Abstract
Haemophagocytic lymphohistiocytosis (HLH) is a rare disorder. This study sheds light on a rare and intriguing case of HLH as the initial symptom in a child with Philadelphia chromosome-positive acute lymphoblastic leukaemia (ph+ALL). This case report, accompanied by a comprehensive literature review, highlights the diagnostic challenges and treatment complexities encountered in the management of such rare manifestations. Moreover, the identification of a novel mutation in the LYST gene adds a unique genetic perspective to the understanding of HLH pathogenesis, potentially opening avenues for further research in this area.