Sarcoma de Ewing mesencefálico: reporte de caso / Mesencephalic Ewing sarcoma: Case report

El sarcoma de Ewing es una neoplasia de origen más frecuentemente óseo; otras localizaciones son excepcionales. En el caso de las presentaciones primarias intracraneales, resulta imprescindible descartar que se trate de un secundarismo así como también de otros tumores neuroectodérmicos que puedan requerir distintos abordajes diagnósticos y terapéuticos. Se presenta a una paciente de 14 años que consultó por ptosis palpebral de ojo izquierdo asociado a diplopía de 2 meses de evolución; los estudios por imágenes mostraron una lesión tumoral extraaxial situada a nivel de la cisterna interpeduncular. Se realizó la exéresis completa, con diagnóstico anatomopatológico de sarcoma de Ewing de ubicación mesencefálica

Ewing's sarcoma is a malignant neoplasm mainly occurring in the bone, with other locations being exceptional. In the case of primary intracranial presentations, it is essential to rule out metastatic lesions as well as other neuroectodermal tumors that may require different diagnostic and therapeutic approaches. We present a 14-year-old patient who consulted for upper eyelid ptosis of left eye associated with a 2-month history of diplopia, with imaging evidence of extra-axial tumor lesion, located at the level of the interpeduncular cistern. Complete excision was performed, with a pathological diagnosis of Ewing's sarcoma of midbrain location.

Delays in the health care system for children, adolescents, and young adults with bone tumors in Brazil / Atrasos no sistema de saúde para crianças, adolescentes e adultos jovens com tumores ósseos no Brasil

ABSTRACT Objective: To identify delays in the health care system experienced by children and adolescents and young adults (AYA; aged 0-29 years) with osteosarcoma and Ewing sarcoma using information from the Brazilian hospital-based cancer registries. Methods: Patient data were extracted from 161 Brazilian hospital-based cancer registries between 2007 and 2011. Hospital, diagnosis, and treatment delays were analyzed in patients without a previous histopathological diagnosis. Referral, hospital, and health care delays were calculated for patients with a previous histopathological diagnosis. The time interval was measured in days. Results: There was no difference between genders in overall delays. All delays increased at older ages. Patients without a previous histopathological diagnosis had the longest hospital delay when compared to patients with a previous histopathological diagnosis before first contact with the cancer center. Patients with Ewing sarcoma had longer referral and health care delays than those with osteosarcoma who had a previous histopathological diagnosis before first contact with the cancer center. The North and Northeast regions had the longest diagnosis delay, while the Northeast and Southeast regions had the longest treatment delay. Conclusion: Health care delay among patients with a previous diagnosis was longer, and was probably associated with the time taken for to referral to cancer centers. Patients without a previous histopathological diagnosis had longer hospital delays, which could be associated with possible difficulties regarding demand and high-cost procedures. Despite limitations, this study helps provide initial knowledge about the healthcare pathway delays for patients with bone cancer inside several Brazilian hospitals.

RESUMO Objetivo: Identificar atrasos no sistema de saúde em crianças e adolescentes e adultos jovens (AAJ; até 29 anos) com osteossarcoma e sarcoma de Ewing com informações dos registros de câncer de base hospitalar do Brasil. Métodos: Os dados dos pacientes foram extraídos de 161 registros de câncer de base hospitalar brasileiros entre 2007 e 2011. Os atrasos no hospital, no diagnóstico e no tratamento foram analisados em pacientes sem um diagnóstico histopatológico anterior. Os atrasos no encaminhamento, no hospital e no sistema de saúde foram calculados para pacientes com diagnóstico histopatológico anterior. O intervalo de tempo foi medido em dias. Resultados: Não houve diferença entre os sexos nos atrasos em geral. Todos os atrasos aumentaram na faixa etária mais velha. Os pacientes sem um diagnóstico histopatológico anterior apresentaram o atraso hospitalar mais longo em comparação com os pacientes com diagnóstico histopatológico anterior antes do primeiro contato com o centro de câncer. Os pacientes com sarcoma de Ewing apresentaram atrasos no encaminhamento e no sistema de saúde mais longos do que os com osteossarcoma, que apresentaram diagnóstico histopatológico anterior antes do primeiro contato com o centro oncológico. As regiões Norte e Nordeste apresentaram o atraso mais longo no diagnóstico, ao passo que as regiões Nordeste e Sul apresentaram o atraso mais longo no tratamento. Conclusão: O atraso no sistema de saúde entre os pacientes com diagnóstico anterior foi maior e provavelmente associado ao tempo de encaminhamento para os centros oncológicos. Os pacientes sem um diagnóstico histopatológico anterior apresentaram atrasos mais longos no hospital, o que pode ser associado a possíveis dificuldades com relação à demanda e aos procedimentos de alto custo. Apesar das limitações, nosso estudo ajuda a fornecer um conhecimento inicial sobre os atrasos no sistema de saúde para tratamento de pacientes com câncer em vários hospitais brasileiros.

Sarcoma de Ewing extraóseo en espacio epidural / Extraosseous Ewing's sarcoma in spinal epidural space

El sarcoma extraóseo de Ewing pertenece a la familia de tumores neuroectodérmicos que derivan de la cresta neural, característico por su agresividad. Varias localizaciones se han descrito, sin embargo, la presentación epidural es rara. El pronóstico ha mejorado por nuevos esquemas oncológicos y están en estudio otras dianas terapéuticas.

Extraosseous Ewing's sarcoma belongs to the family of neuroectodermal tumors that derive from the neural crest, characteristic of its aggressiveness. Several locations have been described, however,epidural presentation is rare. Prognosis has been improved by new oncological regimens and other therapeutic targets are being studied.

Ewing’s Sarcoma of Zygomatic Bone.

Ewing’s sarcoma is an uncommon malignancy usually arising from the skeletal system particularly pelvic bones and long bones of lower extremities and mostly affecting children and young adults. Its occurrence in the maxillofacial region with soft tissue involvement is struck with rarity. It carries a poor prognosis due to its uncontrolled potential for metastatic spread; therefore an early and integrated treatment approach must be adopted to improve patient’s long term survival.

Sarcoma de Ewing costal / Costal Ewing Sarcoma

The Sarcomas Ewing/PNET is highly aggressive and both tumors present/display he himself phantom of genetic anomalies reason for which the term of “Tumors of the family of sarcoma of Ewing is used (TFSE)” that includes to a group of tumors with a phantom of neuroectodermic differentiation. Case of feminine adolescent of eleven years, that referred sharp pain, in hemitorax appears left, in Rx of the thorax heterogenous dense image of diffuse edges projected on third basal means in left pulmonary field received antibiotics, remained asymptomatic up to eight months later when chest pain reappeared, made Rx of the thorax where demonstrate at level of the eighth costal arc bony erosion, in addition to the image previously described to greater size. Normal physical examinations. normal examinations of laboratory, computerized axial Tomography of the chest demonstrate bony erosion, and commitment of the local pleura biopsy of the injury reported: “Malignant Tumor of round cells, extensive necrosis”. Bony scintygraphy indicated osteoblastic activity altered in D8, suggestive of secondary bony infiltration. Made resection of tumor like injury in chest wall with reconstruction, positioning of prosthesis and central catheter biopsy of bony Marrow: refusal. The morphologic and inmunohistochemical findings with positivity for compatible FLy and CD99 with tumor of the family of sarcoma of Ewing/primtive neuroectodermic tumor. At the moment in treatment programmed with standard chemotherapy every 21 days X-ray in week 12.

Los Sarcomas Ewing/PNET son altamente agresivos y ambos tumores presentan el mismo espectro de anomalías genéticas razón por la que se usa el término de “Tumores de la familia del sarcoma de Ewing (TFSE)” que abarca a un grupo de tumores con un espectro de diferenciación neuroectodérmica. Se presenta caso de adolescente femenina de once años, quien refirió dolor punzante, en hemitorax izquierdo, en Rx del tórax imagen densa heterogénea de bordes difusos proyectada sobre tercio medio basal en campo pulmonar izquierdo. Recibió antibióticos, permaneció asintomática hasta ocho meses después cuando reapareció dolor torácico, y en Rx del tórax se evidencio a nivel del octavo arco costal erosión ósea, además de la imagen anteriormente descrita de mayor tamaño. Examen físico y de laboratorios fueron normales, en Tomografía axial computarizada del tórax se evidencio erosión ósea, y compromiso de la pleura local. Biopsia de la lesión reportó: “Tumor maligno de células redondas, extensa necrosis”. Gammagrama Óseo señaló actividad osteoblástica alterada en D8 sugestivo de infiltración ósea secundaria. Se realizó resección de lesión tumoral, reconstrucción, colocación de prótesis, catéter central biopsia de Médula ósea: negativa. Los hallazgos morfológicos e inmunohistoquímicos con positividad para FLy y CD99 compatible con tumor de la familia del sarcoma de Ewing/tumor neuroectodérmico primitivo. Actualmente en tratamiento programado con quimioterapia estándar cada 21 días Radioterapia en la semana 12.

Retroperitoneal Extraskeletal Ewing's Sarcoma / 대한소화기학회지

No abstract available.

Cytokeratin-positive primitive neuroectodermal tumor of the prostate: Case report and review of literature.

Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) of the prostate is extremely rare. Here, we report a case of ES/PNET of prostate in a 24-year-old man presenting with dysuria and pelvic discomfort. Computed tomography scan revealed a heterogeneous mass involving the prostate without evidence of distant metastases. Histologically, the tumor was composed of small round blue cells strongly and diffusely positive for CD99 and epithelial markers. Fluorescence in situ hybridization confirmed rearrangement of the Ewing's sarcoma region on chromosome 22.

Metástase meníngea em adulto jovem com sarcoma de Ewing da tíbia direita / Meningeal metastasis in young adult with Ewing´s sarcoma of the right tibia

Introdução: O sarcoma de Ewing representa 10% dos tumores ósseos, com predomínio no sexo masculino. A maior incidência é dos 5 aos 14 anos. Acomete mais as extremidades e em 25% dos casos há metástases ao diagnóstico. O acometimento do sistema nervoso central ocorre em 3% dos pacientes. A infiltração das leptomeninges é rara e ocorre predominantemente por contiguidade de uma lesão óssea subjacente. Relato do caso: Mulher de 27 anos com lesão em tíbia direita de 17 cm. A biópsia diagnosticou sarcoma de Ewing. Estadiamento sistêmico foi negativo e planejada quimioterapia neoadjuvante com esquema VAC-IE para preservação do membro. Após o primeiro ciclo de VAC teve neutropenia precoce, infecção de sítio tumoral, sepse e síndrome compartimental do membro. Submetida a amputação suprapatelar. Após 30 dias apresentou paralisia do VII, VI e III pares cranianos à esquerda e VII e III à direita, tomografia computadorizada do crânio foi normal e o líquor confirmou infiltração meníngea. A paciente evoluiu a óbito três dias após o diagnóstico de metástase meníngea. Discussão: A literatura é escassa em informações sobre a frequência do envolvimento meníngeo no sarcoma de Ewing. A forma peculiar do acometimento neste caso, sem metástase óssea que invadisse o sistema nervoso por contiguidade, faz-nos concluir que tal disseminação ocorreu pela via hematogênica. A paciente apresentava fatores de mau prognóstico (tumor > 100ml, idade > 26 anos, intervalo diagnóstico-metástases < 2 anos). O acometimento meníngeo contribuiu para o desfecho desfavorável, pois é um local de difícil controle da doença, considerado um santuário.

Ewing's Sarcoma of the Lesser Sac Masquerading as a Pancreatic Tumor

Extraosseous Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) is an uncommon, aggressive, and malignant tumor with a poor patient outcome. Its occurrence in the lesser sac is a rare event and to the best of our knowledge, has not been previously described. The present case was clinically and radiologically misdiagnosed as a pancreatic tumor/gastrointestinal stromal tumor. Histopathology revealed a tumor with "small round cells" that were positive for CD99, confirming the diagnosis of ES/PNET. This report highlights the importance of considering Ewing's sarcoma in the differential diagnosis of intraabdominal, extraintestinal masses.

Cytological Diagnosis of Ewing Sarcoma – Clavicle.

Ewing sarcoma is a rare malignant round cell tumor of the bone. It is the second most common primary malignant tumor of bone found in children. It commonly affects long bones, pelvis and ribs. An 11 year old boy presented with painful swelling at the medial end of left clavicle. X-ray revealed a diaphyseal lesion of the medial end of the left clavicle with destruction of bone and mottled appearance. FNAC was done and reported as Malignant round cell tumor suggestive of Ewing sarcoma. Histopathologically the diagnosis of Ewing sarcoma was confirmed with special stains. Ewing sarcoma affecting clavicle is uncommon. Clavicle can be often resected with no need of reconstruction in young children.

De la patología estructural a la patología molecular: un modelo en el sarcoma de Ewing / From structural pathology to molecular pathology. A model of Ewing sarcoma

La existencia de un grupo distintivo de neoplasias de células redondas de hueso y partes blandas altamente malignas fue reconocida desde el siglo pasado. Este grupo de tumores de células redondas y pequeñas comprenden un conjunto heterogéneo de neoplasias pobremente diferenciadas formadas por células pequeñas, redondas u ovales con alto índice nuclear-citoplasmático, núcleos redondos con cromatina dispersa o agrupada y nucléolo poco evidente. En el año 1921, James Ewing, profesor de Patología de la Universidad de Cornell, USA, describió estas características histológicas en un tumor que denominó endotelioma difuso de hueso. Charles Oberling, en Paris, en el año 1928, denominó la neoplasia como Sarcoma de Ewing. De manera resumida podemos plantear la evolución de las técnicas diagnósticas aplicadas en el estudio de la siguiente forma: 1) Aplicacion de técnicas convencionales histológicas: H&E. 2) Histoquímica convencional: PAS, Carmin de Best. 3) Microscopía Electrónica. 4) Inmunohistoquímica: marcadores mesenquimales, neurales, epiteliales y otros. 5) Cultivos celulares. 6) Xenotrasplante de tumores. 7) Estudios citogenéticos convencionales: traslocaciones cromosómicas principales. 8) FISH. 9) Biología molecular: reordenamiento genético y tipos de genes de fusión. Se presenta una visión global de los distintos aspectos de la morfología, ultra estructura inmunohistoquímica, genética convencional y molecular asi como nuevas aproximaciones a la terapéutica de este tumor óseo.

Congenital extraskeletal Ewing's sarcoma of chest wall - A rare case report.

Congenital extraskeletal Ewing's sarcoma or peripheral primitive neuroectodermal tumor is an extremely uncommon and invariably fatal tumor. We report a case of extraskeletal congenital Ewing's sarcoma in a female fetus delivered at 34 weeks of gestation who died immediately after birth. In English literature, majority of cases of Ewing's sarcoma in neonates reported were skeletal. To the best of our knowledge, very few cases of extra-skeletal Ewing's sarcoma in neonates are reported in the literature.

Salvataje de miembro superior en pacientes pediátrico con sarcoma de Ewing: a propósito de un caso / Upper limb salvage in pediatric patients with Ewing sarcoma: report of a case

El sarcoma de Ewing es un tumor maligno perteneciente al grupo de tumores neuroectodérmicos primitivos. Se conoce poco acerca de los factores etiológicos y generalmente afecta la diáfisis de hueso largo y la pelvis. Rara vez puede localizarse extraesqueléticamente. La tendencia es a presentarse en gente joven durante la fase de mayor crecimiento. Representa el 1 por ciento de los tumores en la infancia y es el segundo tumor maligno primario del hueso en la niñez y adolescencia, con un pico de edad entre 5 y 13 años. En el presente se reporta el caso de un paciente masculino de 10 años de edad, con diagnóstico de Sarcoma de Ewing Primario en Húmero Izquierdo Estadio III. Fue tratado con esquema de Quimioterapia y Radioterapia; en vista de su buena evolución se ofreció Cirugía Reconstructiva como medida de salvataje del miembro superior. Se realizó resección del húmero con márgenes quirúrgicos amplios y se colocó aloinjerto óseo de tibia, estabilizándose con material de osteosíntesis proximal y distalmente. Como resultado se observó remodelación ósea y osteointegración completa del injerto, así como rangos de movilidad aceptables en el primer año de evolución. Los procedimientos quirúrgicos para la reconstrucción de los miembros, después de la extirpación del Sarcoma de Ewing Primario, constituyen una alternativa en un intento por evitar la amputación.

The Sarcoma of Ewing is a malignant tumor pertaining to the gruop of primitive neuroectodermal tumors. Little is known about the etiologic factors and it generally affects the diaphysis of long bones and pelvis. Rarely it can be located extraskeletally. The tendency is to appear in young people during the phase of greater growth. It represents 1 percent of the tumors in the childhood and is the second primary malignant tumor of the bone in the childhood and adolescence, with a tip of age between 5 and 13 years. In the present work the case of a masculine patient of 10 years of age is resported, with diagnosis of Sarcoma of Primary Ewing in Left Chimney Stage III. It was dealed with schemes Chemotherapy and X-ray; in view of its good evolution Reconstructive Surgery was offered like measurement of salvataje of the member superior. Resection of the chimmey with ample surgical margins was realised and aloinjerto bony of tibia was placed distate, becoming stabilized with material of proximal osteosynthesisand as result were observed bony remodeling and complete osseointegration of the graft, as well as acceptable ranks of mobility in the first yeras of evolution. The surgical procedures for the reconstruction of the members, after the extirpation of the Sarcoma of Primary Ewing, constitute an alternative in an attempt to avoid the amputation.

Sarcoma de Ewing extraósseo / Extraosseous Ewings sarcoma

Introdução: O sarcoma de Ewing é um tipo de tumor que ocorre mais frequentemente nos ossos longos, podendo também estar presente na pelve, coluna e costelas. Admite-se que seja causado por uma anormalidade cromossômica, mais comumente entre os cromossomas 11 e 22. Desenvolve-se a partir de um tipo de célula nervosa primitiva, podendo também ocorrer nas partes moles. É neoplasia óssea de comportamento biológico bastante agressivo, que acomete principalmente indivíduos abaixo dos 30 anos de idade e predomina discretamente em indivíduos do sexo masculino. A causa é desconhecida e não parece ser hereditária. São tumores extremamente raros em negros e asiáticos e o relato na população indígena é desconhecido. Relato do caso: O material coletado na biópsia foi enviado para exame imunoistoquímico, tendo sido utilizados dez anticorpos: desmina, mioglobina, actina, CD99, CD45, citoqueratina AE1/AE3, vimentina, sinaptolisina Ab-1, enolase neuroespecífica e proteína p53. O diagnóstico anatomopatológico foi de sarcoma indiferenciado de células pequenas com expressão difusa de CD99 e enolase neuroespecífica. O perfil imunoistoquímico foi consistente com o diagnóstico de sarcoma de Ewing/Tumor Neuroectodérmico Primitivo Periférico. Realizou-se a extirpação do tumor e o paciente encontra-se em tratamento de quimioterapia. Discussão: São tumores localmente agressivos com prognóstico reservado, geralmente com resultado terapêutico pobre.

Introduction: Ewing's sarcoma is a type of tumor which occurs frequently in long bones and it is also present in pelvis, spinal cord and ribs. It is thought to be caused by a chromosomal abnormality commonly between chromosomes 11 and 22. It develops from a type of primitive nerve cell and it may also occur in soft tissues. It is a bone neoplasm which presents a very aggressive biologic profile; it affects mainly subjects younger than 30 years old and is slightly predominant in males. The cause is unknown and it does not seem to be hereditary. These tumors are extremely rare in blacks and Asians and the report in indigenous population is unknown. Case report: The material collected at biopsy was sent to immunohistochemical examination and we used ten antibodies: desmin, myoglobin, actin, CD99, CD45, cytokeratin AE1/AE3, vimentin, sinaptolisina Ab-1, neuron specific enolase and protein p53. The anatomopathological diagnosis indicated undifferentiated sarcoma of small cells with diffuse expression of CD99 and neuron-specific enolase. The immunohistochemical profile was consistent with the diagnosis of Ewing's sarcoma/Peripheral Primitive Neuroectodermal Tumor. The tumor was removed and the patient was in chemotherapy treatment. Discussion: These tumors are locally aggressive with a reserved prognosis, usually with poor therapeutic outcome.

Sarcoma de Ewing extraesquelético que semeja abdomen agudo / Extra-skeletal Ewing's sarcoma resembling acute abdomen: case report

Introducción: El sarcoma de Ewing extraóseo es un tumor raro de origen neuroectodérmico que se ha presentado principalmente en las partes blandas de las extremidades y del tórax; histológicamente es similar al sarcoma de Ewing en el tejido óseo. Caso clínico: Paciente con abdomen agudo y leucocitosis, en quien por imagen (ultrasonido y tomografía axial computarizada) se diagnosticó enfermedad diverticular complicada del colon, por lo que fue intervenido quirúrgicamente, encontrando lesión localizada en el espacio de Retzius con extensión a la cavidad abdominal de 20 x 15 x 15 cm. El tratamiento consistió en extirpación del tumor, separándolo de las vísceras adyacentes y el paciente fue tratado con quimioterapia: epirrubicina, ciclofosfamida y vincristina por seis ciclos; la tomografía abdominal de control mostró actividad tumoral en el retroperitoneo, adyacente al colon ascendente y ciego, por lo que se requirió nuevo tratamiento resectivo. Conclusiones: En la revisión de la literatura no hay informes previos de sarcoma de Ewing extraóseo cuya presentación sea abdomen agudo. Por la rareza de esta lesión, en la literatura solo hay registro de casos o algunas series de casos, por lo que no fue posible llevar a cabo comparaciones; la extirpación de la lesión es el pilar del tratamiento. No se define el papel de la quimioterapia preoperatoria. La biopsia percutánea guiada por algún método de imagen es de utilidad para otorgar al paciente un tratamiento óptimo que le permita un mejor pronóstico.

BACKGROUND: Extraosseous Ewing's sarcoma is a rare tumor of neuroectodermal origin. It presents mainly in the soft tissue of the extremities and thorax. Histologically, it is similar to Ewing's sarcoma of the bone. CLINICAL CASE: We present the case of a male who arrived at the emergency room with acute abdomen, leucocytosis and imaging techniques (abdominal ultrasound and computed tomography) suggestive of complicated diverticular disease. He was treated with emergency surgery. Intraoperative findings were an unsuspected tumor (20 x 15 x 15 cm). Treatment consisted of extirpation of the tumor, separating it from the adjacent viscera and followed by chemotherapy based on epirubicin, cyclophosphamide and vincristine for six cycles. Because the control abdominal CT demonstrated tumor activity in the retroperitoneum adjacent to the ascending colon and cecum, further resection was decided upon. CONCLUSIONS: In a review of the literature, no previous reports of extraosseous Ewing's sarcoma were found presenting as acute abdomen. Due to the rarity of this tumor, only case reports or series have been found in the literature without randomized or comparative studies. Surgery was the cornerstone of treatment, without reports of preoperative chemotherapy. If the patient's condition permits, percutaneous needle biopsy is mandatory to obtain optimum treatment as well as to improve prognosis.

Ewing's sarcoma of the mandible in a young child

Ewing's sarcoma (ES) is a malignancy primarily affecting bone tissue that is commonly diagnosed in adolescents and young adults. Its occurrence in the head and neck region is unusual and generally involves the mandible and maxilla. An extensive review of the literature shows only few cases of the oral ES in patients under the age of 5. This paper reports a rare case of ES of the mandible in a 4-year-old girl, which had been previously misdiagnosed and treated as a dental abscess. In the clinical examination, a hard immobile expansive mass of 5 cm in diameter was observed on the left side of the mandible. Radiographic examination revealed a radiolucent lesion with ill-defined borders and wide vestibular bone plate destruction. Microscopically, the tumor was composed by monotonous small round cells that exhibited immunoreactivity for CD99, vimentin and pancytokeratin. The patient was subjected to multiagent chemotherapy with ifosfamide, carboplatin, etoposide, vincristine, cyclophosfamide and doxorrubycin (VAC/ICE regimen). However, after the first chemotherapeutic cycle, the patient died due to disseminated infection. This case elucidates the importance of professional knowledge of the relevant aspects of malignant lesions such as ES.

O sarcoma de Ewing é um tumor maligno primário do osso, comumente diagnosticado em adolescentes e adultos jovens. Sua ocorrência na região de cabeça e pescoço não é usual, e geralmente ocorre em maxila ou mandíbula. Após revisão extensiva da literatura, poucos casos foram identificados acometendo pacientes com menos de 5 anos de idade. Nós relatamos um caso raro de SE em uma criança de 4 anos de idade que foi previamente diagnosticada e tratada como abscesso dentoalveolar. Ao exame clínico, uma massa expansiva endurecida e imóvel de 5 cm de diâmetro foi observada no lado esquerdo da mandíbula. O exame radiográfico mostrou lesão radiolúcida, com bordas mal definidas e ampla destruição da tábua óssea vestibular. Microscopicamente, o tumor era composto por células pequenas e arredondadas que exibiam imunorreatividade para CD99, vimentina e pancitoqueratina. O paciente foi submetido à quimioterapia com ifosfamida, carboplatina, e etoposide além de vincristina, ciclofosfamida e doxorrubicina (regime VAC/IE). Entretanto, após o primeiro ciclo da quimioterapia, o paciente foi a óbito por infecção disseminada. Este caso salienta a importância do conhecimento profissional no diagnóstico de tumores malígnas tais como o SE.