Chediak-Higashi Syndrome Case Report: Cytomorphology Linking Clinical and Laboratory Findings

We report a fatal pediatric case of Chediak-Higashi syndrome (CHS) in a 4-year-old girl, initially misdiagnosed as Griscelli syndrome.

Laboratory findings showed pancytopenia (hemoglobin: 66 g/L, thrombocytopenia: 97 x 10⁹/L, leucope-nia: 2.6 x 10⁹/L) and pathognomonic dense giant cytoplasmic granules observed throughout myeloid maturation, from precursors to mature neutrophils. Eosinophils in both peripheral blood and bone marrow specimens provide morphological evidence of Chediak-Higashi syndrome, later complicated by EBV-triggered hemophagocytic lym-phohistiocytosis (HLH).

The patient was definitively diagnosed with CHS. During preparation for hematopoietic stem cell transplantation (HSCT), her condition progressed to fatal HLH despite adherence to the HLH-2004 protocol, culminating in septic shock.

This case highlights CHS's diagnostic challenges, the lethality of HLH, and the critical need for early HSCT before accelerated-phase onset.