Utilidad diagnóstica de la biopsia de médula ósea en pediatría / Diagnostic utility of biopsy of bone marrow in Pediatry

La biopsia de médula ósea (BMO) es un procedimiento invasivo que ha ganado campo en la práctica médica ya que se realiza para el diagnóstico, estadificación y seguimiento de enfermedades hematológicas y no hematológicas, benignas o neoplásicas, entre otros. El objetivo fue establecer el rol de la BMO en las hemopatías en Pediatría en el ION SOLCA Guayaquil- Ecuador. Se utilizó un estudio descriptivo retrospectivo donde se incluyeron a todos los pacientes pediátricos menores de 18 años de edad que se sometieron a BMO, desde Julio de 2014 a Julio de 2017 en el hospital. De las 1511 BMO realizadas en el periodo de estudio, 869 correspondieron a biopsias pediátricas, de las cuales el 57,08% fueron varones. La edad mediana fue 5 (RIC: 3-10) años. El tamaño promedio de la BMO fue de 0,74 (0,1-2,5) cm, con una celularidad media de 20% (4-100%). El motivo de consulta más frecuente fue la fiebre (22,67%). En el hemograma se detectó más frecuentemente bicitopenia (44,65%) y pancitopenia (24,63%). La Leucemia Linfoblástica Aguda (LLA) fue la enfermedad hematológica maligna más comúnmente encontrada (19,59%). Solo un 0,12% correspondió al grupo de Síndromes Mielodisplásicos (SMD), mientras que un 0,23% fueron Neoplasias Mieloproliferativas (NMP). El 26,93% de las biopsias no fueron aptas para el diagnóstico, el 48,45% se encontraron libres de enfermedad de base. La enfermedad oncohematológica pediátrica más frecuente es la LLA, mientras que los SMD y las NMP son infrecuentes. El rol del patólogo y de la BMO es fundamental en el diagnóstico de las enfermedades hematológicas, siempre en integración con la clínica y los exámenes complementarios.

Bone marrow biopsy (BMB) is an invasive procedure that has gained ground in medical practice since it is performed for the diagnosis, staging and monitoring of hematological and non-hematological, benign or neoplastic diseases, among others. This work aims to establish the role of the BMB in hematological diseases in Pediatrics in the ION SOLCA Guayaquil ­ Ecuador. A non-experimental design study, descriptive type was used, that included all pediatric patients under 18 years of age who submitted a BMB, from July 2014 to July 2017 in the hospital. Of the 1511 BMB performed in the study period, 869 corresponded to pediatric biopsies, of which 57.08% belong to male patients. The median age was 5 (interquartile range: 3 - 10) years. The average size of the BMB was 0.74 (0.1 - 2.5) cm, with an average cellularity of 20% (4 - 100%). The most frequent reason for consultation was fever (22.67%). In the complete blood count, bicytopenia (44.65%) and pancytopenia (24.63%) were detected most commonly. Acute Lymphoblastic Leukemia (ALL) was the most frequent malignant hematologic disease (19.59%). Only 0.12% corresponded to the group of Myelodysplastic Syndromes (MDS), while 0.23% were Myeloproliferative Neoplasms (MPN). 26.93% of the biopsies were not apt for diagnosis, 48.45% were free of base disease. The most cfrequent pediatric onco-hematologic disease is ALL, while MDS and MPN are infrequent. The role of the pathologist and the BMP is fundamental in the diagnosis of hematological diseases, always in integration with the clinic and complementary examinations.

Estimation of Second Primary Cancer Risk After Treatment with Radioactive Iodine for Differentiated Thyroid Carcinoma.

BACKGROUND: An increase in the incidence of second primary cancers is the late effect of greatest concern that could occur in differentiated thyroid carcinoma (DTC) patients treated with radioactive iodine (RAI). The decision to treat a patient with RAI should therefore incorporate a careful risk-benefit analysis. The objective of this work was to adapt the risk-estimation models developed by the Biological Effects of Ionizing Radiation Committee to local epidemiological characteristics in order to assess the carcinogenesis risk from radiation in a population of Brazilian DTC patients treated with RAI. Absorbed radiation doses in critical organs were also estimated to determine whether they exceeded the thresholds for deterministic effects. METHODS: A total of 416 DTC patients treated with RAI were retrospectively studied. Four organs were selected for absorbed dose estimation and subsequent calculation of carcinogenic risk: the kidney, stomach, salivary glands, and bone marrow. Absorbed doses were calculated by dose factors (absorbed dose per unit activity administered) previously established and based on standard human models. The lifetime attributable risk (LAR) of incidence of cancer as a function of age, sex, and organ-specific dose was estimated, relating it to the activity of RAI administered in the initial treatment. RESULTS: The salivary glands received the greatest absorbed doses of radiation, followed by the stomach, kidney, and bone marrow. None of these, however, surpassed the threshold for deterministic effects for a single administration of RAI. Younger patients received the same level of absorbed dose in the critical organs as older patients did. The lifetime attributable risk for stomach cancer incidence was by far the highest, followed in descending order by salivary-gland cancer, leukemia, and kidney cancer. CONCLUSION: RAI in a single administration is safe in terms of deterministic effects because even high-administered activities do not result in absorbed doses that exceed the thresholds for significant tissue reactions. The Biological Effects of Ionizing Radiation Committee mathematical models are a practical method of quantifying the risks of a second primary cancer, demonstrating a marked decrease in risk for younger patients with the administration of lower RAI activities and suggesting that only the smallest activities necessary to promote an effective ablation should be administered in low-risk DTC patients.