Eritroleucemias: Recategorización según criterios de la organización mundial de la salud / Erythroleukemias. Recategorization according to the World Health Organization's criteria

La leucemia aguda es la enfermedad oncológica más frecuente en la infancia. La leucemia linfoblástica aguda representa el 75% y la mieloblástica aguda el 25% de ellas. La eritroleucemia es una entidad infrecuente, representando menos del 5% de las leucemias mieloblásticas agudas. Su definición ha variado a lo largo del tiempo. La OMS en 2017 define el subtipo de eritroleucemia cuando el porcentaje de eritroblastos representa el 80% de la celularidad total de la médula ósea. El presente trabajo, de tipo analítico, retrospectivo, tuvo como finalidad revisar los hallazgos de morfología, citometría de flujo, citogenética, respuesta al tratamiento y evolución de los casos previamente definidos como eritroleucemia, en nuestro centro, en los últimos 25 años y reclasificar aquellos que no cumplían con los nuevos criterios de la OMS 2017. Entre enero de 1990 y diciembre de 2015, se diagnosticaron 576 casos de leucemia mieloblástica aguda siendo 11 (1.9%) de ellos clasificados como eritroleucemia. Resultaron evaluables 10 casos. La distribución por sexo fue 1:1 y la edad mediana fue 5 (rango: 0.9-14) años. Seis pacientes presentaban antecedentes de síndrome mielodisplásico. Según los nuevos criterios, ninguno de los casos analizados puede ser actualmente definido como eritroleucemia. De acuerdo a la recategorización, fueron definidos como leucemias de subtipos de mal pronóstico, como leucemia aguda indiferenciada, sin diferenciación y megacarioblástica. Solo dos pacientes se encuentran libres de enfermedad, probablemente debido a estos subtipos desfavorables, sumado al antecedente frecuente de mielodisplasia.

Acute leukemia is the most frequent malignant disease in childhood. Acute lymphoblastic leukemia represents 75% and acute myeloblastic leukemia 25% of them. Erythroleukemia is a rare entity, corresponding to less than 5% of acute myeloblastic leukemia. Its definition has changed over the time. WHO in 2017 defines erythroleukemia when the percentage of erythroblasts represent 80% of the total cellularity of the bone marrow aspirate. This analytical and retrospective study was performed with the aim of reviewing morphology, flow cytometry and cytogenetic features, response to treatment and outcome of cases previously defined as erythroleukemia in our center during the last 25 years and, in addition to reclassify those cases which do not meet the new WHO 2017 criteria. From January 1990 to December 2015, 576 patients were diagnosed as acute myeloblastic leukemia and 11 (1.9%) of them were classified as erythroleukemia. Ten cases were evaluable. Sex distribution was 1:1 and the median age at diagnosis was 5 (range: 0.9-14) years. Six of them had presented with previous myelodysplastic syndrome. None of the analyzed cases can be currently defined as erythroleukemia, according to the new criteria. When reclassified, the cases were defined as leukemias of subsets with poor prognosis such as acute undifferentiated leukemia, without differentiation and megakaryoblastic leukemia. Only 2 patients remain leukemia-free and this could be explained both by the unfavorable prognosis of these leukemia subtypes, and the antecedent of myelodysplastic syndrome in most of the cases.

Erythroleukemia Relapsing as Precursor B-cell Lymphoblastic Leukemia / 대한진단검사의학회지

AML relapsing as ALL has rarely been reported. We describe the case of a 62-yr-old man who was diagnosed with erythroleukemia with a complex karyotype and achieved complete hematologic and cytogenetic remission after induction chemotherapy. However, 4 months after the initial diagnosis, he showed relapse with blasts showing a different morphology and immunophenotype and was diagnosed with precursor B-cell ALL. The relapsing precursor B-cell ALL presented with the same leukemic clones as the primary erythroleukemia. Cytogenetic analysis of his bone marrow (BM) at the time of the primary erythroleukemia showed complex karyotypic abnormalities, including monosomy 5 and monosomy 7. At relapse, his BM showed reemergence of these leukemic clones of complex karyotypic abnormalities with clonal switch. To our knowledge, this is the first case of a lineage switch from erythroleukemia to ALL.

RAEB-t in young adults--a rare entity.

Refractory anemia with excess blasts in transformation (RAEB-t) in young adults is a rare entity. RAEB-t presenting with megaloblastic erythropoiesis should be differentiated from nutritional B12 and folic acid deficiency and from acute erythroleukemia. We report two cases in the present article.

Atypical presentation of vitamin B12 deficiency mimicking erythroleukaemia in a patient with beta-thalassaemia trait

A 47 year-old patient with vitamin B12 deficiency and beta-thalassaemia trait is presented. A referring diagnosis of erythroleukaemia had been made. At admission the haemoglobin was 72 g/l; haematocrit,.221; mean corpuscular volume [MCV], 91.4 fl; white blood cell count, 2.6 x 109/l and platelet count, 68 x 109/l. Haemoglobin studies showed: haemoglobin A2 4.9% and haemoglobin F, 6.8% concentration. Bone marrow examination showed erythroid hyperplasia with severe dyserythropoiesis and increased immature cells resembling megaloblasts. Three months after treatment with vitamin B12 the pancytopenia resolved and the red blood cells showed microcytosis: haemoglobin, 158 g/l; haematocrit,.489, MCV, 67. 6fl; white blood cell count, 6.1 x 109/l; and platelet count, 384x 109/1. The levels of haemoglobin A2 and F remained elevated six months post-treatment. Two particular aspects are outlined: the absence of typical macrocytic anaemia when vitamin B12 deficiency is combined with thalassaemia trait and the need to rule out folate/vitamin B12 deficiency before establishing a diagnosis of haematopoietic malignancy with dyserythropoiesis such as erythroleukaemia