage is established, neither leukapheresis nor chemotherapy may alter the fatal outcome. The patient's initial presentation with epistaxis and hematemesis two days prior-without laboratory evaluation-represents a missed opportunity that may have allowed earlier recognition and intervention.