B-cell ProLymphocytic Leukemia (B-PLL)

>55% of the circulating lymphocytes are prolymphocytes, medium to large-sized cells (twice the size of small lymphocyte), moderately condensed chromatin, a single prominent central nucleolus and a moderate amount of (pale) basophilic cytoplasm.
The cells typically show strong expression of surface Ig, strong CD20 and normal other pan-B cell markers by flowcytometry. CD5 and CD23 are only expressed in 1/3 of the cases, CD38 in about 1/2 of the cases. CD10, CD25, CD11c are not expressed.