Submitter(s): Annette H. Schmitt-Graeff, Peter Haas, Michael Luebbert. Clinical history The 67-year old woman presented with micocytic anemia and thrombocythosis. The hemoglobin was 8.7 g/dl, the MCV 79.3 fl, the MCH26.1 pg, the platelets 801 x 109/L. The coombs test was negative. There was no hepatosplenomegaly. Details of gross/microscopic pathology: Bone marrow smears and sections of trephine biopsy showed hyperplastic erythropoiesis with maturation defects and ringed sideroblasts (about 20%) on Pearl's stained aspirates. The megakaryopiesis was strikingly increased with atypical clusters and numerous small megakaryocytes with round nuclear contours. The myeloid series was in the normal range. Siver impregnation showed no reticulin fibrosis. Peripheral blood smears showed a striking anisocytosis. Immunophenotype (flow cytometry/immunohistochemistry): Immunostaining of one marrow sections for hemoglobin confirmed the predominance of erythroid precursors (more then 50% of nucleated cells). Abundant megakaryocytes expressed CD41 and CD61. There was no excess of CD34 precursor/blast cells. Supravitalstaining revealed erythrocyte HbH inclusions. Electron micrographs of bone marrow disclosed tyical mitochondrial iron deposits. Cytogenetics: Normal karyotype. Molecular analysis: JAK2 617F negative Mutation of the ATRX gene (R. Gibbons, Oxford). Interesting feature(s) of submitted case: The bone marrow of this case showed sideroblastic erythropoiesis in association with megakaryocytic proliferation and thrombocythosis. This condition is referred as to refractory anemia with marked thrombocytosis (RARS-T) and combines features of a myelodysplastic syndrome (MDS) with a myeloproliferative disorder (MPD). Most patients with RARS-T have a macrocytic anemia, while this patient presented with microcytic anemia which prompted an investigation for a HbH disease, which has recently described in rare MDS cases. The presence of an acquired thalassemia phenotype in RARS-T provides evidence of an additional dysplastic feature which may occurr in this MDS/MPD overlap syndrome. Proposed diagnosis: Refractory anemia with ringed sideroblasts and thrombocythosis associated with acquired alpha-thalassemia. Panel diagnosis: agree with proposed diagnosis Comments: Panel comment: myelodysplastic features noted. PowerPoint: Presentation Link Images: Back to Top Back to Cases by Session Back to Cases by Contact Submitter |