Pleural effusion of an 83-year-old female patient with a history of NHL. a, b Monomorphic middle-sized lymphocytes and a few blasts in the sediment smear (Papanicolaou, original magnification ×400) (a) with immunocytochemical expression of the bcl2 antigen (b). c FC demonstrating a large CD19-positive B-cell population with κ chain restriction and coexpression of CD10, corresponding to the diagnosis of FL.