Flow cytometry (FCM) analysis may be an important tool and provide diagnostic clarity in cases where patients with cytopenia are suspected of having myelodysplastic syndrome (MDS), according to a new case series published in the journal Cytometry Part B Clinical cytometry.

Corresponding author Theresia M. Westers, PhD, of University Medical Centers Amsterdam in the Netherlands, and her colleagues wrote that current guidelines already call for flow cytometry analysis in cytopenic patients suspected of having a SMD, but they said most studies on the issue fail to elucidate how these tests may impact individual cases.

“Many reports of FCM in MDS focus on examples of outlying immunophenotypic features without placing single patient findings in the context of clinical features and other diagnostic tools,” Westers and colleagues said.

Instead, the investigators wanted to show how FCM can be useful in determining precise diagnoses for individual patients.

The 6 cases included in the report represented a variety of diagnostic issues and patient presentations. Two of the cases included patients whose diagnoses were confirmed based on FCM results that showed low cellularity and poor quality bone marrow (BM) aspirates.

One of these cases was a 5-year-old boy, an unusual case in a disease category where most of the literature relates to older patients. The boy presented with fatigue, bruising and a history of upper respiratory infections.

Her doctors initially suspected hypocellular MDS or anemia as the cause of her distress. After doing the FCM, the doctors refined their diagnosis to refractory childhood cytopenia with aplastic anemia as the differential diagnosis.

“A [bone marrow] trephine examination showed hypocellular, nearly aplastic marrow with reduced erythro- and myelopoiesis,” the authors reported. “Definite features of myelodysplasia were not observed and the pathologist suspected aplastic anemia. Cytogenetics showed a normal karyotype (46, XY), molecular analyzes were not performed.

Doctors decided to take a second bone marrow sample about 4 weeks later. This time, histological, cytomorphological and immunological analyzes all suggested bone marrow aplasia and not dysplasia.

“The child was referred for allogeneic stem cell transplantation (allo-HSCT) and is doing well,” the investigators concluded.

In a separate case, a 33-year-old woman 30 weeks pregnant was examined for rapid onset anemia and nucleated red blood cells on her peripheral blood (PB) smear. A morphological assessment led investigators to suspect MDS, but they said her young age and rapid onset caused them to question the diagnosis.

“Being pregnant, young, with no excess blasts, no defining cytogenetic abnormality, and rapid onset of cytopenia, additional diagnostic information from FCM analysis was instrumental in making this diagnosis,” the authors wrote. “The patient was closely monitored for the remaining period of her pregnancy, but later progressed to acute myeloid leukemia.”

The investigators concluded that FCM can be an essential tool in the early phase of diagnostic investigation, but they added that the results of such an analysis must be considered in the context of a larger picture of the patient’s case. .

“In general, the interpretation of FCM results should be done in the context of an integrated multimodal diagnostic approach, i.e. discrepancies with results from other diagnostic tools should be considered with care,” they wrote.

Reference:

Westers TM, Saft L, van der Velden VHJ, et al. A series of case studies illustrating the role of flow cytometry in the diagnostic workup of myelodysplastic syndromes. Cytometry B Clin Cytom. Published online February 18, 2022. doi:10.1002/cyto.b.22061