Leucemia Mielóide Aguda t(8; 21) após tratamento de hipertiroidismo com iodo radioativo: Leucemia secundária? / Acute Myeloid Leukemia t(8; 21) after treatment for hyperthyroidism using radioactive iodine: Secondary Leukemia?

Acute leukemia following treatment with Iodine131 is a rare event. The possible carcinogenic effect of Iodine131 is still not clear and a large series of cases did not show an increased incidence of cancer. A case of AML t(8;21), three years after Iodine131 treatment for hyperthyroidism, is reported. Secondary AML with t(8;21) is described following exposure to drugs that target topoisomerase II and radiotherapy. The controversial potential of Iodine131 as a leukemogenic agent and the fact that t(8;21) is also found in de-novo AML, emphasize the problem in establishing a relationship between these events although this potential can not be ruled out.

Myelodysplastic syndromes: histopathology as prognostic factor

Bone marrow biopsy allows evaluation of cellularity, abnormal localization of immature precursors and fibrosis in myelodysplastic syndrome. It has been considered important to make diagnosis and prognosis of this disorder. The object of this study evaluated the influence of histopathological parameters, such as cellularity, erythroid/myeloid ratio, abnormal localization of immature precursors and marrow fibrosis, on survival of myelodysplastic syndrome patients. Forty-six patients, admitted from April 1985 to June 1998, and diagnosed as being myelodysplastic syndrome according to French-American-British criteria, were selected. There were 20 males and 26 females, with median age of 61 years. Forty-six bone marrow smears and 36 trephine biopsies were reviewed. Mean survival of hypocellular cases was 64.8 months and of hyper and normocellular cases was 31.8 months. Patients with predominance of erythroid hyperplasia had mean survival of 50.8 months, greater than those with predominance of myeloid hyperplasia (20.3 months). There was no statistical difference in survival of patients with or without abnormal localization of immature precursors and with or without marrow fibrosis. Bone marrow biopsy is a useful tool for the identification of parameters that influence prognosis in myelodysplastic syndrome. Hypocellularity and erythroid hyperplasia were correlated with longer survival while myeloid hyperplasia with poorer survival

A biópsia de medula óssea propicia a avaliação da celularidade global, dos precursores imaturos de localização anormal e de fibrose nas sídromes mielodisplásicas. O método tem sido considerado importante também para o diagnóstico e prognóstico da síndrome. O objetivo deste estudo foi o de o observar a influência de parâmetros histológicos como a celularidade, a relação eritróide mielóide, a presença de precursores imaturos de localização anormal e fibrose medular na sobrevida de pacients com a síndrome. De abril de 1985 a junho de 1998, 46 pacientes diagnosticados segundo os critérios do grupo Franco, Americano, Britânico foram estudados. A casuística era composta de 20 pacientes do sexo masculino e de 26 do sexo feminino com idade média de 61 anos. Foram revisados 46 esfregaços de aspirado de medula óssea e 36 cortes histológicos de bioópsia de medula óssea. A sobrevida média dos casos de hipocelularidade foi de 64,8 meses e dos casos que eram hiper ou normocelulares foi de 31,8 meses. Pacientes com a predominância de hiperplasia tiveram sobrevida média de 50,8 meses, que foi superior aos que apresentavam hiperplasia mielóide (20,3 meses). Não houve diferença estatística na sobrevida dos pacientes que apresentaram ou não fibrose medular. A biópsia de medula óssea deve ser considerada útil na identificação de prâmetros que influenciam no prognóstico da síndrome mielodisplásica. A hipocelularidade e a hiperplasia eritrocitária está realcionada com a sobrevida maior, enquanto a hiperplasia mielóide com a sobrevida mais curta.