Objectives: Myelodysplastic syndromes Myelodysplastic syndromes: (my-eh-lo-diss-PLASS-tik SIN-dromez) A group of disorders where the bone marrow does not work well, and the bone marrow cells fail to make enough healthy blood cells. Myelo refers to the bone marrow. Dysplastic means abnormal growth or development. People with MDS have low blood cell count for at… (MDS) are a group of myeloid neoplasms that are often difficult to diagnose due to their pathologic and clinical heterogeneity. The key features of MDS are peripheral blood cytopenias, ineffective hematopoiesis hematopoiesis: (hi-mat-uh-poy-EE-suss) The process of making blood cells in the bone marrow. manifesting as morphologic dysplasia, and clonal genetic abnormalities. The most difficult diagnostic dilemmas often arise in low-grade MDS cases (lacking excess blasts blasts: See Blast Cells. ), which can be difficult to distinguish from other causes of cytopenia cytopenia: (sie-tuh-PEE-nee-uh) A shortage of one or more blood cell types. Also called a low blood count. . This distinction requires the integration of information from the peripheral blood (both CBC parameters and morphology morphology: The study of the structure and form of an organism or one of its parts. ), bone marrow bone marrow: The soft, spongy tissue inside most bones. Blood cells are formed in the bone marrow. morphology, genetic studies, and interrogation of the clinical record to exclude secondary causes.
Methods: We discuss the approach to the diagnosis of low-grade MDS (cases lacking increased blasts), including a diagnostic algorithm and two illustrative cases.
Results: The appropriate use of ancillary studies is important to support or dispute the likelihood of low-grade MDS in conjunction with the findings of morphologic dysplasia. Interpreting the results of cytogenetics cytogenetics: (sie-toe-juh-NEH-tiks) The study of chromosomes (DNA), the part of the cell that contains genetic information. Some cytogenetic abnormalities are linked to different forms of myelodysplastic syndromes (MDS). and next-generation sequencing can be challenging and must incorporate the emerging knowledge of clonal hematopoiesis of indeterminate potential.
Conclusions: The role of pathologists in integrating data from multiple sources in the diagnosis of low-grade MDS is evolving and becoming increasingly complex; in this challenging diagnostic setting, it is important to feel comfortable with uncertainty and maintain a conservative approach.