Submitting Author: Bakshi, Nasir Ahmed, MD
Institution: KFSH & RC
Additional authors:Tarek M Owaidah, MD
Session: Erythroleukemia and megakaryoblastic AML and mimics

A 20–year-old male was referred with Coombs’ negative hemolytic anemia. His initial complaints were easy fatigability and jaundice, which was noticed by his friends. Physical examination was unremarkable except for mild jaundice. No significant history of past illness; family history was negative for any hematological disorders. Laboratory findings showed WBC 4.58 x 109/L, RBC 2.13 x 1012/L, HGB 73 g/L, HCT 0.230, MCV 108.0 fL, MCH 34.3 pg, MCHC 317 g/L, RDW 18.6%, retculocytes 9%, LDH 927 U/L, G6PD was normal, negative for sickle cells, Platelet count 20 x 109/L. Plasma free hemoglobin was as high as 0.65 (normal range <0.05g/L) His haptoglobin was very low (less than 0.07g/L). Bilirubin was 77mmol/L, mostly indirect (92% of total bilirubin).

Peripheral blood smear showed moderate anisopoikilocytosis with macrocytes, macroovalocytes, teardrop cells, spur cells, red cell fragments and spherocytes. There was moderate polychromasia and many NRBCs were noted. Circulating immature cells were noted consistent with blasts (4%). Platelets decreased with some larger forms. No platelet clumps noted.

Bone marrow aspirate showed remarkable erythroid hyperplasia with all stages of development being present, earlier forms predominating. There was megaloblastosis, nuclear/cytoplasmic asynchrony and moderate to severe dysplasia in the form of multinucleation, irregular nuclear outlines and nuclear budding. The erythroid precursors altogether consitituted ~72% of nucleated cells on the aspirate (M:E ratio of 1 : 3.5). Non-erythroid blasts comprised ~9% of the total nucleated cells on the smear (~30% of non-erythroid cells). Some of these blasts showed single to multiple thin/slender Auer rods. Slight left shift of the myeloid series with mild dysplastic changes noted in granulocytes. Megakaryocytes are decreased in smear and only rarely identified on the aspirate.

Trephine revealed 90% cellularity with marked erythroid hyperplasia, with many immature forms of erythroid/myeloid series present showing high N/C ratio, fine chromatin and prominent nucleoli. Megakaryocytes were significantly decreased on the biopsy.

Flow immunophenotyping showed ~6% myeloblasts co-expressing CD4 (dim), CD13, CD19 (dim), CD33, CD117, HLA-DR and myeloperoxidase. CD34 was negative.

46, XY

FISH PANEL FOR MLL, del 5, del 7, t(8;21), t(15;17), Trisomy 8: Negative

Negative

Hemolysis as a presenting feature in leukemia is very rare and exclusively autoimmune. This case is quite unusual in that the presenting feature was nonimmune hemolysis and only after bone marrow examination was confirmed to be acute erythroleukemia with normal karyotype.

Acute erythroid/myeloid leukemia (AML-M6) with non-immune hemolysis

Refractory anemia with excess blasts - 2 (RAEB-2), with concomittant hemolysis contributing to erythroid hyperplasia

Case 352