RESUMEN
A 3-year-old female was diagnosed with acute myeloid leukemia (AML-M2). The disease was refractory to various chemotherapeutic agents. Cytogenetic analysis revealed a clone with trisomy 8 at diagnosis that was replaced by a clone containing a t(11;15) and del(20q) by the end of the second induction. A new clone, characterized by a Philadelphia chromosome, with the minor BCR/ABL p190 transcript, emerged 14 months after diagnosis and remained to the end of disease course. The late occurrence of the Philadelphia chromosome in AML has been documented rarely in adults.
Asunto(s)
Leucemia Mieloide Aguda/genética , Cromosoma Filadelfia , Crisis Blástica , Preescolar , Cromosomas Humanos Par 11/genética , Cromosomas Humanos Par 15/genética , Cromosomas Humanos Par 20/genética , Cromosomas Humanos Par 8/genética , Femenino , Proteínas de Fusión bcr-abl/genética , Humanos , Inmunofenotipificación , Hibridación Fluorescente in Situ , Cariotipificación , Leucemia Mieloide Aguda/patología , Leucemia Mieloide Aguda/terapia , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Translocación Genética , TrisomíaRESUMEN
We report an unusual case of T-cell blast crisis of chronic myelogenous leukemia (CML) with a clinical presentation more typical of de novo T-cell lymphoblastic lymphoma. The patient was a 32-year-old man who presented with acute superior vena cava syndrome 19 months after an initial diagnosis of CML and 5 months after allogeneic bone marrow transplantation. The tumor was composed of primitive lymphoid cells expressing CD2, CD3, CD4, CD5, CD7, CD8, and CD10. Although the clinical features were more typical of acute lymphoblastic leukemia/lymphoma, fluorescence in situ hybridization analysis showed the bcr-abl fusion gene within blastic tumor cells. This finding confirmed that the mass represented a blastic transformation of CML. We use the unusual features of the current case and the previous reports to suggest that the development of T-cell blast crisis of CML is dependent on the presence of both marrow and extramedullary disease and a mechanism to evade apoptosis.