Outcomes and challenges treating pediatric acute myeloid leukemia: a retrospective analysis of patients treated at the Fundación Valle del Lili between 2011 and 2020.

INTRODUCTION: Acute myeloid leukemia is a challenging disease, due to a poor prognosis in developing countries. Herein, we aim to describe the clinical characteristics and outcomes after chemotherapy and transplantation. METHODS: A retrospective analytic observational study was performed with patients under 18 years of age with newly diagnosed acute myeloid leukemia treated at a referral center in Colombia. Two groups were compared: induction therapy (IT) and induction therapy plus consolidation (IT + C). The survival analysis was performed using the Kaplan-Meier method. RESULTS: We analyzed 34 patients diagnosed with acute myeloid leukemia; 20 received hematopoietic stem cell transplantation. Most were French-American-British (FAB) classification types M1, M5 and M0. The transplantation was haploidentical in 65%, conditioning was myeloablative in 67% and graft-versus-host disease prophylaxis was performed with post-transplant cyclophosphamide in 70%. Overall, the 5-year survival was 52% and the overall 5-year survival in the transplanted group was 80%. There were 16 deaths; in the IT group, n = 12, and in the IT + C group, n = 4. In the former, the main cause of death was septic shock and in the latter, it was relapse. CONCLUSION: Transplantation is a safe option. Receiving treatment and supportive measures in hematopoietic stem cell transplantation units is necessary to avoid infections, especially during induction cycles.

Pediatric hemophagocytic lymphohistiocytosis: A rarely diagnosed entity in a developing country.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is an exaggerated inflammatory reaction secondary to a host's inadequate immune response causing a self-perpetuating loop of altered regulation. Signs and symptoms of HLH are compatible with other common diseases and are nonspecific. Underdiagnosis makes it difficult to estimate the real incidence of HLH, especially in developing countries. METHODS: Retrospective, descriptive study of pediatric patients admitted to a high-complexity institution in Cali, Colombia between 2012 and 2019 with HLH diagnosis. Medical history review to complete an electronic database and a secondary, descriptive analysis was carried out. The study was approved by the Institutional Ethics Committee. RESULTS: Twenty-one patients were included. 52.4 % of the population was male with a median age of 9.3 years [IQR (3.0-13.7 years)]. More than half of patients (66.6 %) had viral disease at diagnosis, the most frequent being Epstein-Barr Virus (EBV) (52.3 %) and dengue (14.3 %). Three patients had confirmed gene mutations (G6PC3, XIAP, and UNC13D). 95 % of the patients were treated with the HLH 2004 protocol, half of them received incomplete protocol with intravenous immunoglobulin (IVIG) and/or systemic steroids, while the other half received the complete protocol including etoposide and cyclosporine. More than three-fourths (76.2 %) required admission to an ICU with a median stay of 14 days [IQR (11-37 days)] and a median hospital stay of 30 days [IQR (18-93 days)]. 14.3 % (n = 3) of patients died. CONCLUSIONS: HLH is a complex disease that requires multidisciplinary management with secondary HLH due to EBV infection being a common cause. There is increasing awareness of HLH diagnosis in developing countries such as Colombia which can offer earlier treatment options and better outcomes.

Hepatoblastoma: Transplant Versus Resection Experience in a Latin American Transplant Center.

BACKGROUND: Hepatoblastoma is the most common primary malignant liver tumor in children and is usually diagnosed during the first 3 years of life. Overall survival has increased 50% due to chemotherapeutic schemes, expertise surgery centers, and liver transplantation. METHODS: A retrospective collection of data was performed from pediatric patients with diagnosis of hepatoblastoma. Variables included demographic, diagnostic tools and histological classification; chemotherapy and surgical treatment; and outcomes and patient survival. The PRETEXT classification was applied, which included the risk evaluation, and according to the medical criterion in an individualized way, underwent resection or transplant. The morbidity of patients was evaluated by the Clavien-Dindo classification. Statistical analysis was performed according to the distribution of data and the survival analysis was carried out using the Kaplan-Meier method. RESULTS: The patients (n = 16) were divided in a resection group (n = 8) and a transplant group (n = 8). The median age at the time of diagnosis was 13.5 months. The motive for the initial consultation was the discovery of a mass; all patients had high levels of α-fetoprotein and an imaging study. Ten of 16 patients required chemotherapy before the surgical procedure. In the resection group, 5 of 8 patients were classified as Clavien I and 4 of 8 patients of the transplant group were classified as Clavien II. Patient survival at 30 months was 100% in the resection group and 65% in the liver transplantation group. CONCLUSIONS: To our knowledge, this is the first case report of pediatric patients with hepatoblastoma and liver resection or transplant in Colombia and Latin America. Our results are comparable with the series worldwide, showing that resection and transplant increase the survival of the pediatric patients with hepatoblastoma. It is important to advocate for an increase of reporting in the scientific literature in Latin America.

Histiocitosis de células de Langerhans en niños. Descripción de 10 casos / Langerhans cell histiocytosis in children. A description of 10 cases

Introducción: la histiocitosis de células de Langerhans constituye una entidad poco frecuente, con diferentes tipos de presentación clínica y patológica, que varían desde unisistémica y unifocal hasta compromiso de múltiples sistemas. Es consecuencia de la proliferación, acúmulo e infiltración en diferentes órganos, de células que hacen parte del sistema fagocítico mononuclear. El objetivo con la descripción de esta serie de casos es la de resaltar la importancia y sensibilizar a un diagnóstico y manejo oportuno de esta entidad, para una mejor calidad de vida y mayor sobrevida. Métodos: se realizó un estudio retrospectivo en pacientes pediátricos diagnosticados en la Fundación Valle del Lili en un periodo de seis años. Resultados: se registraron 10 casos de la enfermedad. No se observaron diferencias por sexo. La edad media de presentación fue de 33 meses. En el diagnóstico por inmuno-histoquímica se identificó histiocitosis de células de Langerhans con compromiso multisistemico -multifocal en cinco casos, uno con compromiso unisistémico - unifocal y otro unisistémica - multifocal y granuloma eosinofílico en los tres restantes. Cinco pacientes presentaron compromiso de órgano de riesgo y uno de ellos murió en el periodo de observación. Conclusión: la histiocitosis de células de Langerhans es una enfermedad de compromiso sistémico muy poco frecuente en pediatría, con diversas formas de presentación clínica, lo que la hace una entidad de difícil diagnóstico y manejo. La inmunohistoquímica es la mejor forma de diagnóstico en esta entidad.

Introduction: Langerhans cell histiocytosis is a rare disease with different clinical and pathological presentation, is clinically divided into three groups: unifocal, multifocal unisystem, and multifocal multisystem Langerhans cell histiocytosis is a consequence of proliferation, accumulation and infiltration of cells that are part of the mononuclear phagocyte system in different organs. The goal with the description of this cases series is to highlight the importance and awareness to a timely diagnosis and management of this entity, for a better quality of life and longer survival. Methods: Retrospective study in pediatric patients diagnosed in the Valle del Lili Foundation over a period of six years. Results: In our series of cases there was no gender difference and the mean age at presentation was 33 months. In the diagnosis by immunohistochemistry identified Langerhans Cell Histiocytosis, the cases were classified as multisystemic -multifocal in 5 patients, unisystemic in 1 patients - unifocal unisystemic in 1 patients -multifocal eosinophilic granuloma in 3 patients. Of the 10 patients 5 had risk organ involvement and 1 died in the observation period. Discussion: la histiocitosis de células de Langerhans es una enfermedad de compromiso sistémico muy poco frecuente en pediatría, de diversas formas de presentación clínica, lo que la hace una entidad de difícil diagnóstico y manejo. La inmunohistoquimica es la mejor forma de diagnóstico en esta entidad.