Submitting Author: Roshal, MIkhail, MD, PhD
Institution: Weill Cornell Medical College
Additional authors:Yen-Chun Liu M.D., Wayne Tam M.D. PhD, Attilio Orazi M.D.
Session: AML with recurrent genetic abnormalities Part I

35 year old male presenting with 3 weeks of non-specific symptoms found to have anemia, thrombocytopenia and 3% blasts in the peripheral blood. At the time of diagnosis patient had WBC of 9.8 thousand/ul, Hemoglobin of 10.5 g/dl and platelets 30 thousand per/ul , MCV was 105 fL. Patient was diagnosed with AML. On physical exam the patient had hepatomegaly. Patient was treated with double induction with daunorubicin and AraC without achieving morphologic remission (marrow blasts 10% and underwent salvage therapy with high dose cytarabine without morphologic response. He underwent myeloablative allogeneic stem cell transplant from an unrelated donor and achieved transient morphologic remission, but relapsed by day 100 post transplant and received a second transplant with rapid relapse of the disease. Patient succumbed to the disease shortly thereafter

Right PIC, Biopsy, clot section, aspirate and peripheral blood.

Peripheral blood showed anemia, thrombocytopenia with occasional giant platelets and 3% blasts. Immature monocytic forms were also detected.

The bone marrow was markedly hypercellular (95%). The marrow cellularity consisted mostly of a diffuse proliferation of blasts, with round

to irregular nuclei, finely dispersed chromatin and moderately

abundant cytoplasm. Maturing granulopoiesis and erythropoiesis was markedly decreased. Monocytes were increased. In addition, increased atypical megakaryocytes were scattered throughout the marrow. These

megakaryocytes were very small with monolobated or bilobated

nuclei A reticulin stain showed a mild increase (1+) in reticulin

fibers.

Flow cytometry sample was hemodilute. It demonstrated an expanded CD34 and CD117 positive blast population of CD4, CD11b, CD13(dim), CD15, CD33 and HLA-DR (low). In addition atypical monocytic cells expressing CD14, CD15, CD33, CD64 and CD41 without HLA-DR were found

Cytogentics demonstrated 46, XY, inv(3)(q21q26.2)[20] without further abnormalities

FLT3 and NPM mutations were not detected

This case demonstrates a typical presentation, morphologic features and clinical behavior of acute myeleoid leukemia with inv(3)(q21;q26.2). This is relatively rare entity representing 1-2% of AML has aggressive clinical behavior and poor response to therapy. Typical features that are well illustrated in the case include striking megakaryocyte dysplasia and numerous giant platelets in the peripheral blood. The case also reports immunophenotypic findings which have been relatively sparse in the literature

Acute myeloid leukemia with inv(3)(q21;q26.2)

Case 293