How I Diagnose Low-grade Myelodysplastic Syndromes

Alexa J. Siddon, MD; Robert P. Hasserjian, MD


Am J Clin Pathol. 2020;154(1):5-14. 

In This Article


The diagnosis of low-grade MDS is one of the most challenging areas of hematopathology, as there is high interobserver variability in the morphologic assessment of dysplasia and a myriad of non-MDS causes of cytopenia and dysplasia in elderly populations most commonly affected. In addition, the integrative aspect of the MDS evaluation, which incorporates peripheral blood findings, bone marrow assessment, flow cytometry, cytogenetics, and molecular genetic studies, can be difficult to consolidate. In the era of increasing knowledge of the molecular genetic underpinnings of these clonal diseases, our assessment of MDS is becoming increasingly complex. When this complex array of information gives "mixed messages," the pathologist should step back and look at the entire case carefully, always considering potential nonneoplastic MDS mimics. There is no shame in rendering a descriptive diagnosis and recommending close clinical follow-up and a repeat bone marrow sample if a definitive conclusion cannot be made on the available data.