EXTREME PERIPHERAL ERYTHROBLASTOSIS AND HEMOGLOBIN LEVEL
INCREASE AS A DEBUT OF LEUKEMIC TRANSFORMATION OF ESSENTIAL
POSTER 28
THROMBOCYTHEMIA
Gergana Tsvetkova and Evgueniy Hadjiev, Medical University - Sofia, Faculty of Medicine, Department
of Internal diseases, UMHAT “Alexandrovska”
Clinic of hematology, Sofia, Bulgaria
Essential thrombocythemia (ET) is a chronic myeloproliferative disorder with long-term
evolution and nearly normal life expectancy. The thrombotic and haemorrhagic complications
appear to have the major impact on the survival, while the incidence of blast transformation
during the first decade after the diagnosis rarely exceeds 1%.
Objectives: We present a case of atypical progression and blast transformation in a patient
with ET.
Methods: An 89 years old female patient was diagnosed at our department with a
myeloproliferative disorder – ET, when she was at the age of 80. The diagnosis was stated
according to the WHO-criteria, respectively confirmed by histologic and immunohistochemical
assay of a bone marrow biopsy specimen and a molecular genetic testing. During the past 9
years she was treated with Hydroxyurea with optimal control and regularly monitored. The
leukemic progression of the analyzed case was verified by a subsequent bone marrow biopsy,
aiming post-ET-myelofibrosis exclusion, along with bone marrow flow cytometry, cytogenetic
and molecular genetic testing.
Results: The patient currently presented with fever, weight loss, night sweats. The performed
laboratory tests showed leukocytosis-81.7 x 109/L, hemoglobin (Hb) increase-160g/l,
hematocrit increase-61%, low platelet count -33 x 109/L. The differential blood count revealed
extreme erythroblastosis with small polychromatic and orthochromatic erythroblasts,
accounting 90% of the peripheral nucleated cells. Serum erythropoietin level was markedly
decreased- 3,3 mU/ml (4.3-32.9). The bone marrow aspirate morphology demonstrated
hypercellularity with 75% erythroblast population and 30% of the granulocytic cell lineage
were myeloblasts. The flow cytometric analysis detected 80% erythroblasts -CD71/+/,
CD36/+/CD45/-/, of which 5% are proerythroblasts and myeloblasts, representing 28% of the
granulocytic cell lineage. The bone marrow biopsy rejected post ET-myelofibrotic progression.
Molecular genetic tests reconfirmed homozygous carriage of mutation V617F of JAK2-gene,
without additional clonal aberrations, while the cytogenetic analysis showed a complex
karyotype. The patient refused active treatment and had a fatal outcome in few weeks.
Conclusions: ET is a disease with an indolent course and favorable prognosis. The leukemic
progression is an uncommon and late complication and the reported in the scientific literature
survival of the cases with transformation varies between 2 and 18 months. In general, the
outcome of patients with either type of acute erythroleukemia is poor with most patients
experiencing an aggressive course. The described case is a point of interest on account of the
combination between unusual morphological presentation, Hb rise and extreme peripheral
eythroblastosis in the course of clinical progression of the disease.