Quiste óseo aneurismático en el cuboides de un niño de 13 años. Presentación de un caso clínico / Aneurysmal bone cyst of the cuboid. Case report and review of the literature

Se presenta un caso clínico poco frecuente de un quiste óseo aneurismático localizado en el cuboides de un niño de 13 años. Se llegó al diagnóstico mediante la tríada de síntomas, estudios por imágenes (radiografía, resonancia magnética) y anatomía patológica. El tratamiento consistió en el abordaje y curetaje minuciosos dentro de la lesión, el fresado de alta velocidad, la electrocauterización y el relleno con aloinjerto óseo liofilizado con chips cortico-esponjosos. Pese al diagnóstico tardío, la evolución clínica fue favorable con remisión completa de los síntomas y retorno a las actividades deportivas, sin recidiva local. Nivel de Evidencia: IV

A rare clinical case of an aneurysmal bone cyst located at the level of the cuboid in a 13-year-old boy is presented. The diagnosis was reached through clinical evaluation, imaging studies (radiograph-MRI), and a pathological anatomy analysis. Its treatment consisted of thorough intralesional curettage, high speed burring, electrocautery, and filling with lyophilized bone allograft with cortical/cancellous chips. Despite the late diagnosis, we would like to highlight the favorable clinical evolution of the patient, with ad integrum remission of the symptoms and return to his sport activities, without elements of local recurrence. Level of Evidence: IV

Quistes óseos aneurismáticos. Terapia celular con células mononucleares y seguimiento imagenológico en dos pacientes adolescentes / Aneurysmal bone cysts. Mononuclear cell therapy and imaging follow-up in two adolescent patients

RESUMEN Los quistes óseos aneurismáticos son frecuentes en la edad pediátrica. Para su determinación se cuenta con diversos estudios imagenológicos como la radiografía y la tomografía axial computarizada que pueden colaborar al diagnóstico diferencial con otras lesiones. Existen disímiles opciones terapéuticas, el uso de factores de crecimiento autólogos se ha considerado como alternativa eficaz. Se presentan dos pacientes consultados en el servicio de Ortopedia del Hospital Provincial Pediátrico Universitario «José Luis Miranda¼, de Villa Clara, con diagnóstico clínico e imagenológico de quiste óseo aneurismático que recibieron tratamiento mediante terapia celular con células mononucleares con buena evolución clínica y radiográfica. Esta técnica es aplicable en nuestro medio ya que no requiere de estimables recursos materiales lo que constituye una fortaleza para su implementación. Las radiografías permiten reconocer la evolución posterior al tratamiento.

ABSTRACT Aneurysmal bone cysts are common in children. For its determination, various imaging studies are available, such as radiography and computerized axial tomography, which can collaborate in the differential diagnosis with other lesions. There are dissimilar therapeutic options, the use of autologous growth factors has been considered as an effective alternative. We present two patients seen in the Orthopedics service at "José Luis Miranda" University Pediatric Hospital in Villa Clara, with a clinical and imaging diagnosis of aneurysmal bone cyst who received treatment with mononuclear cell therapy having a good clinical and radiographic evolution. This technique is applicable in our environment since it does not require considerable material resources, which constitutes a strength for its implementation. X-rays allow us to recognize the evolution after treatment.

Uso de denosumab en quiste óseo aneurismático: revisión de la literatura / Use of denosumab in aneurysmatic bone cyst: literature review

INTRODUCCIÓN Los quistes óseos aneurismáticos (QOAs) son tumores benignos, localmente agresivos, y con importante potencial de recidiva, que representan aproximadamente el 1% de todos los tumores óseos. Se describen múltiples tratamientos, como: escisión intralesional, embolización arterial selectiva, inyección de agentes esclerosantes, y radiación. Estos tratamientos tienen una tasa variable de eficacia, ya que la recurrencia puede llegar al 20% y puede estar asociada a comorbidades graves como la pérda funcional de la extremidad. OBJETIVO Realizar una revisión integradora de la literatura sobre el uso de denosumab para el tratamiento de QOAs, describiendo el perfil epidemiológico, la dosis utilizada, y las complicaciones. MÉTODO Se recopilaron artículos publicados en los últimos cinco años en la base de datos PubMed. La información recogida de los casos reportados fue la edad, el sexo, la ubicación del tumor, la realización de cirugía antes y/o después del tratamiento con denosumab, la dosis utilizada, las complicaciones, y la recurrencia. RESULTADOS Se analizaron 7 artículos, 4 reportes de casos y 3 series de casos, escritos en inglés, y publicados de 2014 a 2019. La mayoría de los pacientes eran del sexo femenino, con una edad promedio de 14 años, y el tumor localizado en la columna. CONCLUSIÓN El uso de denosumab en el tratamiento de QOAs ha tenido una buena respuesta, ya que tiene bajas tasas de recurrencia y complicaciones; sin embargo, hacen falta más estudios para definir el protocolo de tratamiento.

INTRODUCTION Aneurysmal Bone Cysts (ABCs) are locally-aggressive benign tumors with relevant potential for recurrence, representing approximately 1% of all bone tumors. Multiple treatments are described for them, such as: intralesional excision, selective arterial embolization, injection of sclerosing agents, and radiation. These treatments have a variable efficacy rate, can reach 20% and may be associated with serious comorbidities such as functional loss of the limb. OBJETIVE To perform an integrative review of the literature on the use of denosumab in the treatment of ABCs, describing the epidemiological profile, the dosage used, and the complications. METHODOLOGY Articles published in the past five years were retrieved from the PubMed database. The information collected from the cases reported was age, gender, tumor location, the performance of surgery before and/or after the denosumab treatment, the dose used, the complications, and recurrence. RESULTS We analyzed 7 articles, 4 case reports and 3 case series, written in English, and published from 2014 to 2019. Most patients were female, with an average age of 14 years, with the tumor located in the spine. CONCLUSION The use of denosumab in the treatment of ABCs yielded good results, with low rates of recurrence and complications. However, further studies are needed to define a treatment protocol.

Estudio radiológico simple de quiste óseo simple y aneurismático: diagnóstico diferencial / Plain radiologic assessment of unicameral and aneurysmal bone cyst: differential diagnosis

OBJETIVO Dar a conocer nuestra experiencia en el diagnóstico diferencial de los quistes óseos simple y aneurismático mediante estudio radiológico simple. MATERIALES Y METODOS Se incluyeron pacientes menores de 20 años con radiografía de quiste óseo simple o aneurismático histológicamente confirmado pertenecientes al Registro Nacional de Tumores Óseos. Las radiografías fueron analizadas por dos radiólogos experimentados. Se compararon las variables demográficas de los pacientes, y las variables clínicas y radiológicas de ambos quistes. RESULTADOS Un total de 97 pacientes cumplieron los criterios de inclusión (65% presentaba quistes óseos simples y 35%, aneurismáticos). No se observaron diferencias en cuanto a la edad, al hueso comprometido, al tamaño de la lesión, a la expansión ósea, ni al adelgazamiento cortical. El género, la forma de presentación, la presencia de interrupción de la cortical, y la localización de la lesión en los ejes longitudinal y transversal del hueso son parámetros que podrían ser útiles en el diagnóstico diferencial de ambos quistes. DISCUSIÓN Los quistes óseos simple y aneurismático son lesiones benignas frecuentes que, de acuerdo con la literatura, serían difíciles de diferenciar únicamente con radiografía simple. La resonancia magnética permite una mejor caracterización anatómica, y aporta sensibilidad y especificidad al diagnóstico. Sin embargo, debe ser precedida por la radiografía simple, y su disponibilidad es limitada. CONCLUSIÓN Aun en centros con disponibilidad de resonancia magnética, la radiografía simple sigue siendo el estudio inicial de elección en el diagnóstico de tumores óseos. Ciertas características demográficas y radiográficas permiten orientar el diagnóstico diferencial inicial entre el quiste óseo simple y el aneurismático

OBJETIVE To describe our experience in the differential diagnosis of unicameral and aneurysmal bone cysts using plain radiography. PATIENCES AND METHODS We included patients under 20 years of age with radiographs of histologically-confirmed unicameral or aneurysmal bone cysts found on the Chilean National Bone-Tumor Registry. The radiographs were evaluated by two experienced radiologists. We compared the demographic variables of the patients, and the clinical and radiological variables of both tumors.. RESULTADOS A total of 97 patients met the inclusion criteria, 65% of whom had simple bone cysts, and 35%, aneurysmal bone cysts. No differences were found regarding age, the bone affected, the size of the lesion, bone expansion, nor cortical thinning. Gender, clinical presentation, cortical interruption, and location of the lesion on the longitudinal and transverse bone axes are parameters that could be used in the differential diagnosis of both cysts. DISCUSSION According to the literature, unicameral and aneurysmal bone cysts are frequent benign lesions that are difficult to differentiate merely through plain radiographs. Magnetic resonance imaging enables a better anatomical characterization and provides sensitivity and specificity to the diagnosis. However, its availability is limited, and it should be preceded by plain radiography. CONCLUSION Plain radiography is still the initial imaging study of choice in patients with clinical suspicion of bone tumor, even in those centers where magnetic resonance imaging is available. Certain demographic and radiological characteristics guide physicians in the differential diagnosis of unicameral and aneurysmal bone cysts.

Quiste óseo aneurismático vertebral agresivo: presentación de un caso y revisión bibliográfica / Aggressive aneurysmal bone cyst of the spine. Case report and literature review

Introducción: El quiste óseo aneurismático es una lesión seudotumoral lítica, expansiva, compuesta por espacios llenos de sangre separados por tabiques. Representa el 15% de los tumores primarios en la columna, y su presentación de comportamiento agresivo es aún más infrecuente. Se han descrito diferentes opciones terapéuticas en función de su estadio y tasa de recurrencia. Presentamos a un paciente con compromiso neurológico secundario a un quiste óseo aneurismático en la columna torácica, de comportamiento agresivo, que requirió resolución quirúrgica. Conclusión: Las opciones de tratamiento del quiste óseo aneurismático se deben adecuar a cada caso en particular, según sus características. Nivel de Evidencia: IV

Introduction: An aneurysmal bone cyst is an expansive, lytic, pseudotumoral lesion that consists of blood-filled spaces separated by septa. It represents 15% of primary spinal tumors. An aggressive presentation is even rarer. Different therapeutic options are described depending on its stage and recurrence rate. We present the case of a patient with neurological involvement due to the aggressive behavior of an aneurysmal bone cyst in the thoracic spine, which required surgical treatment. Conclusion: Treatment options for aneurysmal bone cysts must adapt to each case, depending on its characteristics. Level of Evidence:IV

Uso de denosumab para el quiste óseo aneurismático de columna. Reporte de un caso y revisión bibliográfica / Use of denosumab in an aneurysmal bone cyst of the spine. Case report and literature review

Los tumores vertebrales de columna tienen una frecuencia muy baja. La incidencia de quiste óseo aneurismático es del 1-4% de todos los tumores. Su ubicación predominante es la columna lumbar, en mayor medida, en el arco posterior. Según estudios publicados, esta enfermedad se comporta de forma agresiva, por la compresión radicular que genera debido a su expansión. Si bien hay bibliografía sobre el tratamiento quirúrgico del tumor y su resección en bloque y embolización, no hay experiencias sobre el tratamiento con anticuerpos monoclonales. Existen muy pocos artículos que corroboren un tratamiento para las recidivas o los quistes óseos aneurismáticos inoperables o intralesionales, los cuales dejan la posibilidad abierta a otras técnicas. Presentamos el caso de una mujer de 38 años con lumbocruralgia. En los estudios, se detecta una tumoración, y la biopsia por punción y las imágenes confirman que se trata de un quiste óseo aneurismático. Se planifica el tratamiento con embolización preoperatoria y exéresis intracompartimental mediante cirugía posterior con liberación del saco dural. A los seis meses, el tumor recidiva. Se indica tratamiento con denosumab por dos años, se realizan controles periódicos y se constata la remisión de los síntomas y la mejoría de las imágenes. Nivel de Evidencia: IV

Vertebral tumors of the spine have a very low frequency. The incidence of aneurysmal bone cyst (ABC) ranges between 1% and 4% of all tumors. Its predominant location is the lumbar spine, to a greater extent, in the posterior arch. According to published studies, this condition behaves aggressively, due to the root compression generated by its expansion. While there is literature on the surgical treatment of the tumor and its en bloc resection and embolization, there is no experience on the treatment with monoclonal antibodies. There are very few published articles that corroborate a treatment for recurrences or for inoperable or intralesional aneurysmal bone cysts, which leave the possibility open to other techniques. We present the case of a 38-year-old woman with lumbar pain radiating to the thigh. In studies, a tumor was detected, and the needle biopsy and imaging confirmed that it was an aneurysmal bone cyst. We planned the treatment with preoperative embolization and intracompartmental excision by subsequent surgery with the release of the dural sac. At six months, tumor recurrence was observed. Treatment with denosumab was indicated for two years, periodic controls were carried out and the remission of symptoms and improvement in the images were verified. Level of Evidence: IV

Quiste Óseo Aneurismático en Clavícula: Reporte de un caso / Clavicle Aneurysmal Bone Cyst, Case Report

Introducción:El quiste óseo aneurismático es una neoplasia benigna poco común de aparición en edad temprana. Tiene mayor incidencia en huesos largos y en la columna vertebral. Su etiología es incierta, aunquesuele asociarse a traumatismo, probablemente debido a obstrucción venosa o a la formación de fístulas que se producen tras la contusión. Caso:En este estudio se presenta el caso de un paciente de 15 años sin antecedentes de trauma que presenta un quiste óseo aneurismático en clavícula, localización poco habitual para esta patología. Evolución: Se le brindótratamiento con terapia esclerosante con Polidocanol al 3% por 8 ocasiones con respuesta favorable.No ha requerido cirugía hasta el momento. Conclusión:El tratamientoesclerosante fue exitoso en este informe de casos

Introduction: The aneurysmal bone cyst is a rare benign neoplasm that appears at an early age. It has a higher incidence in long bones and in the spine. Its etiology is uncertain, although it is usually associated with trauma, probably due to venous obstruction or the formation of fistulas that occur after contusion. Case: This study presents the case of a 15-year-old patient with no history of trauma who presents with an aneurysmal bone cyst in the clavicle, an unusual location for this pathology. Evolution: Treatment with sclerosing therapy with 3% Polidocanol was given 8 times with a favorable response. He has not required surgery so far. Conclusion: Sclerosing treatment was successful in this case report

Displasia fibrosa de columna lumbar en una mujer de mediana edad: Presentación de un caso / Fibrous dysplasia of the lumbar spine in a middle-aged woman. Case presentation

La displasia fibrosa es una lesión ósea benigna caracterizada por el desarrollo anormal del tejido fibroso de disposición arremolinada, con trabéculas de hueso inmaduro no laminar. Se distinguen dos formas: monostótica y poliostótica. El compromiso de columna vertebral se asocia, con más frecuencia, a la variedad poliostótica; la forma monostótica es infrecuente. Presentamos a una mujer de 46 años que consultó por lumbocruralgia derecha de dos meses de evolución, con diagnóstico definitivo de displasia fibrosa de columna lumbar. Los estudios por imágenes mostraron una lesión monostótica lítico-quística con tabiques internos localizada en el arco posterior de la quinta vértebra lumbar. Sus características en los estudios por imágenes sugirieron un quiste óseo aneurismático, mientras que la anatomía patológica fue reveladora frente al diagnóstico final de displasia fibrosa. Los síntomas menores y la ausencia de complicaciones llevaron a indicar un tratamiento conservador. Si bien el compromiso de columna lumbar por displasia fibrosa monostótica es infrecuente, debería considerarse entre los diagnósticos diferenciales de una lesión lítica solitaria en dicha localización. No obstante, no se descarta mediante histopatología que pueda tratarse de un caso de coexistencia de displasia fibrosa y quiste óseo aneurismático o que la displasia fibrosa se haya desarrollado sobre un quiste óseo aneurismático. Nivel de Evidencia: IV

Fibrous dysplasia (FD) is a benign skeletal disorder characterized by abnormal development of fibrous tissue in a whorled pattern and containing trabeculae of immature non-lamellar bone. FD has two forms of clinical presentations: monostotic and polyostotic. Spinal involvement is seen mostly in the polyostotic form and is very unusual in the monostotic form. We present a 46-year-old woman that complained of right low back pain with a 2-month evolution. The definitive diagnosis was FD of the lumbar spine. Imaging testing revealed a lytic-cystic monostotic lesion with internal septa located in the posterior arch of the fifth lumbar vertebra, suggestive of Aneurysmal Bone Cyst (ABC). However, the anatomical pathology revealed FD as the final diagnosis. Conservative treatment was undertaken due to minimal symptoms and the absence of complications. Although monostotic FD of lumbar spine is rare, it should be taken into account among the differential diagnoses of a single osteolytic lesion. However, histopathology testing cannot rule out the coexistence of FB and ABC or a setting of FB secondary to an ABC. Level of Evidence: IV

Aneurysmal Patellar Bone Cyst: Case Reportt / Cisto Ósseo Aneurismático de Patela: Relato de Caso

Abstract Patellar tumors are rare. Commonly benign, giant-cell tumors and chondroblastomas are the most frequent types of this tumor. Aneurysmal bone cysts are a less common type, corresponding to less than 1% of the cases. The authors present a case of a 23-year-old male patient who presented left patellar pain and swelling for two years. The radiographic images suggested tumoral causes, and the biopsy was negative for neoplasm. The treatment approach was a complete patellectomy, without complications. The imaging follow-up showed no recurrence.

Resumo Os tumores patelares são uma condição rara. Comumente benignos, o tumor de células gigantes e o condroblastoma são os tipos mais frequentes. O tipo menos comum entre os tumores patelares é o cisto ósseo aneurismático, que corresponde a menos de 1% dos casos. Os autores relatam o caso de um paciente do sexo masculino, de 23 anos, com dor e aumento do volume da patela esquerda havia 2 anos. A radiologia sugeriu causas tumorais, e a biópsia foi negativa para neoplasia. A abordagem terapêutica escolhida foi uma patelectomia total, feita sem intercorrências. O acompanhamento com imagens não mostrou recorrência.

Monostotic craniofacial fibrous dysplasia: report of two cases with interesting histology

Fibrous dysplasia (FD) is a relatively rare osseous disease of unknown etiology, wherein the normal bone is replaced by collagen-rich tissue, comprising of fibroblasts and variably abundant immature woven bone. Clinically, it may involve a single bone or multiple bones. It commonly arises in the jaw bone, skull, rib, and proximal femur. Those arising in the skull and the jaw are together termed "craniofacial fibrous dysplasia." The differential diagnosis at this location includes meningioma and metastatic carcinoma. In this report, we highlight two diagnostically challenging cases presenting with orbital swelling and headache as the main complaints. Our first case was misinterpreted as meningioma on intraoperative squash smear, and paraffin sections revealed characteristic features of FD. The second case highlights the morphological feature of non-specific cystic degeneration occurring in FD. Radiographs in such cases show cystic swelling, which is indicative of a secondary aneurysmal bone cyst.

Caso Clínico: Quiste Óseo Aneurismático de Peroné Distal, Tratamiento con Aloinjerto Estructural / Case Report: Distal Fibula Aneurysmal Bone Cyst, Treatment with Structural Allograft

INTRODUCCIÓN: El quiste óseo aneurismático es una neoplasia benigna que aparece con mayor frecuencia en la segunda década de vida. Clínicamente se presenta como una masa que produce dolor y deformidad de la extremidad afectada; radiológicamente se caracteriza por lesiones líticas con tabicaciones internas y abombamiento de la cortical. Se presenta un caso donde se realizó un aloinjerto estructural para el tratamiento de esta patología. CASO CLÍNICO: Paciente de sexo masculino, de 18 años de edad; con historia de 5 meses de evolución de dolor e impotencia funcional de extremidad inferior derecha; al examen físico se evidenció masa de 15 x 6 cm en tobillo derecho. La radiografía simple demostró una lesión lítica de tercio distal de peroné con adelgazamiento e insuflación de la cortical. El examen histopatológico fue positivo para células gigantes de tipo osteoclasto, cambios simplásticos, estroma miofibroblástico y extravasación eritrocitaria; datos compatibles con quiste óseo aneurismático. EVOLUCIÓN: Se realizó la resección en bloque de la masa tumoral del peroné, para la reconstrucción se utilizó un aloinjerto estructural más estabilización con placa de compresión dinámica y tornillo transindesmal; se realizó además una reconstrucción ligamentaria utilizando la técnica de Watson Jones. El paciente tuvo una evolución favorable, a los 16 meses del procedimiento se observó consolidación completa, además de una función articular conservada; no se evidenció recidiva en los 5 años posteriores de control. CONCLUSIÓN: El quiste óseo aneurismático es una patología benigna que siendo tratada en etapas iniciales, conlleva un mejor pronóstico y requiere de la realización de procedimientos quirúrgicos menos complejos. En pacientes con tumores de gran tamaño no es posible la realización de tratamientos convencionales; siendo la resección en bloque más la colocación de aloinjerto y estabilización ligamentaria, una alternativa terapéutica válida que permita preservar la extremidad.(ua)

BACKGROUND: Aneurysmal bone cyst is a benign neoplasm that presents more frequently in the second decade of life. Clinically It manifests as a mass that causes pain and deformity of the affected limb; radiologically, it is characterized by lytic lesions with internal septations and bulging of the cortex. A case is presented where a structural allograft was performed for the treatment of this pathology. CASE REPORT: 18 year-old male patient, with 5 month history of pain and functional impotence of right lower extremity; physical examination revealed a 15 x 6 cm mass in right ankle. X-ray showed a lytic lesion in the distal third of the fibula, with thinning an insufflation of bone cortex. The histopathological report was positive for giant cells (osteoclast-like cells), symplastic changes, myofibroblastic stroma and erythrocyte extravasation; data compatible with aneurysmal bone cyst. EVOLUTION: An en-bloc resection of the fibular tumor was performed, for the reconstruction a structural allograft plus stabilization with dynamic compression plate and transindesmal screw was used; a ligament reconstruction was also performed using the Watson Jones technique. The patient had a favorable evolution, at 16 months complete consolidation in addition to a preserved joint function was observed; there was no recurrence in the 5 years after control. CONCLUSION: The aneurysmal bone cyst is a benign condition that if treated in initial stages, has a better prognosis and requires less complex surgical procedures. In patients with large tumors, conventional treatment is not possible; en bloc resection plus allograft placement and ligament stabilization, is a valid therapeutic alternative to save the limb.(au)

Aneurysmal Bone Cyst of the Skull Base ­ Case Report

Introduction Aneurysmal bone cysts (ABCs) are pseudotumoral bone lesions of unknown etiology that are also hypervascularized, benign, and locally destructive. They are rare in the base of the skull. The present case report describes a case of aneurysmal bone cyst in the sella turcica. Case Report The present study was developed at the department of neurosurgery of the Hospital Universitário Professor Alberto Antunes of the Universidade Federal de Alagoas (HUPAA-AL, in the Portuguese acronym), Maceió, state of Alagoas, Brazil, and is accompanied by a review of the literature from the PubMed database. A 17-year-old female patient with bitemporal hemianopia and intense left hemicranial headache associated with symptoms from the cranial nerves contained in the cavernous sinus. Neuroimaging evidenced a large lesion in the suprasellar region with calcification foci, sellar erosion, and extension to the cavernous sinus. The patient was submitted to a partial lesion resection and the histopathological analysis showed an aneurysmal bone cyst. Conclusion A rare case of intracranial aneurysmal bone cyst, with the important differential diagnosis from pituitary adenoma.

Quiste óseo aneurismático localizado en el techo acetabular en un varón de 11 años / Aneurysmal bone cyst located on the acetabular roof in an 11-year-old male

Resumen: El quiste óseo aneurismático es una tumoración benigna poco común, de aparición en la infancia generalmente y a nivel de extremidades. El tratamiento más habitual consiste en el curetaje y relleno con injerto. No obstante, localizaciones poco accesibles a la cirugía suponen un reto terapéutico. Se presenta el caso de un paciente de 11 años con cojera y dolor en cadera derecha sin antecedente traumático ni infeccioso. En los estudios de imagen con TAC y RM se evidencia una lesión lítica expansiva que ocupa todo el techo del acetábulo y pala ilíaca derecha, sugestiva de un quiste óseo aneurismático presentando fractura acetabular asociada. Se realizó una biopsia que confirmó el diagnóstico. Se trató mediante embolización guiada por angiografía debido al gran volumen y alto riesgo de fractura, después del curetaje y relleno con aloinjerto evolucionó satisfactoriamente y el paciente se encuentra asintomático al año de la intervención.

Abstract: The aneurysmal bone cyst is a benign rare tumor, which usually develops during childhood and it's more often found in limbs. The most accepted treatment consists in curetagge and filling with graft. However, certain locations may be inaccesible for surgery and represent therapeutical challenges. We present the case of an 11 year-old male patient with limping and right hip pain without any traumatic nor infectious record. In the image studies with CT and MRI a lytic and expansive lession was found in the upper part of the right acetabulum and right iliac wing, all of which suggested an aneurysmal bone cyst with an associated acetabular fracture. A biopsy was performed which confirmed the diagnosis. He was treated with a CT-guided embolization and, due to its size, curetagge and allograft filling afterwards. He was asymptomatic after1 year of follow-up.

Tumores benignos que producen fracturas en niños / Benign tumors that cause fractures in children

Resumen: Introducción: Se define fractura patológica a la que se produce a través de un hueso anormal. Cada año se diagnostican aproximadamente 20,000 neoplasias benignas del sistema musculoesquelético. A menudo, el dolor de la fractura es el primer síntoma de un proceso patológico en el hueso. El sitio, la edad y la apariencia radiográfica crean un diagnóstico diferencial para las fracturas patológicas que sigue siendo amplio. El examen clínico evalúa la condición de la piel, palpar cualquier masa de tejido y determinar si hay signos inflamatorios locales como eritema, calor o edema. La toma de biopsia es muy recomendable para confirmar el diagnóstico de una fractura patológica. Objetivo: Determinar qué tumores óseos benignos y qué lesiones seudotumorales producen fracturas en huesos de niños con mayor frecuencia en nuestro hospital. Material y métodos: Estudio retrospectivo transversal, se revisaron expedientes de pacientes con diagnóstico de fractura en terreno patológico, atendidos en el período de Marzo de 2013 a Marzo de 2017. Resultados: Los tumores benignos que ocasionaron fracturas en terreno previamente dañado fueron: quiste óseo aneurismático 13, encondroma cinco, osteoma osteoide tres, tumor de células gigantes dos. Conclusión: En nuestra institución, los quistes óseos aneurismáticos fueron los tumores benignos que con mayor frecuencia producen fracturas patológicas en niños, con predominio en el sexo masculino.

Abstract: Introduction: A pathological fracture is defined as that which occurs through an abnormal bone. Approximately 20,000 benign neoplasms of the musculoskeletal system are diagnosed each year. Often the pain of the fracture is the first symptom of a pathological process in the bone. The site, age and radiographic appearance create a differential diagnosis for pathological fractures that remains broad. The clinical examination evaluates the condition of the skin, palpating any tissue mass and determining if there are local inflammatory signs such as erythema, heat or edema. The biopsy is highly recommended to confirm the diagnosis of a pathological fracture. Objective: To determine which benign bone tumors and pseudotumoral lesions produce fractures in children's bones more frequently in our institution. Material and methods: Cross-sectional retrospective study, review of records of patients with diagnosis of pathological fracture, attended in the period from March 2013 to March 2017, were reviewed. Results: The benign tumors that caused fractures in previously damaged areas were: aneurysmal bone cyst 13, enchondroma 5, osteoid osteoma 3, giant cell tumor 2. Conclusion: At our institution, aneurysmal bone cysts were the benign tumors that most frequently produce pathological fractures in children, with predominance in males.

Quiste óseo aneurismático en el húmero distal. Reporte de un caso y tratamiento actual / Aneurysmal bone cyst in distal humerus. Case report and current treatment

El quiste óseo aneurismático es una lesión ósea benigna que se presenta a edad temprana; su comportamiento suele ser agresivo por lo cual, la resección quirúrgica y la prevención de su recidiva son los pilares fundamentales de el tratamiento. Presentamos el caso de una paciente de 6 años de edad residente en Gualaceo, Ecuador, con masa de crecimiento progresivo y deformante en el codo izquierdo. Por las características de los exámenes de imagen y el cuadro sintomático se dignostica quiste óseo aneurismático que fue tratado con cirugía de resección intralesional y terapia adyuvante (fresado de alta velocidad, coagulación térmica y crioterapia). Se confirmó el diagnostico mediante el estudio histopatológico posquirúrgico

The aneurysmal bone cyst is a benign osseous lesion of presentation at an early age whose behavior is usually aggressive, so its surgical resection and the prevention of its recurrence is the fundamental pillar for the treatment. We present the case of a girl of 6 years of age living in Gualaceo, Ecuador, with a mass of progressive and deforming growth in the left elbow. By characteristics in the imaging tests and clinical picture it was considered as an aneurysmal bone cyst which was treated with intralesional resection surgery and adjuvant therapy (high speed burr, thermal coagulation and cryotherapy). The diagnosis was confirmed with postoperative histopathological study

Lingual mandibular bone defect: imaging features in panoramic radiograph, multislice computed tomography and magnetic resonance imaging / Defeito ósseo submandibular: características de imagem em radiografia panorâmica, tomografia computadorizada multislice e ressonância magnética

Stafne bone defect or mandibular bone depression is defined as a bone developmental defect usually filled with soft or salivary gland tissue. Lingual posterior variant incidence is less than 0.5%. We reported a case of an 80 years old Asian female asymptomatic patient who underwent routine panoramic radiographic examination and a radiolucent area in mandible was noticed as an incidental finding, with initial provisional diagnosis of traumatic bone cyst, aneurysmal bone cyst and lingual mandibular bone defect. The patient was then referred to multislice computed tomography and magnetic resonance imaging. Computed tomography showed a hypodense area with discontinuity in mandible base. Magnetic resonance imaging demonstrated a hyperintense image eroding mandibular body in contact with submandibular gland, which corresponded to fatty tissue and due to these imaging findings, the final diagnosis was lingual mandibular bone defect. Although the defect is a benign lesion and interventional treatment is not necessary, radiolucencies in mandible should be detailed investigated, due to their radiographic features that can resemble to other intrabony lesions. Imaging examinations can provide great defect details, especially magnetic resonance imaging, which can allow the identification of glandular tissue continuity to the mandibular defect.(AU)

O defeito ósseo do Stafne ou o defeito ósseo da mandíbula é definido como uma cavidade óssea geralmente preenchida com tecido glandular salivar. A incidência de variante lingual posterior é inferior a 0,5%. Neste relato, foi descrito um caso de paciente de paciente de 80 anos, etnia asiática e assintomática que foi submetida a exames radiográficos panorâmicos de rotina no qual observou-se incidentalmente uma área radiolúcida na mandíbula. Os diagnósticos iniciais foram de: cisto ósseo traumático, cisto ósseo aneurismático e defeito ósseo mandibular. A paciente foi encaminhada para realização de tomografia computadorizada multislice e ressonância magnética. A tomografia computadorizada mostrou uma área hipodensa com descontinuidade na base da mandíbula. A ressonância magnética demonstrou uma imagem hiperintensa no corpo da mandíbula, em contato com a glândula submandibular, correspondendo a tecido adiposo. Devido a estes achados imaginológicos, o diagnóstico final foi de defeito ósseo mandibular. Embora este defeito seja uma lesão benigna sem necessidade de tratamento intervencionista, as radiolucências na mandíbula, por conta de sua semelhança com outras lesões intraósseas, devem ser devidamente investigadas. Os exames de imagem podem fornecer detalhes do defeito, especialmente imagens de ressonância magnética, que podem permitir a identificação da continuidade do tecido glandular ao defeito mandibular.(AU)

Displasia fibrosa ósea / Fibrous dysplasia of bone

La displasia fibrosa ósea es un trastorno no hereditario del desarrollo esquelético caracterizado por una proliferación anormal de fibroblastos y diferenciación deficiente de osteoblastos que conduce a un reemplazo del tejido óseo esponjoso por tejido conectivo fibroso. Es producida por una mutación somática activadora del gen GNAS1 que induce una activación y proliferación de células mesenquimales indiferenciadas con formación de tejido fibroso y trabéculas óseas anómalas. Existen formas monostóticas, poliostóticas y craneofaciales con diversos grados de dolor, deformidades y fracturas óseas, aunque muchos casos son asintomáticos. En ocasiones se producen quistes óseos aneurismáticos, hemorragias, compromisos neurológicos y raramente osteosarcomas. Algunos casos se asocian a síndrome de McCune-Albright, síndrome de Mazabraud y a osteomalacia por hipofosfatemia por pérdida tubular renal inducida por el FGF23 producido por el tejido displásico. Los hallazgos en las radiografías convencionales son característicos, aunque variables y de carácter evolutivo. La gammagrafía ósea es la técnica de imagen con mayor sensibilidad para determinar la extensión de la enfermedad. El diagnóstico diferencial incluye múltiples lesiones óseas de características similares y en raras ocasiones se requiere biopsia ósea o estudio genético para confirmarlo. No existe un consenso unánime acerca del abordaje terapéutico de estos pacientes, razón por la cual es necesario un enfoque multidisciplinario. La conducta puede ser expectante o quirúrgica según el tipo de lesiones y es importante el manejo del dolor y de las endocrinopatías asociadas. La mayor experiencia publicada se refiere al uso de bifosfonatos y, más recientemente, denosumab. Los tratamientos actuales son insuficientes para modificar el curso de la enfermedad y es necesario el desarrollo de nuevas moléculas que actúen específicamente en el gen GNAS1 o sobre las células mesenquimales afectadas. (AU)

Fibrous dysplasia of bone is a noninherited developmental anomaly of bone characterized by abnormal proliferation of fibroblasts and differentiation of osteoblasts that cause a replacement of trabeculous bone by fibrous connective tissue. It is caused by a somatic mutation in the GNAS1 gene, which induces an undifferentiated mesenquimal cells activation and proliferation with formation of fibrous tissue and abnormal osseous trabeculae. There are monostotic, polyostotic and craniofacial variants with different grades of bone pain, deformities and fractures, although many cases remain asymptomatic. Aneurysmal bone cysts, bleeding, neurological compromise and infrequently osteosarcoma are possible complications. Some cases are associated to McCune-Albright syndrome, Mazabraud syndrome or hypophosphatemia and osteomalacia due to to renal tubular loss induced by FGF23 produced by dysplastic tissue. The findings on conventional radiography are characteristic although variable and evlolve with time. Bone scintigraphy is the most sensitive technique to evaluate the extent of disease. Differential diagnosis include several osseous lesions of similar appearance and, in some cases, bone biopsy or genetic testing may be necessary. Today, there is no consensus regarding the therapeutic approach for these patients and it is necessary a multidisciplinary medical team. Watchful waiting or surgical interventions can be indicated, depending on the type of bone lesions. Bone pain and associated endocrinopathies management are very important. Most published experience refers to the use of bisphosphonates and, more recently, denosumab. Current treatments are insufficient to modify the natural curse of the disease and therefore, new molecules with specific action on GNAS1 gene or affected mesenchymal cells are necessary. (AU)

Can ethanol be used as an adjuvant to extended curettage in order to reduce the recurrence rate of aneurysmal bone cyst? / O etanol pode ser usado como adjuvante na curetagem ampla a fim de reduzir a taxa de reincidência de cisto ósseo aneurismático?

ABSTRACT OBJECTIVE: The best treatment of aneurysmal bone cyst (ABC) is still unclear. This study aimed to evaluate the usefulness of extended curettage and ethanol as an adjuvant to reduce local recurrence of ABCs. METHODS: Retrospectively, 68 cases treated for primary and secondary ABCs caused by benign tumors from 2003 to 2013 were enrolled to a follow-up visit between one to ten years after the surgery. The treatment protocol was en-bloc resection, biopsy and curettage, extended curettage consisted of curettage, high-speed burring, ethanol 96%, and electrocauterization (combined four-step alcohol-using approach) followed by defect filling, consecutively. RESULTS: Among 36 patients with primary ABCs (16 male, 20 female, mean age of 16 years, range 3-46 years), 29 cases were treated with the combined four-step alcohol-using approach, four patients with resection, and three with biopsy and curettage. Thirty-two cases had secondary ABCs on benign lesions (17 male, 15 female). The recurrence rate was 5.88 in all primary and secondary ABC cases; two recurrences among 29 patients with primary ABCs (6.9%) and one recurrence among the 22 cases with secondary ABCs (4.5%). CONCLUSIONS: It could be suggested that the combined four-step alcohol-using approach may result in a very low recurrence rate of primary and secondary ABC lesions.

RESUMO OBJETIVO: Ainda não se sabe qual o melhor tratamento para cistos ósseos aneurismáticos (COA). Este estudo teve como objetivo avaliar a utilidade da curetagem estendida e do etanol como adjuvante para reduzir a reincidência local de COAs. MÉTODOS: Retrospectivamente, 68 casos que receberam tratamento para COAs primários e secundários causados por tumores benignos entre 2003 e 2013 foram chamados para uma consulta de seguimento, em um intervalo entre um e dez anos após a cirurgia. O protocolo de tratamento foi ressecção em bloco, biópsia e curetagem; a curetagem estendida consistiu em curetagem, broqueamento em alta velocidade, etanol 96% e eletrocauterização (abordagem combinada em quatro etapas com álcool), seguida do preenchimento do defeito, de forma consecutiva. RESULTADOS: Entre os 36 pacientes com COAs primárias (16 do sexo masculino, 20 do feminino, média de 16 anos, intervalo 3-46), 29 casos foram tratados com a abordagem combinada em quatro etapas com álcool, quatro pacientes com ressecção e três com biópsia e curetagem; 32 casos apresentavam COAs secundárias em lesões benignas (17 do sexo masculino, 15 do feminino). A taxa de reincidência foi de 5,88 em todos os casos de COAs primárias e secundárias; duas reincidências foram observadas entre 29 pacientes com COAs primária (6,9%) e uma reincidência entre os 22 casos (4,5%) de COAs secundária. CONCLUSÃO: Sugere-se que a abordagem combinada em quatro etapas com álcool pode resultar em uma taxa de reincidência muito baixa em lesões COAs primárias e secundárias.

Cisto ósseo aneurismático em tecido mole em um cão - relato de caso / Aneurysmal bone cyst in soft tissue in a dog - Case Report

Este trabalho descreve o diagnóstico e o tratamento instituído para um cão com um raro cisto ósseo aneurismático originado em tecido mole. O paciente foi apresentado para atendimento no Hospital de Clínicas Veterinárias da Universidade Federal do Rio Grande do Sul devido à dificuldade de locomoção, fraqueza nos membros pélvicos e disquesia havia 15 dias. Já estava recebendo tratamento medicamentoso sem sucesso. Ao exame clínico, notou-se aumento de volume sólido na região perineal direita, e foram solicitados exames complementares de imagem. A radiografia da região sugeriu hérnia perineal direita ou neoplasia. O cão foi encaminhado para cirurgia, na qual foi removida uma estrutura tumoral, arredondada, de aspecto ossificado. O exame histopatológico diagnosticou a estrutura como um cisto ósseo aneurismático em tecido mole, e o paciente recuperou-se totalmente após a excisão cirúrgica.(AU)

This paper describes the diagnosis and treatment of a dog with a rare aneurysmal bone cyst in soft tissue. The patient was attended in the Veterinary Clinic Hospital at the Fedral University of Rio Grande do Sul due to limited mobility, weakness in hind limbs, and dyschezia for 15 days. It was already receiving medical treatment without success. Upon clinical examination a solid increase volume in the right perineal region was detected, and complementary imaging tests were requested. Radiography of the region suggested right perineal hernia or neoplasia. The dog was submitted to surgery, and a rounded and ossified tumoral structure was removed. The histopathological exam diagnosed the structure as an aneurysmal bone cyst in soft tissue, and the patient recovered fully after surgical excision.(AU)