a 48 years old saudi male presented to the emergency department with shortness of breath , persistent low grade fever and easy bruising for 3 days . the patient also complained of progressive weakness , loss of appetite for 2 months duration and had lost 7 kg of weight over the last 2 months . his family or medical history was unremarkable and was not receiving any medical treatment for any chronic illness . he was a heavy smoker consuming two packs of cigarettes daily for several years and had long history of heavy alcohol abuse . he denied any drug abuse or toxin exposure . on physical examination ; he was pale , had multiple bruises particularly on the lower limbs and his body temperature was 38.2c . g / l ) , red blood cells ( rbc ) 2.1510/l ( 4.2 - 5.510/l ) , mean corpuscular volume 88 fl ( 78 - 97 fl ) and mean corpuscular hemoglobin 28 pg ( 27 - 32 pg ) . leukocytes were 2.0110/l with 3% blasts , myelocytes 3% , neutrophils 19% , monocytes 8% , basophils 1% and 67% lymphocytes . biochemical markers revealed elevated serum levels of lactate dehydrogenase ( ldh ) , uric acid and total bilirubin . peripheral smear showed marked anisopoikilocytosis with schistocytes , basophilic stippling , spherocytes , many nucleated rbc and rare circulating blasts . erythroid precursors showed significant dysplastic changes with nuclear irregularities , budding and bi - nucleation while neutrophil morphology was essentially normal . the circulating blasts were medium to large blasts with round nuclei , fine chromatin , prominent nucleoli and deep blue a granular cytoplasm without auer rods . the bone marrow aspirate yielded a markedly hypercellular bone marrow essentially replaced by erythroid precursors , representing approximately 87% of the marrow cells . the erythroid precursors displayed dysplastic morphology , including multi - nucleation , nuclear budding and megaloblastoid changes . periodic acid schiff ( pas ) stain revealed globular and block - like positivity in many abnormal erythroblasts . perls perl s stain showed a few sideroblasts ; however no ringed sideroblasts were observed . flow cytometry analysis of the bone marrow aspirate revealed many immature cells which were positive for cd71 , glycophorin a and partially positive for cd36 , consistent with erythroid precursors . staining for cd13 , cd33 , cd34 , cd41 , cd61 and all other myeloid and lymphoid makers was negative . the bone marrow biopsy revealed a hypercellular packed marrow with monotonous leukemic infiltrate composed of primitive looking blasts . the infiltrating blasts had scant cytoplasm , high nuclear to cytoplasmic ratio , round nucleus with fine chromatin and 1 - 2 prominent nucleoli ( figure 1 ) . immunohistochemistry revealed strong positivity to e - cadherin ( ech-6 ; ventana medical systems , inc . , roche , basel , switzerland ) , weak positivity for glycophorin a ( ga - r2 ; ventana medical systems , inc . ) and negative for cd34 , mpo , vwf , cd3 and cd79a . these morphological and immunophenotypic findings supported the diagnosis of pure erythroid leukemia ( pel ) fab subtype m6b . cytogenetics analysis was performed on 20 metaphases and detected a complex karyotype with multiple chromosomal aberrations ( figure 2 ) : 
 46 - 48,xy , add(4)(q ? ) del(4)(p?),del(5)(q23),add(6)(p 23),del(7)(q22 ) , t(8;9)(p11.2;q12),+del(9)(q22),de l(18)(q21 ) the patient was treated with a standard induction ( 7 + 3 ) chemotherapy regimen consisting of daunorubicin 45 mg / m daily for 3 days and cytarabine 100 mg / m daily continuous infusion for 7 days . blood and platelet transfusions were administered during induction period . on post - induction day 28 , the bone marrow biopsy showed hypercellular marrow with 38% residual erythroblasts . he was re - inducted again with flag regimen ( fludarabine + high - dose cytarabine + g - csf ) . he failed to tolerate the treatment and died after 10 days due to severe pulmonary infection . a 48 years old saudi male presented to the emergency department with shortness of breath , persistent low grade fever and easy bruising for 3 days . the patient also complained of progressive weakness , loss of appetite for 2 months duration and had lost 7 kg of weight over the last 2 months . his family or medical history was unremarkable and was not receiving any medical treatment for any chronic illness . he was a heavy smoker consuming two packs of cigarettes daily for several years and had long history of heavy alcohol abuse . he denied any drug abuse or toxin exposure . on physical examination ; he was pale , had multiple bruises particularly on the lower limbs and his body temperature was 38.2c . g / l ) , red blood cells ( rbc ) 2.1510/l ( 4.2 - 5.510/l ) , mean corpuscular volume 88 fl ( 78 - 97 fl ) and mean corpuscular hemoglobin 28 pg ( 27 - 32 pg ) . leukocytes were 2.0110/l with 3% blasts , myelocytes 3% , neutrophils 19% , monocytes 8% , basophils 1% and 67% lymphocytes . platelet count was 2310/l ( 140 - 45010/l ) . biochemical markers revealed elevated serum levels of lactate dehydrogenase ( ldh ) , uric acid and total bilirubin . peripheral smear showed marked anisopoikilocytosis with schistocytes , basophilic stippling , spherocytes , many nucleated rbc and rare circulating blasts . erythroid precursors showed significant dysplastic changes with nuclear irregularities , budding and bi - nucleation while neutrophil morphology was essentially normal . the circulating blasts were medium to large blasts with round nuclei , fine chromatin , prominent nucleoli and deep blue a granular cytoplasm without auer rods . the bone marrow aspirate yielded a markedly hypercellular bone marrow essentially replaced by erythroid precursors , representing approximately 87% of the marrow cells . the erythroid precursors displayed dysplastic morphology , including multi - nucleation , nuclear budding and megaloblastoid changes . periodic acid schiff ( pas ) stain revealed globular and block - like positivity in many abnormal erythroblasts . perls perl s stain showed a few sideroblasts ; however no ringed sideroblasts were observed . flow cytometry analysis of the bone marrow aspirate revealed many immature cells which were positive for cd71 , glycophorin a and partially positive for cd36 , consistent with erythroid precursors . staining for cd13 , cd33 , cd34 , cd41 , cd61 and the bone marrow biopsy revealed a hypercellular packed marrow with monotonous leukemic infiltrate composed of primitive looking blasts . the infiltrating blasts had scant cytoplasm , high nuclear to cytoplasmic ratio , round nucleus with fine chromatin and 1 - 2 prominent nucleoli ( figure 1 ) . immunohistochemistry revealed strong positivity to e - cadherin ( ech-6 ; ventana medical systems , inc . , roche , basel , switzerland ) , weak positivity for glycophorin a ( ga - r2 ; ventana medical systems , inc . ) and negative for cd34 , mpo , vwf , cd3 and cd79a . these morphological and immunophenotypic findings supported the diagnosis of pure erythroid leukemia ( pel ) fab subtype m6b . cytogenetics analysis was performed on 20 metaphases and detected a complex karyotype with multiple chromosomal aberrations ( figure 2 ) : 
 46 - 48,xy , add(4)(q ? ) del(4)(p?),del(5)(q23),add(6)(p 23),del(7)(q22 ) , t(8;9)(p11.2;q12),+del(9)(q22),de l(18)(q21 ) the patient was treated with a standard induction ( 7 + 3 ) chemotherapy regimen consisting of daunorubicin 45 mg / m daily for 3 days and cytarabine 100 mg / m daily continuous infusion for 7 days . blood and he was re - inducted again with flag regimen ( fludarabine + high - dose cytarabine + g - csf ) . he failed to tolerate the treatment and died after 10 days due to severe pulmonary infection . pure erythroid leukemia is exceedingly rare type of aml representing < 1% of all aml cases and 13% of acute erythroid leukemia cases . it is a neoplastic proliferation of immature cells committed exclusively to the erythroid lineage comprising at least 80% of bone marrow cells with no evidence of a significant myeloblastic component . clinically , pel patients present usually with profound anemia symptoms such as weakness and pallor , fever and hemorrhages . there are few reported cases of extramedullary pure erythroid leukemia involving lymph nodes or presenting as a hemangioma . our patient presented with pel post heavy alcohol abuse over a prolonged time period that may indicate presence of some kind of causal relationship , an observation consistent with previous reports . because of the extreme rarity of pel , few studies have examined its pathogenesis and genetic features . . however , rare cases of de novo familial pel , being autosomal dominant , have been reported . a number of available studies have revealed complex karyotype with predominance of -5/del(5q ) , -7/del(7q ) and + 19p . in a study conducted by liu et al . , all pel patients ( n=16 ) showed an extremely complex karyotype , with a median of 12 abnormalities ( range 3 - 37 ) . these abnormalities most frequently involved chromosomes 5 ( 69% ) , 7 ( 56% ) , 17 ( 44% ) , and 19 ( 38% ) . cytogenetic study for the present patient revealed an extreme complex karyotype with 8 chromosomal abnormalities . beside the most commonly reported abnormalities , such as del(5q ) and del(7q ) , our patient had a novel translocation t(8;9)(p11.2;q12 ) in all the examined metaphases . to the best of our knowledge , this translocation has never been reported in acute myeloid leukemia in the past . unfortunately , we were not able to perform a higher molecular study in order to clarify the origin of this abnormality . diagnosis of pel requires multiparameter approach including detailed clinical history , peripheral blood and bone marrow examination , immunophenotyping and genetic studies as well . the present case also showed pancytopenia with 3% circulating blasts in the peripheral blood . in bone marrow aspirate , the majority of cells ( > 80% ) are erythroid precursors with marked left shift and increased proerythroblasts . proerythroblasts - the most immature recognizable erythroid precursors- are medium to large blasts with round nuclei , fine chromatin , occasional prominent nucleoli , deep blue agranular cytoplasm with variable cytoplasmic vacuolization and no auer rods . periodic acid - schiff ( pas ) cytochemical staining is commonly positive , often in cytoplasmic vacuoles in a block - like pattern , while mpo , sudan black , and chloroacetate esterase are characteristically negative . core biopsy is usually markedly hypercellular and shows erythroid predominance with sheets of immature cells clearly demonstrating a leukemic infiltrative pattern . erythroblasts usually express cd71 ( transferrin receptor ) , but occasionally cd71 expression can be aberrantly dim . these cells variably express hemoglobin a , glycophorin a , abh blood group antigens , and hla - dr . . the gerbich blood group ( gero ) antibody , carbonic anhydrase1 , and cd36 can be expressed by more immature erythroblast . immunophenotyping of the present case revealed many immature cells which were positive for cd71 , glycophorin a and partially positive for cd36 , consistent with erythroid precursors . various markers including glycophorin a , b , and c , hemoglobin , cd36 , and spectrin have been used to identify immature erythroblasts in pel ; however , the results either lack consistency or specificity . e - cadherin is a cell adhesion molecule involved in the morphogenesis of multicellular organisms and maintenance of solid tissues . it is a selective marker of immature erythroblasts and is down regulated during erythroid maturation . in the bone marrow , its expression appears to be limited to erythroid lineage , and mainly in immature erythroblasts . in the present patient , e - cadherin immunohistochemistry stain revealed strong positivity ( 80% ) while glycophorine glycophorin a was weak positive ( 20 ) which was in agreement with the published data . differential diagnosis of pel is broad , and includes both non - neoplastic and neoplastic conditions . erythroid hyperplasia may result from ineffective erythropoiesis such as congenital dyserythropoietic anemia , hemolytic anemia , vitamin b12/folate deficiency , infection , or autoimmune hemolysis . even marked dyserythropoiesis can be seen in floridly reactive conditions potentially mimicking a myeloid neoplasm . pure erythroid leukemia needs also , to be distinguished from other forms of myeloid neoplasms with erythroid predominance namely therapy related ( t - aml ) , acute myeloid leukemia with myelodysplasia related changes ( aml - mrc ) , aml with recurrent cytogenetic abnormalities and myelodysplastic syndrome . cases that do not fit into any of the above well - defined categories are classified as amlnos , further subcategorized by their morphologic and immunophenotypic characteristics . pure erythroid leukemia without morphologic evidence of erythroid maturation may be difficult to be distinguished from other types of aml , particularly megakaryoblastic leukemia , and also from acute lymphoblastic leukemia and lymphoma . the median survival is 3.6 months compared with 28 months in acute erythroid / myeloid leukemia . the standard induction for pel is ( 7 + 3 ) chemotherapy regimen , consisting of daunorubicin 45 mg / m daily for 3 days and cytarabine 100 mg / m daily continuous infusion for 7 days ; which offers a complete remission ( cr ) rate of approximately 10 - 40% ; if cr is obtained , it is usually brief . the response to chemotherapy and the length of survival is dependent on several factors such as cytogenetics and karyotype abnormality and patient comobidities . the median survival is 3.6 months compared with 28 months in acute erythroid / myeloid leukemia . the standard induction for pel is ( 7 + 3 ) chemotherapy regimen , consisting of daunorubicin 45 mg / m daily for 3 days and cytarabine 100 mg / m daily continuous infusion for 7 days ; which offers a complete remission ( cr ) rate of approximately 10 - 40% ; if cr is obtained , it is usually brief . the response to chemotherapy and the length of survival is dependent on several factors such as cytogenetics and karyotype abnormality and patient comobidities .