RESUMO
Chronic myeloproliferative neoplasms (MPN) are clonal disorders of hematopoietic stem cells, which fall into distinct categories based on a number of characteristics including the presence of the BCR-ABL1 gene fusion (chronic myelogenous leukemia) or the JAK2(V617F) mutation (polycythemia vera, primary myelofibrosis, and essential thrombocythemia). One of the criteria in the 2008 World Health Organization Classification divides MPN into different categories based on the presence of an underlying genetic abnormality, however the WHO does not currently address the classification of myeloproliferative neoplasms that have more than one genetic abnormality. The coexistence of a JAK2(V617F) mutation and BCR-ABL1 is rare, and to our knowledge, less than 25 cases have been reported in the literature. Our case series examines the clinical, histopathologic, and genetic features of 3 patients with myeloproliferative neoplasms characterized by concomitant BCR-ABL1 and JAK2(V617F). The implications for diagnosis and treatment of patients with concomitant BCR-ABL1 and JAK2(V617F) are discussed as well as how the BCR-ABL1 and JAK2(V617F)-positive clones may be related to one another.
Assuntos
Proteínas de Fusão bcr-abl/genética , Janus Quinase 2/genética , Transtornos Mieloproliferativos/genética , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Transtornos Mieloproliferativos/complicações , Transtornos Mieloproliferativos/diagnóstico , Translocação GenéticaRESUMO
Aggressive histiocytic lesions are uncommon in the pediatric population. These neoplasms occur in isolation or after therapy for other types of hematopoietic malignancy such as T-cell acute lymphoblastic leukemia. The etiology of these lesions is poorly understood, and no definitive standard of care has been established for patients with these diagnoses. Here, we report the success of thalidomide treatment for 2 subtypes of histiocytic proliferation--metastatic histiocytic sarcoma and extracutaneous juvenile xanthogranuloma--in pediatric patients. Our findings highlight the importance of considering thalidomide therapy in this unique and difficult to treat patient population.
