Pediatric myelodysplastic syndrome with cytoplasmic vacuolation in myeloid precursors

Area of Science:

• Hematology
• Pediatric Oncology
• Cell Biology

Background:

• Myelodysplastic syndromes (MDS) are a group of clonal hematopoietic stem cell disorders.
• Pediatric MDS is rare and presents unique diagnostic challenges.
• Cytoplasmic vacuolation is a known feature in erythroid precursors in MDS but is exceptionally uncommon in myeloid precursors.

Observation:

• A 6-year-old boy presented with pancytopenia, a significant reduction in all blood cell types.
• Bone marrow examination revealed dyspoiesis and notably, cytoplasmic vacuolation in myeloid precursor cells.
• Other potential causes including viral, autoimmune, nutritional deficiencies, and genetic syndromes were excluded.

Findings:

• The patient was diagnosed with MDS, refractory cytopenia of childhood subtype, characterized by the rare myeloid precursor cytoplasmic vacuolation.
• An initial allogeneic stem cell transplant achieved hematologic and morphologic remission.
• Late graft failure necessitated a second transplant, which was complicated by sepsis and multiorgan failure, leading to the patient's death.

Implications:

• This case underscores the importance of recognizing rare morphologic findings in pediatric MDS diagnosis.
• The described cytoplasmic vacuolation in myeloid precursors may represent a novel or under-recognized feature of pediatric MDS.
• Understanding such unique presentations can aid in earlier diagnosis and potentially guide therapeutic strategies in pediatric hematologic malignancies.