Figure 1: CLL with Trisomy 12-Blood
There is marked lymphocytosis with increased numbers of circulating CLL lymphocytes with clumped nuclear chromatin and scattered smudge cells/basket cells.
Figure 2:CLL with Trisomy 12-H&E
Bone marrow core biopsy demonstrates 90% cellular marrow extensively involved by diffuse lymphoid infiltrate of CLL cells. Image at the top right shows vague nodular structure consistent with growth center. At higher power, the lump chromatin and small cytomorphology of CLL cells is apparent. At the image in the bottom left, a normal megakaryocyte can be seen towards the right side.
Figure 3: PAX5 immunostain in CLL
The infiltrate of CLL cells is diffusely positive for PAX5, nuclear B-cell marker. CD20 was already performed and found to be positive by flow cytometry as shown below.
Figure 4: CD3 and CD5 and CLL
Comparison of the CD3 and CD5 immunostain shows markedly increased numbers of CD5 positive cells compared to CD3. The CD3 stain on the left side shows only scattered positive cells, consistent with T cells while the bulk of the infiltrate is negative for CD3. CD5 however shows moderate to bright staining in the T cells (black arrows) while the CLL cells demonstrate dim staining uniformly.
Figure 5: CLL with Trisomy 12-LEF1 & Zap70
Lef1 highlights scattered T-cells (solid black arrows) that stain brightly. CLL cells are focally positive with dim expression. LEF1 is a nuclear stain that may work suboptimally in decalcified B-5 fixative.
CLL cells are moderately positive for ZAP70. There are scattered T-cells (internal control) that show bright ZAP70 expression.
Figure 6: CLL with Trisomy 12-Aspirates
The lower power image (on the left) shows sheets of small lymphocytic cells consistent with CLL, a single megakaryocyte to the bottom right of the image, and a rare prolymphocyte.
The higher power image (on the right) shows the same and highlights some myelocytes (indicated by the arrows).
Figure 7: CLL with Trisomy 12-Flow Cytometry 1
The CD19 with side scatter (pictured on the left) shows that B cells are 78% of all cells.
The CLL cells (colored in blue) express dim CD5 and CD23 (pictured on the right).
Figure 8: CLL with Trisomy 12-Flow Cytometry 2
CLL cells (colored in blue) express moderate CD20 (pictured on the left). Note the expression levels of CD20 are brighter than typical CLL, keeping with the trisomy 12 disease. Trisomy 12 disease is associated with an atypical immunophenotype including bright CD20 and increased circulating prolymphocytes. In this case, prolymphocytes were about 5% of all cells in both the blood and bone marrow aspirates. Expression of CD38 is associated with poor outcome in CLL.
All cells depicted (pictured on the right) come from the lymphocyte gate as noted above. CLL cells (colored in blue) are positive for CD38 and dim to negative for CD5. Note the T cells (colored in purple) are moderate for CD5.
Figure 9: CLL with Trisomy 12-Flow Cytometry 3
CLL cells (colored in blue) show a dim restricted kappa light chain. Dim surface light chain expression is also typical of CLL as compared to other mature B cell leukemias and lymphomas. Trisomy 12 CLL may express moderate-bright light chain in some instances.
Figure 10: CLL with Trisomy 12-Flow Cytometry 4
Note that this is an ungated analysis including all cells. The two smaller pink populations depict T cells expressing either CD4 or CD8. The larger cluster on the bottom left depicts CLL cells that are negative for both CD4 and CD8.
The population on the top right shows T cells positive for CD3 and CD2. The cluster on the bottom left depicts CLL cells which are negative for CD3 and CD2.
