ABSTRACT
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.
Subject(s)
Humans , Female , Infant , Child, Preschool , Child , Adolescent , World Health Organization , Leukemia, Erythroblastic, Acute/classification , Leukemia, Erythroblastic, Acute/diagnosis , Argentina , Leukemia, Erythroblastic, Acute/therapy , Retrospective Studies , Treatment Outcome , Practice Guidelines as Topic , Disease Progression , Cytogenetic Analysis/methods , Flow Cytometry/methodsABSTRACT
Os aspectos epidemiológicos, clínicos, hematológicos e anatomopatológicos da leucemia eritroide aguda (LMA M6) foram estudados em 10 gatos que morreram em consequência dessa condição. Os resultados obtidos diferem daqueles previamente descritos na literatura nos seguintes aspectos: 1) a doença ocorreu na forma de um modelo bimodal relacionado à idade dos gatos afetados, em que 50 por cento tinham 1-3 anos de idade e 50 por cento tinham 10 anos de idade ou mais; 2) quase todos os gatos afetados (87,5 por cento) demonstravam policromasia, possivelmente decorrente de eritropoese extramedular; 3) em todos os casos havia múltiplos focos de células hematopoéticas, principalmente eritropoeticas, em múltiplos órgãos, que incluíam baço (85,7 por cento), linfonodos (71,4 por cento), fígado (57,1 por cento) e rim (28,6 por cento); 4) em alguns casos (28,6 por cento) esses focos podiam ser vistos macroscopicamente, na forma de metástases, mas sempre diferiam histologicamente da medula óssea quanto à proporção dos precursores eritroides envolvidos; 5) em pelo menos um caso ocorreu um continuum patologicum até outra forma de LMA (LMA M4), um fenômeno denominado "infidelidade de linhagem". Esse artigo discute essas diferenças e reforça os critérios fundamentais para se estabelecer o diagnóstico definitivo dessa que é a forma mais importante de leucemia em gatos na nossa região.
The epidemiological, clinical, hematological, and pathological aspects of acute erythroid leukemia (LMA M6) were studied in 10 cats that died from this condition. The results obtained in the present study differ from those previously described in the literature regarding the following aspects: 1) The disease occurred as a bimodal model related to the age of affected cats, in which 50 percent were1-3-years-old and 50 percent were 10 years-old or above; 2) almost all affected cats (87.5 percent) displayed polychromasia, possible resulting from extramedullar erythropoiesis; 3) in all cases there were multiple foci of hematopoietic cells, mainly erythropoietic, in multiple organs including spleen (85.7 percent), lymph nodes (71.4 percent), liver (57.1 percent), and kidney (28.6 percent); 4) in some cases (28.6 percent) these foci could be observed on gross examination as metastasis, but they always histologically differ from bone marrow in regard to the proportion of erythroid precursors involved; 5) at least in one case a continuum patologicum occurred with the condition evolving to another form of LMA (LMA M4), a phenomenon coined as "lineage infidelity". This paper discuss these differences and stresses the fundamental criteria to establish a definitive diagnosis of this condition, which is the most import form of leukemia in cats from our region.