Unusual CD34+ dysplastic giant platelets complicate myelodysplastic syndrome diagnosis

Background

Myelodysplastic syndromes (MDS) are a group of hematopoietic disorders characterized by ineffective hematopoiesis, with manifestations of cytopenias in one, two, or three lineages. CD34⁺ micromegakaryocytes and giant platelets are very rarely seen in MDS patients but may lead to unnecessary treatments. Therefore, we report and follow up on an MDS case with such an unusual finding.

Case presentation

A 57-year-old male veteran with a history of MDS, alcoholic cirrhosis, and portal hypertension presented to the Emergency Department in 2020 for evaluation after a blackout, at which time peripheral blood samples and bone marrow biopsies were obtained. Flow cytometry analysis of his peripheral blood detected 8% CD34⁺ cells. This finding raised the possibility of acute leukemic transformation from MDS. Further studies revealed that these CD34⁺ cells represented dysplastic micromegakaryocytes and giant platelets rather than blasts. During his 4-year follow-up, the patient was alive and complained only of easy fatigability, lasting several weeks. His laboratory results showed pancytopenia and persistent iron-deficiency anemia.

Conclusions

The finding of CD34⁺ dysplastic giant platelets in our case is unusual. Such findings could lead to misdiagnosis of acute leukemia. It is important for pathologists to integrate morphologic and flow cytometric findings for overall diagnosis. This will help prevent overdiagnosis of acute leukemia in MDS patients. Furthermore, studying the population and behavior of CD34⁺ dysplastic platelets in MDS is valuable and may improve understanding of disease pathology.