Spinal tumors in children / Tumores de coluna em crianças

Summary Introduction: Spinal tumors are rare in the pediatric population, presenting many specific peculiarities when compared to adults. We have performed a broad narrative review to describe the most common spinal tumors in children, discussing their main characteristics and management options. Method: The authors have performed an extensive review of the peer-reviewed literature addressing the aforementioned objectives. Results: Multimodality radiological studies (plain films, 3D computed tomography scan and magnetic resonance imaging) are necessary for proper evaluation and differential diagnosis of spinal tumors in children. In selected cases nuclear medicine imaging is used to improve the chances of a more accurate diagnosis. As a general rule, a fine needle biopsy is recommended after radiological evaluation to confirm the tumor's histology. Primary bone tumors can be divided into benign bone tumors, mostly represented by vertebral hemangiomas, osteoid osteomas, osteoblastomas, aneurismal bone cysts, and eosinophilic granulomas, and malign or aggressive tumors, such as Ewing's or osteogenic sarcomas. Secondary bone tumors (spinal metastases) comprise different tumor histologies, and treatment is mainly based on tumor's radiosensitivity. The characteristics and treatment options of the main spinal tumors are discussed in details. Conclusion: Spinal tumors in children are rare lesions that demand a thorough understanding of their main characteristics for their proper management. Understanding the nuances of spinal tumors in children is of paramount importance for improving outcomes and chances of cure.

Resumo Introdução: Os tumores de coluna em crianças são raros, apresentando peculiaridades únicas quando comparados com os da população adulta. Método: Dada a escassez de trabalhos que avaliem o tema, realizou-se extensa revisão de literatura objetivando descrever os tumores de coluna que acometem a população pediátrica, discutindo características e opções de manejo. Resultados: A utilização de exames radiológicos combinados (radiografias, tomografia computadorizada com reconstrução em 3D e ressonância magnética) é necessária para avaliação adequada e diagnóstico diferencial dessas lesões. Em casos selecionados, exames de medicina nuclear aumentam as chances do diagnóstico preciso. Como regra geral, biópsia por agulha é recomendada para confirmação da histologia tumoral e tratamento subsequente. As lesões primárias de coluna podem ser benignas, representadas principalmente pelos hemangiomas, osteomas osteoides, osteoblastomas, cistos ósseos aneurismáticos e granulomas eosinofílicos, enquanto as lesões malignas são geralmente representadas por tumores agressivos, como o sarcoma de Ewing ou os sarcomas osteogênicos. Metástases de coluna podem ter diferentes etiologias, sendo o tratamento dependente principalmente da radiossensibilidade do tumor de origem. As opções de tratamento dessas lesões são descritas em detalhes. Conclusão: Tumores de coluna em crianças são raros e o seu manejo requer um conhecimento amplo e variado das diferentes possibilidades diagnósticas. Conhecer os nuances envolvidos no tratamento dessas lesões e os sintomas iniciais é fundamental para melhorar o prognóstico e as chances de cura.

Mobilization and collection of CD34+ cells for autologous transplantation of peripheral blood hematopoietic progenitor cells in children: analysis of two different granulocyte-colony stimulating factor doses

The use of peripheral hematopoietic progenitor cells (HPCs) is the cell choice in autologous transplantation. The classic dose of granulocyte-colony stimulating factor (G- CSF) for mobilization is a single daily dose of 10 µg/kg of patient body weight. There is a theory that higher doses of granulocyte-colony stimulating factor applied twice daily could increase the number of CD34+ cells collected in fewer leukapheresis procedures. Objective: The aim of this study was to compare a fractionated dose of 15 µg G-CSF/kg of body weight and the conventional dose of granulocyte-colony stimulating factor in respect to the number of leukapheresis procedures required to achieve a minimum collection of 3 × 106 CD34+ cells/kg body weight. Methods: Patients were divided into two groups: Group 10 - patients who received a single daily dose of 10 µg G-CSF/kg body weight and Group 15 - patients who received a fractioned dose of 15 µg G-CSF/kg body weight daily. The leukapheresis procedure was carried out in an automated cell separator. The autologous transplantation was carried out when a minimum number of 3 × 106 CD34+ cells/kg body weight was achieved. Results: Group 10 comprised 39 patients and Group 15 comprised 26 patients. A total of 146 apheresis procedures were performed: 110 (75.3%) for Group 10 and 36 (24.7%) for Group 15. For Group 10, a median of three (range: 1-7) leukapheresis procedures and a mean of 8.89 × 106 CD34+ cells/kg body weight (±9.59) were collected whereas for Group 15 the corresponding values were one (range: 1-3) and 5.29 × 106 cells/kg body weight (±4.95). A statistically significant difference was found in relation to the number of apheresis procedures (p-value <0.0001). Conclusions: To collect a minimum target of 3 × 106 CD34+ cells/kg body weight, the administration of a fractionated dose of 15 µg G-CSF/kg body weight significantly decreased the number of leukapheresis procedures performed.