Abstract:To the Ediror: Our case is different from that of Muroi et al. in that there are two distinct populations of proliferating cells.the myeloblasts and the mast cells [I].In their case it remains specula...To the Ediror: Our case is different from that of Muroi et al. in that there are two distinct populations of proliferating cells.the myeloblasts and the mast cells [I].In their case it remains speculative to consider the "mast cells" to be derived from the same clone as the leukemic population.However, it should be noted that the abnormal eosinophils in M4Eo may appear hypolobulated, may contain basophilic granules, and are CAE positive 121, thus mimicking mast cells.We have reviewed our cases of M4Eo (three cases) but have failed to detect increased mast cells either in the peripheral blood or in the bone marrow, and we doubt the validity of the conclusion reached by Muroi et al. that "circulating mast cells may be detected by a careful observation in the case of M4Eo with hyperleukocytosis."Read More