Paraplegia as the presenting manifestation of extramedullary megakaryoblastic transformation of previously undiagnosed chronic myelogenous leukemia

Abstract

Extramedullary tumors, also known as granulocytic sarcomas (GS), occur most frequently in acute myelogenous leukemia (AML). They may signal the onset of the accelerated phase of chronic myelogenous leukemia (CML) or the blastic transformation of a myeloproliferative disorder. Occasionally, a GS may be the presenting sign of undiagnosed AML, and rarely the presenting sign of undiagnosed CML or aleukemic leukemia. Paraplegia due to a spinal cord GS is an extremely rare presentation of undiagnosed leukemia. This is the first case report of paraplegia as the presenting manifestation of extramedullary megakaryoblastic transformation of previously undiagnosed CML. A 53-year-old woman reported back pain for 6 days, rapidly progressing to paraplegia. Physical examination noted a large abdominal mass and flaccid paralysis in both lower extremities. Spinal MRI revealed a T4-T6 vertebral mass causing spinal stenosis and cord compression. Tumor debulking and laminectomy were performed emergently. The tumor consisted of noncohesive blast cells. The CBC revealed a leukocyte count of 238,300/ml and a differential consistent with CML. Reexamination of the patient found that the abdominal mass was a giant spleen. Further immunohistochemical studies of the tumor were consistent with extramedullary acute megakaryoblastic blast transformation of CML. Although extramedullary blast crises herald the accelerated phases in~10% of CML cases, megakaryoblastic blast transformation of CML accounts for less than 3% of these cases. The combination of acute paraplegia and megakaryoblastic transformation in a previously undiagnosed patient with CML is extremely rare and may pose a diagnostic dilemma. Am. J. Hematol. 82:150-154, 2007. V V C 2006 Wiley-Liss, Inc.

De novo acute megakaryoblastic leukemia with p210 BCR/ABL and t(1;16) translocation but not t(9;22) Ph chromosome

“…Myelofibrosis or increased bone marrow reticulin are a prominent aspect in most AMKL patients. In some cases, megakaryoblastic crisis could be the first presentation of CML, and not distinguishable from de novo AMKL [12-16]. This case represents de novo AMKL in our opinion, because the patient had no basophilia and eosinophilia upon presentation, which are often seen in blast crisis of CML [17].…”

“…Furthermore, our patient had only mild splenomegaly. Moderate or severe splenomegaly is common in blast crisis of CML [13,16]. …”

Sudden blastic crisis and additional chromosomal abnormalities during chronic myeloid leukemia in the imatinib era

“…15 The incidence of EMD is reported to be 4%-17% in patients with CML, and it commonly occurs in the bone, lymph nodes, skin, soft tissues, and central nervous system. 16,17 It may precede the medullary disease progression by months to years, or it may signal the advanced phase in a patient with known CML, 15,16 as was also seen in the present patient. There is no established standard therapy for EMD.…”

ecancermedicalscience

“…Chronic myeloid leukaemia (CML) presenting primarily as megakaryocytic blast crisis is very rare, with very few case reports published to date [2, 3]. This case report describes a 36-year-old woman who presented with anaemia and massive splenomegaly with peripheral blood and bone marrow showing features of AMeL.…”