Cup-like blasts in acute myeloid leukemia

A patient with AML with normal karyotype and the cytological pattern of cup-like blasts (CLB) is reported. The typical morphology on Pappenheim stained blood smears is shown. In addition transmission electron microscopy pictures demonstrate impressively the invaginated nuclear pocket compressing the chromatin. Cup-like blasts usually do not express CD34. There is a close relationship of CLB-AML with the molecular aberrations of NPM1 and/or FLT3-ITD.Am. J. Hematol. 90:847–848, 2015. © 2015 Wiley Periodicals, Inc.