Juvenile myelomonocytic leukemia in CBL syndrome associated with germline splice-site mutations: Two case reports and...

Area of Science:

• Pediatric Hematology
• Oncology
• Immunology

Background:

• Juvenile myelomonocytic leukemia (JMML) is a rare, aggressive clonal hematopoietic stem cell disorder in young children.
• Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome of excessive immune activation.
• Distinguishing primary HLH from secondary HLH is critical for appropriate management.

Observation:

• CBL syndrome, a subset of JMML, presents diagnostic challenges.
• Clinical and laboratory findings in CBL syndrome can mimic HLH.
• Accurate differentiation between primary HLH and HLH secondary to CBL syndrome is essential.

Findings:

• The study emphasizes applying HLH diagnostic criteria during JMML evaluation.
• This approach helps identify primary HLH, which requires distinct therapeutic strategies.
• It differentiates primary HLH from HLH secondary to CBL syndrome, guiding treatment decisions.

Implications:

• Accurate diagnosis of primary HLH in JMML, particularly CBL syndrome, improves patient outcomes.
• Timely initiation of appropriate HLH-specific therapy can be life-saving.
• This diagnostic strategy refines the understanding and management of complex pediatric hematologic disorders.