Case 1

The cells are lymphocytes. Once this is determined, it is important to distinguish between a reactive process vs. neoplastic process. In this case, the cells are small and uniform in shape and size and they lack heterogeneous abundant basophilic cytoplasm (seen in reactive lymphoctyes). The lymphocytes also have a mature clumped chromatin with a ‘soccer ball’ pattern of dark and light purple densities. The homogeneous morphology is highly suggestive of a mature lymphoproliferative disorder.

Immunophenotyping using flow cytometry by targeting specific cell markers using fluorescent bound antibodies. This technique helps distinguish between normal and abnormal cells by the proteins they express.

Flow cytometry analysis shows CD19+ B-cells are 84% of total leukocytes with the entire population expressing lambda light chains. More markers were assessed demonstrating CD5+ and CD23+ expression.  Hematopathologists use combinations of markers and morphology to diagnose and subclassify lymphoproliferative disorders. In this case, the phenotype is indicative of Chronic Lymphocytic Leukemia (CLL)

Chronic lymphocytic leukemia is a mature B-cell neoplasm. This usually involves the peripheral blood, bone marrow and secondary lymphoid tissues such as the spleen and lymph nodes. Anemia and other cytopenias can be present due to immune hemolysis or due to leukemic infiltrates in the bone marrow.

Cytogenetic investigation such as fluorescence in situ hybridization (FISH) and array comparative genomic hybridization (aCGH) can identify chromosomal abnormalities such as changes in chromosomal numbers, loss of segmental regions or whole chromosomes, chromosomal rearrangements, gene duplications, and amplifications. Such chromosomal abnormalities are often associated with specific disease subtypes and can inform prognosis and response to therapy. The most common chromosomal aberrations detected in CLL are del13q and trisomy 12.

Conventional cytogenetics doesn’t always detect the chromosomal aberrations in CLL patient’s B cells due to the nature of the CLL lymphocytes; therefore molecular cytogenetics (ex. FISH, CGH and array CGH) is more sensitive in detecting those chromosomal aberrations that may not be otherwise detected by conventional cytogenetics.

Direct Antiglobulin Test (DAT) is performed to determine whether the patient’s erythrocytes were sensitized with IgG immunoglobulin, complement or both. DAT is a useful test to confirm Autoimmune hemolytic anemia (AIHA). AIHA is a result of an altered immune response where the patient produces antibodies against their own erythrocytes. Spherocytes, increased polychromasia and circulating nRBCs may be clues indicating autoimmune hemolytic anemia. The development of AIHA in the context of CLL would be an indication to treat the lymphoproliferative disorder.

LDH is released into the bloodstream during acute or chronic cell damage. LDH is usually elevated in advanced, transformed cases of CLL. The transformation of CLL to diffuse large B cell lymphoma is called Richter's transformation.