#00063650

A 68-year-old female presented for anemia requiring transfusion and marked lymphocytosis (253 x 109/L; 90% of white blood cells). She has been diagnosed with T cell prolymphocytic leukemia (T-PLL) at outside hospital. (a) Peripheral blood smear (Wright and Giemsa stain, Cellavision DM image) showing atypical lymphocytes with irregular nuclei. Some cells demonstrate features of cytoplasmic blebbing (black arrow), prominent nucleolus (green arrow), and abundant cytoplasm (red arrow). (b-f) Flow cytometry analysis of the T lymphocytes. (b) Dot plot of side scatter versus CD45 showing heterogeneous CD45 expression on T cells (green: CD45 negative; blue: CD45 dim-moderate positive; purple: CD45 strong positive). (c) Dot plot of CD5 versus surface CD3 shows that these T cells are positive for CD5, negative for surface CD3. (d) Dot plot of TdT versus cytoplasmic CD3 shows that these T cells are positive for cytoplasmic CD3, negative for TdT. (e)Dot plot of CD2 versus CD7 shows that both markers are expressed. (f) Dot plot of CD8 versus CD4 showing positive expression of CD4 only. (g) Dot plot of CD56 versus CD25 showing lack of expression of both markers. These findings are consistent with the diagnosis of T-PLL. The atypical T cells show a heterogenous CD45 expression. They are positive for CD2, cytoplasmic CD3, CD4, CD5, CD7, CD9, and CD33 (minimal); negative for CD1a, surface CD3, CD8, CD13,  CD25, CD34, CD117, cMPO, CD38, CD56, CD10, TdT, cIgM, cCD22, CD23, cCD79a, CD19, CD20, Kappa, and Lambda.