Novel t(5;19) Translocation in a Patient with PDGFRB Associated Chronic Leukemia: Implications for Treatment Strategy

Myeloproliferative disorders are variable disorders, based on the genetic abnormality present and the cell line progenitors that are affected. In this case, we discuss a novel gene translocation in the subset of PDGFRB mutations, first seen with prominent hyperbasophilia. This case demonstrates the possibility for lower therapeutic doses of imatinib mesylate than previously reported, in order to control leukocyte counts and reverse the genetic mutation. 1. Case Presentation 1.1. History J. H. is a 54-year-old male who initially presented to the emergency department with complaints of shortness of breath and peripheral edema, which had been occurring progressively over the preceding several days. His review of symptoms was also positive for an unintentional 30-pound weight loss and nightly sweats for at least three months. He had not seen a physician for many years, and his past medical history was positive only for chronic obstructive pulmonary disorder and a possible transient ischemic attack several years before this presentation. His family history was positive only for diabetes and hypertension. He admitted to a fairly heavy history of alcohol consumption and tobacco abuse. 1.2. Hospital Course His initial workup targeted his heart failure symptoms, with a chest X-ray in the emergency department revealing pulmonary edema and an echocardiogram confirming a left ventricular ejection fraction of 35%. A computed-tomography scan of the abdomen revealed evidence of cirrhosis, with esophageal varices and splenomegaly. Leukocytosis was noted, with a leukocyte count of 52.57？K/mcL. He was also found to be anemic, with a hemoglobin of 7.6？g/dL, and thrombocytopenic, with a platelet count of 61,000. The patient responded well to diuresis and was stabilized from a cardiovascular and respiratory standpoint. Working diagnosis included both ischemic cardiomyopathy and alcoholic cirrhosis. His leukocytosis was initially thought to be reactive; however, his complaints of weight loss and night sweats prompted further investigation. Manual differential of his complete blood count revealed a left shift, with neutrophils 65%, lymphocytes 2%, monocytes 10%, eosinophils 7%, basophils 1%, metamyelocytes 12%, and myelocytes 3%. Iron studies, folate, and B12 levels were normal. Consultation to Hematology/Oncology was made. FISH for bcr-abl, along with t(9;22) and JAK-2, was sent to rule out CML and PRV. Peripheral blood for cytogenetics was also sent, with planned outpatient follow-up in the Hematology/Oncology clinic. 1.3. Follow-Up The patient was seen in follow-up two