Figure 7.

Abnormal T-cell populations, continued. All abnormal populations are colored purple, background CD4 positive T-cells are red, and background CD8 positive T-cells are green. A. An example of T-prolymphocytic leukemia/lymphoma (T-PLL), showing abnormal absence of surface CD3 with bright CD7, dim CD2, bright CD5 and CD4 expression. T-PLL can be double negative or double positive for both CD4 and CD8; it rarely expresses CD8 alone. There is no expression of CD279/PD-1 or CD10, in contrast to angioimmunoblastic T-cell lymphoma (AITL) Additional testing showed positive expression of CD52 and TCL1 (not pictured). B. An example of a clonal T-large granular lymphocyte (T-LGL) population, which shows CD8 expression, dim CD5 and CD7 expression, and partial CD56 expression. TRBC1 shows monotypic positive expression consistent with clonality. C. An example of an anaplastic large cell lymphoma (ALCL), ALK negative. This case shows retained expression of CD3, CD2, and variable CD5 expression, with loss of CD7. It expresses CD4 but can be CD8 positive as well. CD25 can also be expressed, often brighter than background T-cells, which can also raise a possibility of adult T-cell leukemia/lymphoma. FSC and SSC parameters show marked increases suggestive of large size and high complexity. Addition of a CD30 antibody is strongly recommended in cases like this one.