PMC4421110_01
(A) Bone marrow clot section shows sheets of large blasts with irregular nuclei and abundant eosinophilic cytoplasm (Hematoxylin & Eosin, 100x). (B) Bone marrow aspirate smear contains numerous monoblasts with oval and folded nuclei (Wright-Giemsa, 100x). (C) Conventional cytogenetics of bone marrow showed a 47,XXY karyotype in all 20 metaphases analyzed. (D) Interphase FISH study of monolayer cultured bone marrow stromal cells using probes for DXZ1 (chromosome X alpha satellite DNA) and DYZ1 (chromosome Y satellite DNA) (Abbott Molecular) showed an XXY hybridization pattern in all 50 nuclei analyzed.
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The biopsy was hypercellular (95% cellularity) and was replaced by sheets of blasts (Fig. 1A). On the aspirate smear, there were 76% monoblasts (Fig. 1B), confirmed by flow cytometric immunophenotyping. Bone marrow karyotype was abnormal, with all metaphases (20 of 20) containing an additional X chromosome as the sole aberration (Fig. 1C). AML, a monolayer culture of non-neoplastic bone marrow stromal cells was studied to obtain a constitutional karyotype. Although no metaphases were obtained from the monolayer culture, interphase FISH analysis revealed that all scored nuclei contained two copies of the X and one copy of the Y chromosome, confirming that this patient s constitutional karyotype was 47,XXY (Fig. 1D).