Co-Existence of Two Abnormal Clones: Diploidy with a Unique Inverted 5q Deletion Not Involving EGR1 and Near-Tetraploidy with Monosomy 7 in Biphenotypic Leukemia Arising from Myelodysplastic Syndrome

Biphenotypic Acute Leukemias (BAL) account for less than 5% of all cases of acute leukemias. Cytogenetic abnormalities are very common in BAL occurring in 59-91% of cases. These leukemias are generally associated with a poor prognosis with no clear consensus existing on their optimal management. We report a case of a biphenotypic acute leukemia arising in a patient with a prior history of Myelodyplastic Syndrome (MDS) expressing two cytogenetically distinct clones: a diploid clone with a unique 5q inversion/ deletion not involving EGR1 and a second clone of cells with a near -tetraploidy having monosomy 7 as the main numerical abnormality. The patient is currently alive and remains in remission seventeen months following diagnosis of his BAL after undergoing induction chemotherapy with idarubicin, cytarabine and cladribine and a consolidative double cord blood transplant.