Recurrent isochromosome 21 and multiple abnormalities in a patient suspected of having acute myeloid leukemia with eosinophilic differentiation—a rare case from South India
A 76-year-old man of Indian origin, with history of ischemic heart disease, was presented to the Outpatient Clinic of Medical Oncology, Regional Cancer Centre due to marked variation in blood count, in addition to anemia, thrombocytopenia, mild splenomegaly, and leukocytosis. Initial complete blood count displayed 4.8 g/dL of hemoglobin, leukocyte count of 50 500 cells/mm3 undiluted blood, and thrombocyte count of 65 000 cells/mm3 undiluted blood. Blood picture showed predominant neutrophils, marked shift to the left with atypical monocytes, 12% blasts, and 6% basophils. Initial bone marrow study revealed hypercellular marrow with 35% blasts and mild eosinophilia. Blasts were peroxidase-positive. The hematological and clinical parameters were consistent with AML-M4 [E0] that resembles blast crisis of chronic myeloid leukemia (CML). Using conventional cytogenetics and fluorescence in situ hybridization (FISH), the case was confirmed not to be CML blast crisis. Using standard protocols, unstimulated bone marrow culture and chromosome analysis were performed on G-banded metaphases using Cytovision software. The karyotypes were prepared according to the International System for Human Cytogenetic Nomenclature (2005). FISH was performed using BCR/ABL Dual Color, Dual Fusion Translocation Probe (Vysis). All studies were carried out after obtaining written informed consent from the patient and approval from the Institutional Review Board of the Regional Cancer Centre. Cytogenetic analysis using G-banding revealed the karyotypes in 50 intact metaphases, and the results are summarized in . In addition, rare phenomena including tetraploid endoreduplication and ring chromosomes were noted.