The case study interpretation session held at the International Clinical Cytometry Society (ICCS) annual meeting in Portland in 2011 included four cases that illustrate various aspects of flow cytometric immunophenotyping of B-cells. These cases touch on the phenotypic findings characteristic of different subtypes of B-lineage lymphoid neoplasms, optimal analysis strategies for identifying neoplastic B-cells, the significance of identifying very small populations of abnormal B-cells, and lineage assignment in cases with ambiguous antigen expression.

I would suggest that you use these cases to test your knowledge. First review the clinical information, then download and analyze the listmode files provided in the supplemental information, compare your analysis with the example analysis provided by the authors, and finally read the case discussion and diagnosis. I hope these cases provide information that is useful in your practice of clinical flow cytometry. Additional cases addressing various aspects of flow cytometric immunophenotyping of T-cells are available in the CSI-Houston, 2010 report (Cytometry Part B, Clinical Cytometry 80B:254; 2011).

Fiona E. Craig*, * Division of Hematopathology Department of Pathology University of Pittsburgh School of Medicine and Clinical Flow Cytometry Laboratory UPMC-Health System, UPMC-Presbyterian Pittsburgh, Pennsylvania 15213-2582. E-mail: