Pelvic Ewing Sarcoma: The Great Mimicker.

Ewing sarcoma is the most common malignant bone tumor of the pelvis in children and young adults. Even with aggressive treatment, its survival rate is amongst the poorest. Classical presentation may not be the rule. It may simulate clinically, imagiologically and histopathologically other nonmalignant entities. Therefore, its suspicion should not be overlooked. We report two cases of pelvic Ewing sarcoma: the first mimicking eosinophilic granuloma, and the second mimicking osteomyelitis. In the latter, we also report an atypical finding of its natural history: an initial response to antibiotic and anti-inflammatory treatment. In both cases, we highlight the possibility of an inconclusive percutaneous bone biopsy and the importance of immunochemistry and cytogenetics for the definitive diagnosis.

Pelvic Ewing Sarcoma: The Great Mimicker / Sarcoma de Ewing pélvico: o grande imitador

Abstract Ewing sarcoma is the most common malignant bone tumor of the pelvis in children and young adults. Even with aggressive treatment, its survival rate is amongst the poorest. Classical presentation may not be the rule. It may simulate clinically, imagiologically and histopathologically other nonmalignant entities. Therefore, its suspicion should not be overlooked. We report two cases of pelvic Ewing sarcoma: the first mimicking eosinophilic granuloma, and the second mimicking osteomyelitis. In the latter, we also report an atypical finding of its natural history: an initial response to antibiotic and anti-inflammatory treatment. In both cases, we highlight the possibility of an inconclusive percutaneous bone biopsy and the importance of immunochemistry and cytogenetics for the definitive diagnosis.

Resumo O sarcoma de Ewing é o tumor ósseo maligno da pelve mais comum em crianças e adultos jovens. Mesmo com tratamento agressivo, sua taxa de sobrevivência está entre as piores. A apresentação clássica pode não ser a regra. Ele pode simular clinicamente, imaginologicamente e histopatologicamente outras entidades não malignas. Portanto, sua suspeita não deve ser negligenciada. Relatamos dois casos de sarcoma pélvico: o primeiro imitando granuloma eosinofílico e o segundo imitando osteomielite. Neste último, também relatamos um achado atípico de sua história natural: uma resposta inicial ao antibiótico e ao tratamento anti-inflamatório. Em ambos os casos, destacamos a possibilidade de uma biópsia óssea percutânea inconclusiva e a importância da imunoquímica e da citogenética para o diagnóstico definitivo.

Desafíos en el manejo del sarcoma de Ewing en una paciente testigo de Jehová / Challenges in the care of Ewing's sarcoma in a Jehovah's Witness patient

El sarcoma de Ewing es una neoplasia de hueso y tejidos blandos, cuyo manejo se relaciona con toxicidad hematológica. Este aspecto representa un desafío médico y ético en los pacientes testigos de Jehová quienes, por sus creencias religiosas, rechazan la aplicación de hemoderivados, con riesgo de que se descontinúe la quimioterapia o de que se utilicen dosis subóptimas. Se presenta el caso de una mujer colombiana de 34 años, testigo de Jehová, con diagnóstico de sarcoma de Ewing con estadificación clínica IIB (T1N0M0) en las regiones maxilar y mandibular izquierdas, tratada con quimioterapia, quien presentó un valor mínimo de hemoglobina de hasta 4,5 g/dl y tuvo indicación quirúrgica como parte del tratamiento. En estos pacientes, la decisión de practicar una transfusión comprende implicaciones éticas que requieren alternativas terapéuticas y un abordaje multidisciplinario.

Ewing's sarcoma is a bone and soft tissue neoplasm, whose management is related to hematological toxicity. This aspect represents a medical and ethical challenge in Jehovah's Witnesses patients, who, due to their religious beliefs, reject the blood component transfusion, with the risk of discontinuing chemotherapy or using suboptimal doses. We present the case of a 34-year-old Colombian woman, Jehovah's Witness, diagnosed with Ewing's sarcoma with clinical stage IIB (T1N0M0) in the left maxillary and mandibular regions, treated with chemotherapy, who presented a hemoglobin nadir of up to 4.5 g/dL, and surgical indication as part of the treatment. In these patients, the transfusion decision has ethical implications that require therapeutic alternatives and a multidisciplinary approach.

Sarcoma de Ewing extraesquelético: relato de um caso raro e exuberante simulando lipoma / Extraskeletal Ewing's sarcoma: report of a rare and exuberant case simulating lipoma

Sarcoma de Ewing extraesquelético (EES) é tumor raro e agressivo, acomete mais homens entre 10-20 anos e representa 25% dos sarcomas de Ewing. Caso relatado pelo diagnóstico prévio de lipoma de crescimento acelerado, destacando a importância do diagnóstico histopatológico. Masculino, 14 anos, apresentando tumoração de 10x10cm no ombro direito há um ano, com ultrassonografia sugestiva de lipoma. Realizada exérese da lesão, sendo confirmado EES pela imuno-histoquímica. O diagnóstico de EES em jovens é desafiador frente a outras tumorações subcutâneas, sendo a histopatologia imprescindível. A rápida progressão do tumor e os elevados índices metastáticos evidenciam a importância da terapêutica precoce.

Extraskeletal Ewing sarcoma (EES) is a rare tumor that affects men between 10-20 years old and represents 25% of Ewing sarcomas. We report a case due to the previous diagnosis of a fast-growing lipoma to highlight the importance of histopathological diagnosis. A 14-year-old boy presented 10x10 cm tumor in the right shoulder for a year with ultrasonography suggesting lipoma. The lesion was excised and EES was confirmed by immunohistochemical analysis. EES diagnosis in young people is challenging compared to subcutaneous tumors, and histopathology is essential. The rapid progression of the tumor and high metastatic rates highlight the significance of early treatment.

Ewing Sarcoma/Primitive Neuroectodermal Tumor Involving the Duodenum.

Background: Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) is a soft tissue malignancy arising from the neuroectoderm. While the locations of these extraskeletal manifestations are diverse, origin from the small bowel and small bowel mesentery is extremely rare. Intra-abdominal manifestations of ES/PNETs are nonspecific, and patients present with a wide range of symptoms, most frequently vague abdominal pain. Case Report: A 66-year-old female initially presented with vague and nonspecific symptoms of hypotension, anemia, dyspnea, and coffee-ground emesis. Imaging workup with computed tomography and fluorodeoxyglucose positron emission tomography demonstrated a metabolically active large mass involving the duodenum and measuring 10.3 × 8.8 × 12.3 cm. The mass was characterized as an ES/PNET on histopathologic diagnosis. The patient was treated with chemotherapy followed by radical resection and was disease-free at 1 year postpresentation. Conclusion: This case highlights that while ES/PNETs are rare tumors of the abdomen, they should be considered in cases of large soft tissue masses in patients presenting with nonspecific symptoms. To the best of our knowledge, this case is the fourth report in the literature of an ES/PNET involving the duodenum.

A rare case of Ewing sarcoma metastasis to the oral cavity.

Ewing sarcoma in the head and neck is rare, and metastasis from other bones to the mandible accounts for 0.7% of cases. This report presents a case of oral metastasis in a 24-year-old male patient diagnosed with Ewing sarcoma of the femur (p53 gene mutation and EWSR1-ERG fusion). The chief complaint was numbness in the mandible and pain for 1 month and a hardened, ulcerated exophytic lesion in the right retromolar region. Imaging exams revealed an unspecified thinning of the cortical bone of the inferior alveolar canal in the right mandibular ramus, associated with erosion of the alveolar bone. Histopathological analysis confirmed metastasis of Ewing sarcoma. The patient presented an aggressive disease progression and died 1 month after the oral diagnosis. It is important to recognize the signs and symptoms compatible with rare clinical outcomes, leading to an early diagnosis that can improve patients' quality of life and survival.

Actualización en el uso del PET/CT en sarcoma de Ewing, a propósito de un caso

The use of positron emission tomography with computed tomography (PET/CT) for adult cancer patients is widespread, however, its use in pediatric patients is limited by fear of radiation, monetary cost and lack of awareness of its greater sensitivity in the evaluation of some types of tumors. Ewing's sarcoma is one of the primary pediatric malignancies in which PET/CT with 18F-labeled fluorodeoxyglucose (18F-FDG) has demonstrated greater sensitivity in the evaluation of bone metastases compared to scintigraphy, as well as in the evaluation of treatment response. We report a 13 years old female consulting for retrosternal pain. A chest CT scan showed an infiltrating mass originating in the sternum. A biopsy confirmed the presence of an Ewing sarcoma. The tumor was staged with PET/CT which showed multiple bone lesions not visible in previous studies.

Image-guided core needle biopsy for Ewing sarcoma of bone: a 10-year single-institution review.

OBJECTIVE: To evaluate the performance of image-guided core needle biopsy (IGCNB) for the diagnosis of Ewing sarcoma of bone. METHODS: All patients with a confirmed diagnosis of Ewing sarcoma who underwent IGCNB between January 2007 and December 2016 were included in this retrospective study. Analysis included mean age, skeletal distribution, imaging modality used for biopsy guidance, type of anaesthesia, needle type, number of passes, type of tissue sampled, and complications. RESULTS: The study included 139 patients (94 males and 45 females; mean age 18.7 years) who underwent 141 image-guided core needle biopsies as the primary diagnostic test. Of these, 101 were CT-guided, 38 ultrasound-guided, and 2 utilised both CT and ultrasound guidance. A total of 97.9% were diagnostic at first procedure. Of the 3 non-diagnostic cases, 2 underwent a further IGCNB and were positive, while 1 patient required an open surgical procedure. Only 1 patient (0.7%) suffered an immediate complication, and there were no recorded delayed complications. CONCLUSION: IGCNB is a safe procedure providing a positive diagnosis of Ewing sarcoma of bone in a very high percentage of cases. It should be the first-line method for establishing a diagnosis in suspected Ewing sarcoma of bone. KEY POINTS: • Image-guided core needle biopsy is a safe procedure providing a positive diagnosis of Ewing sarcoma of bone in a very high percentage of cases. • Image-guided core needle biopsy should be the first-line method for establishing a definitive diagnosis in Ewing sarcoma and should be performed at a specialist sarcoma referral centre. • When technically feasible, extra-osseous soft tissue alone can be sampled with confidence as there is no difference in diagnostic performance whether bone or an extra-osseous soft tissue component of the tumour is sampled.

Early versus delayed administration of granulocyte-colony stimulating factor following chemotherapy in pediatric patients with Ewing sarcoma.

BACKGROUND: The optimal timing of initiating granulocyte-colony stimulating factor following chemotherapy in pediatric patients has not been clearly defined. This study aimed to compare the administration of granulocyte-colony stimulating factor on day 1 versus day 3 postchemotherapy in pediatric patients with Ewing sarcoma. METHOD: A retrospective study of pediatric patients with Ewing sarcoma who received granulocyte-colony stimulating factor following chemotherapy between January 2016 and September 2018 at a comprehensive cancer center. The institution's chemotherapy protocol for Ewing sarcoma was modified in April 2017 to include granulocyte-colony stimulating factor initiation on day 3 instead of day 1 post-chemotherapy. Febrile neutropenia requiring hospitalization, duration of hospital stay, and chemotherapy delay were compared for patients before and after the protocol change. RESULTS: Over the study period, 250 cycles were evaluated with day 1 granulocyte-colony stimulating factor and 221 cycles with day 3 granulocyte-colony stimulating factor. There were no differences between the day 1 and day 3 groups in the number of cycles associated with Febrile neutropenia requiring hospitalization (34 vs. 19, p = 0.086), and the length of Febrile neutropenia-related hospitalization (mean 4 ± 2.1 vs. 4.6 ± 1.8, p = 0.123). However, delay in chemotherapy due to neutropenia was reported in significantly more cycles in the day 1 group, compared to the day 3 group (37 vs. 16, p = 0.01). CONCLUSIONS: Febrile neutropenia resulting in hospital admission and the length of hospital stay was not different between pediatric patients with Ewing sarcoma who received granulocyte-colony stimulating factor on day 1 or day 3 post-chemotherapy. Chemotherapy delay due to neutropenia was higher in patients who received granulocyte-colony stimulating factor on day 1. Larger studies are required to fully determine the impact of delayed initiation of granulocyte-colony stimulating factor.

Tumores óseos en edad pediátrica / Bone tumor in the pediatric age

RESUMEN Fundamento: los tumores óseos algunas veces son difíciles de diagnosticar, estos se dividen en benignos y malignos, los benignos son lo más frecuente y entre de ellos el osteocondroma es el principal. Los malignos a pesar de su baja frecuencia tienen importancia por su alta mortalidad, que varía entre 80 a 95 %, y las graves secuelas físicas y emocionales que acarrea su tratamiento en los pacientes. Los tipos de tumor óseo maligno más frecuente son el sarcoma de Ewing y el sarcoma osteogénico. Objetivo: profundizar los conocimientos de los tumores óseos en edad pediátrica. Métodos: la búsqueda de la información se realizó en un periodo de cinco meses (primero de agosto de 2017 al 31 de diciembre de 2017) y se emplearon las siguientes palabras claves: bone neoplasms y Childhood, a partir de la información obtenida se realizó una revisión bibliográfica de un total de 246 artículos publicados en las bases de datos PubMed, Hinari, Medline y SciELO y mediante el gestor de búsqueda y administrador de referencias EndNote, de ellos se utilizaron 50 citas seleccionadas para realizar la revisión, 40 de ellas de los últimos cinco años, donde se incluyeron dos libros. Resultados: se abordan formas de presentación clínica de los tumores óseos y los estudios de tipo imagenológicos, de laboratorio e histológicos. Se describen modalidades de tratamiento tanto conservador como quirúrgico. Conclusiones: los tumores óseos benignos en edad pediátrica son más frecuente y en ellos predomina los osteocondroma y entre los malignos el tumor de Ewing y el sarcoma osteogénico.

ABSTRACT Background: bone tumors are sometimes difficult to diagnose, they are divided into benign and malignant, benign tumors are the most frequent and among them the Osteochondroma is the main one. The malignant ones in spite of their low frequency are important for their high mortality, which varies between 80 to 95%, and the serious physical and emotional consequences that their treatment brings to patients. The most common malignant bone tumor types are Ewing's sarcoma and osteogenic sarcoma. Objective: to deepen the knowledge of bone tumors in pediatric age. Methods: the search of the information was made in a period of five months (from August 1st, 2017 to December 31st, 2017) and the following key words were used: bone neoplasms and Childhood, from the information obtained a bibliographical review of a total of 246 articles published in PubMed, Hinari, Medline, and SciELO databases was made through the EndNote search manager and reference manager, of which 50 selected citations were used to perform the review, 40 of them from the last five years, where two books were included. Results: forms of clinical presentation of bone tumors and imaging, laboratory and histological studies are addressed. Both conservative and surgical treatment modalities are described. Conclusions: benign osseous tumors in the pediatric age are more frequent and osteochondroma predominates in them and malignant tumors include Ewing tumor and osteogenic sarcoma.

Ewing sarcoma, analysis of survival at 6 years with multidisciplinary therapy. / Sarcoma de Ewing, análisis de supervivencia a los 6 años con terapia multidisciplinar.

PURPOSE: The purpose of this study is to present our series of Ewing sarcoma cases and the survival data obtained in the medium term, using a multidisciplinary therapy protocol. MATERIAL, METHODS AND RESULTS: Forty-one Ewing sarcomas were diagnosed, treated and followed-up in our hospital between 2004 and 2009 with an average age of 18.29 years. Seventy-eight percent were to Ewing sarcoma of the bone, the femur being the most frequent location. Sixty-eight percent had a localized stage at the time of diagnosis. At the end of follow-up, 40% of the patients did not survive, most died within the first 5 years of follow-up. DISCUSSION: In Spain, Ewing sarcoma is the most common primary malignant bone tumour in childhood, ahead of osteosarcoma. Its survival rate has increased greatly in the last 40 years, improvement attributable mainly to the aggressive use of chemotherapy and to multidisciplinary treatment, but its prognosis remains very poor, especially for those with metastasis at diagnosis, the main adverse prognostic factor. Because of its high mortality, many authors consider it a disseminated disease from the beginning, with non- detectable micrometastasis that condition final survival. CONCLUSIONS: Early diagnosis and multidisciplinary therapy in referral centres are the best strategies currently available to us to provide these patients the maximum possibilities of cure of this disease.

Lower Extremity Weakness in an Adolescent Female - A Rare Presentation of Ewing Sarcoma.

BACKGROUND: Ewing sarcoma, a rare cause of cord compression, is predominantly of osseous origin but can also originate in soft tissues. Soft-tissue manifestations account for <15% of all Ewing sarcoma tumors, and even fewer cases of Ewing sarcoma originating in the epidural space have been documented. CASE REPORT: A 19-year-old female presented to the emergency department for worsening low-back pain during the previous 6 months and numbness and weakness in her legs during the prior 2 weeks. Magnetic resonance imaging revealed an epidural mass at the L4-L5 level. Intravenous steroids were started for a presumed diagnosis of lymphoma. Orthopedic surgery consultants deferred computed tomography-guided biopsy of the mass out of concern for tumor seeding. Compression symptoms worsened to include foot drop and saddle anesthesia, prompting urgent radiation therapy. After the patient showed poor response to appropriate treatment for lymphoma, other malignant and infectious causes were considered. Biopsy was performed on day 3 of the patient's hospital stay, and by day 7, preliminary cytology results revealed Ewing sarcoma. Subsequent laminectomy and tumor resection produced immediate relief of pain, along with a gradual return of strength and sensation. The mass was found to be of soft-tissue origin and was classified as an extraosseous Ewing sarcoma. The patient was referred to a pediatric oncologist to complete the appropriate chemotherapy after diagnosis. CONCLUSION: This case demonstrates how an uncommon manifestation of a rare disease can mimic a classic presentation of cord compression. Our aim is to bring awareness to this disease and to emphasize the importance of timely biopsy of any mass.

Survival outcome among patients with Ewing's sarcoma of bones and joints: a population-based cohort study

ABSTRACT BACKGROUND: The aim here was to elucidate the current survival condition of patients diagnosed with Ewing's sarcoma of the bones and joints and determine independent risk factors associated with the prognosis. DESIGN AND SETTING: Retrospective cohort study based on the Surveillance, Epidemiology and End Results (SEER) database in the United States. METHODS: We identified 397 patients who were diagnosed with Ewing's sarcoma of the bones and joints between January 2004 and December 2013. The multivariate Cox proportional hazards model was used to determine factors associated with the risk of death by adjusting for various factors. RESULTS: The one, two and five-year disease-specific survival rates were 89.08%, 78.08% and 62.47%, respectively. The factors related to death were age (≥ 18 years versus < 18 years; hazard ratio, HR = 1.77; 95% confidence interval, CI: 1.38-2.31); tumor site (extremity versus spine and pelvis; HR = 2.03; 95% CI: 1.31-2.62); tumor size (> 10 cm versus ≤ 10 cm; HR = 1.78; 95% CI: 1.34-2.56); and type of treatment (surgery alone versus radiotherapy with surgery; HR = 0.51; 95% CI: 0.38-0.89; or radiotherapy alone versus radiotherapy with surgery; HR = 1.61; 95% CI: 1.10-2.39; or no treatment versus radiotherapy with surgery; HR = 1.86; 95% CI: 1.23, 2.58). CONCLUSIONS: Patients with Ewing's sarcoma showed poor survival in situations of age ≥ 18 years, tumor size > 10 cm, receiving radiotherapy alone and receiving no treatment. Patients undergoing surgery alone had better survival.

Extraskeletal Ewing Sarcoma: Report of an Extremely Rare Case in Temporal Region.

Extraskeletal Ewing sarcoma (EES) is an uncommon tumor with low prevalence in the head and neck region. Herein, we report a 13-year-old boy with EES in the temporal region, which was managed by surgery and chemotherapy. The histological characteristics and the clinical manifestations of the lesion and our surgical approach will be discussed as well.

A Case of Long-term Survival in a Patient with Primary Primitive Neuroectodermal Tumor of the Lung / 고신대학교의과대학학술지

Primitive neuroectodermal tumor (PNET) arising primarily in the lung is an extremely rare and aggressive malignancy with poor chances of patient survival. We present a case of long-term survival by a 29-year-old woman with PNET diagnosed after a hertological and immunohertochemical examination of a biopsy specimen obtained by performing video-assisted thoracic surgery. The patient underwent a left lower lung lobe lobectomy and 6 cycles of adjuvant chemotherapy. The patient has been free of any symptoms of the recurrence of the disease for 6 years after treatment completion.

Total Claviculectomy as Treatment of Clavicular Ewing's Sarcoma: a Case Report and Literature Review / 中华骨科杂志

Objective To analyze the efficacy of total claviculectomy in the treatment of Ewing's sarcoma and to discuss the impact of clavicular reconstruction on the outcome.Methods The clinical records of a 13-year-old male patient with left clavicular Ewing's sarcoma were reviewed.The subject received 2 cycles (at an interval of 2 weeks) of neoadjuvant chemotherapy comprising cisplatin 120 mg/m2 (1 d),adriomycin 30 mg/m2 (3 d),and ifosfamide 2.0 g/m2 (5 d).Total claviculectomy was carried out without clavicular reconstruction and the patient underwent 9 cycles of subsequent chemotherapy.The appearance and function of the operated limb,radiological examinations of the surgical site,ECT bone scans and pulmonary CT were followed up.The literatures regarding the total and subtotal excision of the clavicle were reviewed to investigate the importance of clavicular reconstruction.Results After 23-months of follow-up,the patient was subjectively free of limb function compromise.Physical examinations indicated drooping of the operated shoulder by 2 cm,whereas the appearance was similar between both shoulders.Functionality of the operated limb was recovered.The motion of the left shoulder:abduction 90°,adduction 40°,anterior flexion 90°,extension 45°,internal rotation 80°,external rotation 60°,and no restriction of limb elevation.Manual muscle strength tests showed V/V muscle strength of the operated limb.American Shoulder and Elbow Surgeons' form (ASES) and Musculoskeletal Tumor Society (MSTS) score were 96 and 30,respectively.Postoperative X-ray films demonstrated mild thoracic scoliosis.The patient did not appear recurrence and metastasis.Conclusion Total claviculectomy is efficacious for treating clavicular Ewing's sarcoma.Clavicular reconstruction may not be imperative for treatment of clavicular malignancy because of the increased technical difficulty and great risk of complications.

Sarcoma de Ewing extraesquelético de rápido crecimiento en paciente de 2 años: Reporte de caso / Fast growing extraskeletal Ewing sarcoma in a 2 year old patient: Case report

El sarcoma de Ewing forma parte de una familia de tumores que se caracterizan por presentar translocaciones que involucran al gen EWS y algún miembro de la familia ETS que posee un dominio de unión al ADN. Se presenta el caso de un paciente de dos años de edad con una masa cervical de crecimiento rápido que por compresión local comprometió estructuras nerviosas manifestándose inicialmente con un retardo en el neurodesarrollo. Se diagnosticó Sarcoma de Ewing/Tumor neuroectodérmico primitivo por biopsia. Este es un tipo de tumor raro con una presentación inusual a nivel cervical; el cual debe tenerse en cuenta al momento de evaluar pacientes con masas cervicales en especial las de crecimiento rápido con el fin de dar un tratamiento preciso y oportuno.

Ewing's sarcoma is part of a family of tumors that is characterized by translocations that involve the EWS gene and a member of the ETS family that has a DNA binding domain. The case of a two-year-old patient who was admitted in our institution because of a rapidly growing cervical mass associated to neurodevelopment setback and functional gradual loss due to nerve compression. Ewing's sarcoma / primitive neuroectodermal tumor was diagnosed by biopsy. This is a rare type of tumor with an unusual presentation in this location; which should be taken into account when assessing a patient with cervical masses, especially those of rapid growth in order to provide an accurate and opportune treatment for improving outcomes.

Incidencia de tumores óseos malignos en niños: estudio de cinco años / Malignant incidence of osseous tumors in children: a five-year study

Fundamento: los tumores óseos malignos en el niño son bastante raros. Comparado con el resto de los tumores infantiles ocupa solo un 3 a 4 %. A pesar de su baja frecuencia tienen importancia por su alta mortalidad, que varía entre 80 a 95 %, y las graves secuelas físicas y emocionales que acarrea su tratamiento en los pacientes. Los tipos de tumor óseo maligno más frecuente a esta edad son el sarcoma de Ewing y el Sarcoma osteogénico. Objetivo: determinar cuáles son los tumores óseas malignos más frecuentes con un estudio de cinco años de los casos ingresados en el Hospital Pediátrico Universitario Eduardo Agramonte Piña de Camagüey en menores de 19 años. Métodos: se realizó un estudio observacional, descriptivo, longitudinal y retrospectivo a través de la revisión del archivo de anatomía patología del Hospital Pediátrico Universitario Eduardo Agramonte Piña de Camagüey. Se estudiaron todos los casos con diagnóstico histopatológico de tumor óseo maligno desde el 1ro de enero 2012 a 31 de diciembre de 2016, con edades inferiores a los 19 años. La fuente de información fue el libro de registro de biopsias del departamento de Anatomía Patológica, los datos obtenidos se compilaron en un formulario elaborado para los mismos. El análisis estadístico se realizó con el paquete estándar profesional S.P.S.S versión 21 2012. Los resultados se presentaron en tablas. Resultados: los tumores óseos malignos de mayor incidencia fueron el sarcoma de Ewing y el Sarcoma osteogénico. El grupo de edad más frecuente de tumores óseos fue entre 10 a 14 años. Conclusiones: el resultado del estudio es comparable con lo reportado en la bibliografía médica donde los tumores óseos malignos, el sarcoma de Ewing y el sarcoma osteogénico son los másfrecuentes.

Background: malignant bone tumors in children are quite rare. When compared to the rest of the childhood tumors it occupies only 3 to 4%. Despite their low frequency, they are important because of their high mortality, ranging from 80 to 95%, and the serious physical and emotional sequelae that their treatment entails in patients. The most frequent types of malignant bone tumor at that age are Ewing's sarcoma and osteogenic sarcoma. Objective: to determine the most frequent malignant bone tumors with a five-year study of the cases admitted to the Eduardo Agramonte Piña University Pediatric Hospital in Camagüey under the age of 19 years. Methods: an observational, descriptive, longitudinal and retrospective study was carried out through a review of the anatomy pathology file of the Eduardo Agramonte Piña University Pediatric Hospital in Camagüey. We studied all cases with histopathological diagnosis of malignant bone tumor from January 1, 2012 to December 31, 2016, with ages below 19 years. The source of information was the biopsy record book of the Department of Pathology. The data obtained were compiled in a form prepared for them. Statistical analysis was performed using the standard professional package S.P.S.S version 21 2012. The results were presented in tables. Results: Ewing’s sarcoma and osteogenic sarcoma were the most frequent malignant tumors. The most frequent age group of bone tumors was between 10 and 14 years. Conclusions: the results of the study are comparable to those reported in the medical literature where malignant bone tumors, Ewing's sarcoma and osteogenic sarcoma are the most common.