ABSTRACT
La leucemia mieloide crónica (LMC) representa el 3% de las leucemias pediátricas diagnosticadas y su incidencia es de 0,7 millones por año, extremadamente rara entre las edades de 1 a 14 años y debido a esta inusual presentación existen pocos casos descritos. La patogénesis molecular de la LMC implica la fusión quimérica de la proteína BCR-ABL, cuyo aumento constitutivo de la actividad tirosina quinasa, contribuido por el componente ABL, parece ser el causante de la alteración molecular en la LMC. La identificación de esta proteína quimérica resultó en el desarrollo exitoso del mesilato de imatinib, fármaco que ha revolucionado el tratamiento de esta enfermedad. El tratamiento con imatinib en niños ha logrado alcanzar un 90% de remisión completa a los 5 años, sustituyendo de esta manera al trasplante alogénico como primera línea de terapia. A continuación reportamos el caso de un niño de 2 años cuyo hemograma reportó: anemia microcítica moderada (hemoglobina de 11,7 g%), hiperleucocitosis (leucocitos 80,8 x10(9)/L), y trombocitosis (721x10(9)/L). Los estudios de citogenética, FISH y RT-PCR para BCR-ABL1 dieron positivos, confirmando el diagnóstico de LMC en fase crónica. Se inició inmediatamente el tratamiento con imatinib y a 3 años del diagnóstico el paciente se encuentra en remisión completa a nivel molecular, con ausencia del clon neoplásico y sin haber presentado efectos colaterales adversos de importancia.
Chronic myeloid leukemia (CML) accounts for 3% of all diagnosed pediatric leukemias. It has an incidence of 0.7 million per year, rarely diagnosed between the ages of 1 to 14 years, so few cases have been reported. The CML molecular pathogenesis involves a chimeric fusion of the BCR-ABL protein which increased constitutive tyrosine kinase activity contributed by ABL component seems to be the cause of the molecular alteration in CML. The identification of this chimeric protein resulted in the successful development of imatinib mesylate, a drug that has revolutionized the treatment of this disease. The use of imatinib in children has reached 90% of complete remission at 5 years, replacing in this way the allogeneic transplant as first-line therapy. This report presents the case of a 2 year old child whose CBC reported: moderate microcytic anemia (hemoglobin 11.7 g%), hyperleukocytosis (leukocytes 80.8 x10(9)/L) and thrombocytosis (721x10(9)/ L). Cytogenetic, FISH and RT-PCR Studies for BCR-ABL1 were positive, confirming the diagnosis of CML in chronic phase. Treatment with imatinib was initiated immediately and 3 years after diagnosis the patient is in complete molecular remission with the absence of neoplastic clone and without having presented significant side effects.
Subject(s)
Humans , Child, Preschool , Leukemia, Myelogenous, Chronic, BCR-ABL Positive , Leukemia , Leukemia, Myeloid/drug therapy , Leukemia/diagnostic imagingABSTRACT
Whole-body magnetic resonance imaging (MRI) is increasingly used in children to evaluate the extent and distribution of various neoplastic and non-neoplastic diseases. Not using ionizing radiation is a major advantage of pediatric whole-body MRI. Coronal and sagittal short tau inversion recovery imaging is most commonly used as the fundamental whole-body MRI protocol. Diffusion-weighted imaging and Dixon-based imaging, which has been recently incorporated into whole-body MRI, are promising pulse sequences, particularly for pediatric oncology. Other pulse sequences may be added to increase diagnostic capability of whole-body MRI. Of importance, the overall whole-body MRI examination time should be less than 30-60 minutes in children, regardless of the imaging protocol. Established and potentially useful clinical applications of pediatric whole-body MRI are described.