Histology of the spleen in B-PLL. (A) Low power view (original magnification ×20) showing replacement of the white pulp and infiltration of the red pulp. (B) High power view (original magnification ×100) of the white pulp showing the typical prolymphocyte morphology with abundant cytoplasm, round nuclei, and a central eosinophilic nucleolus. Courtesy of Andrew Wotherspoon (Royal Marsden Hospital)