Caracté ristiques biologiques des LAM à cup-like nuclei, une entité rare associée à une mutation de NPM1 et de FLT3: Confusion diagnostique possible avec une leucémie aiguë promyélocytaire variant microgranulaire ; à propos de trois cas

We report here three cases of cup-like leukemia, a rare and underdiagnosed form of acute myeloblastic leukemia. Clinical and biological findings are relatively stereotypical : high blood cell counts, high frequency ofNPM1 and FLT3mutations and normal karyotype, and may resemble microgranular variant of acute promyelocytic leukemia because of frequent disseminated intravascular coagulation, mature phenotypic feature with low or absent expression of CD34 and HLADR and peculiar blastic morphology (proeminent nuclear invaginations). Therefore, recongnizing cup-like nuclear leukemia is important to avoid misdiagnosis of promyelocytic leukemia and should guide specific molecular analyses.