Primary retroperitoneal tumor: mucinous cystoadenocarcinoma / Tumor primario retroperitoneal: cistoadenocarcinoma mucinoso

Abstract Primary retroperitoneal mucinous cystadenocarci nomas (PRMCs) are extremely rare tumors with limited understanding of their pathogenesis and biological be havior. We describe a case of a 50-year-old female patient who underwent surgical treatment. The patient had a history of previous surgeries for mesenteric mucinous cystadenoma, without evidence of recurrence. During routine abdominal ultrasound a new tumor was found. An abdomen magnetic resonance imaging was done and confirmed the presence of a cystic lesion in the right iliac fossa. After discussion in multidisciplinary committee, surgical complete resection of the tumor, along with bilateral adnexectomy, was performed successfully. Histopathological examination revealed a mucinous adenocarcinoma adjacent to a mucinous cystadenoma. Immunohistochemical analysis supported the diagnosis of a primary retroperitoneal lesion. The patient had an uneventful recovery and has remained disease-free du ring the two-year postoperative follow-up. PRMCs are challenging to diagnose preoperatively due to nonspecific symptoms. Surgical excision is the mainstay of treatment. The long-term prognosis and op timal therapeutic strategies require further investigation.

Resumen Los cistoadenocarcinomas mucinosos primarios re troperitoneales (CMPR) son tumores extremadamente raros con una comprensión limitada de su patogénesis y comportamiento biológico. Describimos el caso de una mujer de 50 años some tida a tratamiento quirúrgico. La paciente tenía antece dentes de cirugías previas por cistodenoma mucinoso mesentérico, sin evidencia de recurrencia. Durante una ecografía abdominal de rutina se encontró un nuevo tumor. Se realizó una resonancia magnética abdomen que confirmó la presencia de una lesión quística en la fosa ilíaca derecha. Luego de discutir el caso en el comité multidisci plinario, se realizó con éxito la resección quirúrgica completa del tumor, junto con la anexectomía bilateral. El examen histopatológico reveló un adenocarcinoma mucinoso adyacente a un cistodenoma mucinoso. El análisis inmunohistoquímico apoyó el diagnóstico de lesión primaria retroperitoneal. La paciente tuvo una buena recuperación y permaneció libre de enfermedad durante dos años de seguimiento postoperatorio. Los CMPR son difíciles de diagnosticar debido a que presentan síntomas inespecíficos. La escisión quirúrgica es la base del tratamiento. El pronóstico a largo plazo y las estrategias terapéuticas óptimas requieren más investigación.

Primary retroperitoneal tumor: mucinous cystoadenocarcinoma.

Primary retroperitoneal mucinous cystadenocarcinomas (PRMCs) are extremely rare tumors with limited understanding of their pathogenesis and biological behavior. We describe a case of a 50-year-old female patient who underwent surgical treatment. The patient had a history of previous surgeries for mesenteric mucinous cystadenoma, without evidence of recurrence. During routine abdominal ultrasound a new tumor was found. An abdomen magnetic resonance imaging was done and confirmed the presence of a cystic lesion in the right iliac fossa. After discussion in multidisciplinary committee, surgical complete resection of the tumor, along with bilateral adnexectomy, was performed successfully. Histopathological examination revealed a mucinous adenocarcinoma adjacent to a mucinous cystadenoma. Immunohistochemical analysis supported the diagnosis of a primary retroperitoneal lesion. The patient had an uneventful recovery and has remained disease-free during the two-year postoperative follow-up. PRMCs are challenging to diagnose preoperatively due to nonspecific symptoms. Surgical excision is the mainstay of treatment. The long-term prognosis and optimal therapeutic strategies require further investigation.

Los cistoadenocarcinomas mucinosos primarios retroperitoneales (CMPR) son tumores extremadamente raros con una comprensión limitada de su patogénesis y comportamiento biológico. Describimos el caso de una mujer de 50 años sometida a tratamiento quirúrgico. La paciente tenía antecedentes de cirugías previas por cistodenoma mucinoso mesentérico, sin evidencia de recurrencia. Durante una ecografía abdominal de rutina se encontró un nuevo tumor. Se realizó una resonancia magnética abdomen que confirmó la presencia de una lesión quística en la fosa ilíaca derecha. Luego de discutir el caso en el comité multidisciplinario, se realizó con éxito la resección quirúrgica completa del tumor, junto con la anexectomía bilateral. El examen histopatológico reveló un adenocarcinoma mucinoso adyacente a un cistodenoma mucinoso. El análisis inmunohistoquímico apoyó el diagnóstico de lesión primaria retroperitoneal. La paciente tuvo una buena recuperación y permaneció libre de enfermedad durante dos años de seguimiento postoperatorio. Los CMPR son difíciles de diagnosticar debido a que presentan síntomas inespecíficos. La escisión quirúrgica es la base del tratamiento. El pronóstico a largo plazo y las estrategias terapéuticas óptimas requieren más investigación.

Maximizing Success: An Overview of Optimizing the Ovarian Tissue Transplantation Site.

Ovarian tissue cryopreservation and transplantation (OTCT) has emerged in recent years as a potential method for reversing abnormal endocrine and reproductive functions, particularly in patients receiving gonadotoxic cancer treatments having longer survival rates. From its first rodent experiments to human trials, OTCT has evolved tremendously, opening new windows for further utilization. Since then, significant progress has been achieved in terms of techniques used for surgical removal of the tissue, optimal fragment size, freezing and thawing procedures, and appropriate surgical sites for the subsequent reimplementation of the graft. In addition, various approaches have been proposed to decrease the risk of ischemic injury, which is the leading cause of significant follicle loss during neo-angiogenesis. This review aims to discuss the pros and cons of ovarian and retroperitoneal transplantation sites, highlighting the justifications for the viability and efficacy of different transplantation sites as well as the potential advantages and drawbacks of retroperitoneal or preperitoneal area.

[Desmoplastic round cell tumor]. / Tumor desmoplásico de células redondas.

Desmoplastic small round cell tumor is a rare and very aggressive neoplasm that belongs to the family of "small round blue cell tumors". It has a higher incidence in males in the second decade of life. It is due to translocation t(11;22) (p13;q12). It can be located both in the abdomen and in the retroperitoneum and is characterized by nonspecific symptoms. The treatment is very varied and the one that guarantees the total cure of the patient has not yet been detected. The objective of this study is to expose a clinical case of desmoplastic tumor as an rare abdominal disease and its imaging expression.

El tumor desmoplásico de células pequeñas y redondas es una neoplasia poco frecuente y muy agresiva que forma parte de la familia de los "tumores de células pequeñas, redondas y azules". Presenta una mayor incidencia en el sexo masculino en la segunda década de la vida. Se debe a la translocación t(11;22) (p13;q12). Se puede localizar tanto en el abdomen como en el retroperitoneo caracterizándose por presentar síntomas inespecíficos. El tratamiento es muy variado y no se ha detectado todavía aquel que garantice la cura total del paciente. El objetivo del presente estudio es exponer un caso clínico de tumor desmoplásico como enfermedad abdominal infrecuente y su expresión imagenológica.

Tumor desmoplásico de células redondas / Desmoplastic round cell tumor

Resumen El tumor desmoplásico de células pequeñas y redon das es una neoplasia poco frecuente y muy agresiva que forma parte de la familia de los "tumores de célu las pequeñas, redondas y azules". Presenta una mayor incidencia en el sexo masculino en la segunda década de la vida. Se debe a la translocación t(11;22) (p13;q12). Se puede localizar tanto en el abdomen como en el re troperitoneo caracterizándose por presentar síntomas inespecíficos. El tratamiento es muy variado y no se ha detectado todavía aquel que garantice la cura total del paciente. El objetivo del presente estudio es exponer un caso clínico de tumor desmoplásico como enfermedad abdo minal infrecuente y su expresión imagenológica.

Abstract Desmoplastic small round cell tumor is a rare and very aggressive neoplasm that belongs to the family of "small round blue cell tumors". It has a higher incidence in males in the second decade of life. It is due to trans location t(11;22) (p13;q12). It can be located both in the abdomen and in the retroperitoneum and is character ized by nonspecific symptoms. The treatment is very varied and the one that guarantees the total cure of the patient has not yet been detected. The objective of this study is to expose a clinical case of desmoplastic tumor as an rare abdominal disease and its imaging expression.

Giant myxoid retroperitoneal liposarcoma in a 41-year-old patient: A case report.

INTRODUCTION: Retroperitoneal Liposarcomas (RL) are a rare form of malignant tumors, they encompass just 5 % ot these and mainly present in female adults between 50 and 60 years of age. They can be divided into 4 morphological subtypes: 1) well-differentiated, 2) undifferentiated, 3) myxoid, and 4) pleomorphic. CASE PRESENTATION: 41-year-old male who present to the outpatient consult of oncological surgery after being diagnosed via imaging with a giant retroperitoneal liposarcoma. The patient reported unsuccessful weight loss attempts and subsequently noticed an increase in abdominal size as well as the development of ulcers in the lower limbs. He underwent radical resection, which included a right nephrectomy, as the primary treatment. DISCUSSION: Giant retroperitoneal liposarcomas are defined as those 30 cm in diameter or more or 20 kg or more in weight are considered "giants" and are extremely rare. The only treatment involves resection of the tumoration and those adjacent involved organs, and sometimes, uninvolved ones. Due to the high risk of recurrence, adjuvant therapy may be provided as well as imaging follow up. CONCLUSION: RL are a complicated entity to manage. They tend to present high rates of recurrence due to the difficulty of performing a full resection without positive margins. These patients should be thoroughly studied before surgery and appropriate follow-up should be provided.

Complex Vascular Resections for Retroperitoneal Soft Tissue Sarcoma.

Retroperitoneal sarcomas (RPSs) are locally aggressive tumors that can compromise major vessels of the retroperitoneum including the inferior vena cava, aorta, or main tributary vessels. Vascular involvement can be secondary to the tumor's infiltrating growth pattern or primary vascular origin. Surgery is still the mainstay for curing this disease, and resection of RPSs may include major vascular resections to secure adequate oncologic results. Our improved knowledge in the tumor biology of RPSs, in conjunction with the growing surgical expertise in both sarcoma and vascular surgical techniques, has allowed for major vascular reconstructions within multi-visceral resections for RPSs with good perioperative results. This complex surgical approach may include the combined work of various surgical subspecialties.

Leiomyosarcoma: Current Clinical Management and Future Horizons.

Leiomyosarcomas are soft tissue tumors that are derived from smooth muscle mainly in the pelvis and retroperitoneum. Percutaneous biopsy is paramount to confirm diagnosis. Imaging is necessary to complete clinical staging. Multimodal treatment should be directed by expert sarcoma multidisciplinary teams that see a critical volume of these rare tumors. Surgery is the mainstay of curative intent treatment; however due to its high metastatic progression, there may be a benefit for neoadjuvant systemic treatment. Adjuvant systemic treatment has no proven disease-free survival, and its main role is in the palliative setting to potentially prolong overall survival.

Giant retroperitoneal liposarcoma surgical management.

Retroperitoneal liposarcomas are very infrequent retroperitoneal malignant tumours. Most patients complain of palpable abdominal mass and only half present with abdominal pain. With haematogenous spread they can reach, mainly, lungs and liver, but only in 10% of cases. Here we report the presentation and surgical treatment of a giant massive retroperitoneal liposarcoma in a 53-year-old man.

Giant retroperitoneal liposarcoma surgical management.

Retroperitoneal liposarcomas are very infrequent retroperitoneal malignant tumours. Most patients complain of palpable abdominal mass and only half present with abdominal pain. With haematogenous spread they can reach, mainly, lungs and liver, but only in 10% of cases. Here we report the presentation and surgical treatment of a giant massive retroperitoneal liposarcoma in a 53-year-old man.

Leiomiosarcoma retroperitoneal con resección de vena cava / Retroperitoneal leiomyosarcoma with resection of the vena cava

RESUMEN El leiomiosarcoma vascular es un tumor maligno de baja incidencia cuya localización más frecuente es la vena vava inferior (VCI). Se presenta habitualmente en la 6a década de la vida. Según su localización se describen 3 tipos de acuerdo con su relación con las venas suprahepáticas y renales. Los cuadros clínicos de presentación son inespecíficos, ya que suelen debutar como hallazgos o con síndromes de congestión venosa pélvica/miembros inferiores. Su tratamiento quirúrgico radical requiere un equipo multidisciplinario entrenado en cirugía retrope ritoneal y vascular.

ABSTRACT Vascular leiomyosarcomas are rare tumors and are usually localized in the inferior vena cava (IVC). They usually occur in the 6th decade of life. They are classified into 3 groups according to the relation with the hepatic and renal veins. The clinical presentation is unspecific, ranging from an incidental finding to symptoms of venous pelvis congestion of lower extremity edema. Radical resection is the treatment of choice and requires multidisciplinary team trained in retroperitoneal and vascular surgery.

Extra-visceral retroperitoneal echinococcosis: case series with follow-up / Echinococosis retroperitoneal extra-visceral: serie de casos con seguimiento

SUMMARY: Extra-visceral retroperitoneal echinococcosis (EVRE), represents an infrequent condition, even in endemic areas. Its best treatment option is surgery. The aim of this study was to determine postoperative morbidity (POM) and recurrence in patients with EVRE, surgically treated. Case series with follow-up of patients with EVRE undergoing surgery consecutively at RedSalud Mayor Temuco Clinic, between 2008 and 2019. The outcome variables were POM and recurrence. Other variables of interest were cyst diameter, surgical time, and hospital stay. Descriptive statistics was used. In this study, 12 patients (75.0 % male), with a median age of 46 years, were treated. The 58.3 % of cases were primary retroperitoneal cysts. The median of cyst diameter, surgical time, and hospital stay were 15 cm, 95 min, and 4 days respectively. The most frequent type of resection was total cystectomy (58.3 %). MPO was 8.3 % (there was urinary infection in one patient). No reoperations were necessary. There was no operative mortality. With a median follow-up of 90 months, a recurrence of 8.3 % was verified (one case). The results achieved, in terms of POM and recurrence were similar to other series.

RESUMEN: La equinococosis retroperitoneal extravisceral (EREV), representa una condición poco frecuente, incluso en áreas endémicas. Su mejor opción de tratamiento es la cirugía. El objetivo de este estudio fue determinar morbilidad postoperatoria (MOP) y recurrencia de pacientes con EREV tratados quirúrgicamente. Serie de casos con seguimiento de pacientes con EREV intervenidos de forma consecutiva en Clínica RedSalud Mayor Temuco, entre 2008 y 2019. Las variables resultado fueron POM y recurrencia. Otras variables de interés fueron diámetro del quiste, tiempo quirúrgico y estancia hospitalaria. Se utilizó estadística descriptiva. Se trató a 12 pacientes (75,0 % hombres), con una mediana de edad de 46 años. El 58,3 % de los casos fueron quistes retroperitoneales primarios. La mediana del diámetro del quiste, tiempo quirúrgico y estancia hospitalaria fueron 15 cm, 95 min y 4 días, respectivamente. El tipo de resección más frecuente fue la quistectomía total (58,3 %). La MPO fue 8,3 % (infección urinaria en un paciente). No hubo reintervenciones ni mortalidad operatoria. Con una mediana de seguimiento de 90 meses, se verificó una recurrencia de 8,3 % (un caso). Los resultados obtenidos, en cuanto a MPO y recurrencia, son similares a otras series.

Neoplasia endocrina múltiple IIA: feocromocitoma bilateral. A propósito de un caso y revisión de la literatura / Multiple Endocrine Neoplasia IIA: Bilateral Pheochromocytoma. About a Case and Literature Review

Resumen: Presentamos el caso de una paciente del sexo femenino, de 54 años de edad, con antecedente familiar de neoplasia endocrina múltiple tipo II, con estudio genético positivo para NEM 2 IIA EXON 11, c634 CGCIB. Inició padecimiento con cardiopatía hipertensiva y disfunción diastólica, hallazgo to mográfico de tumor suprarrenal bilateral por imagenología, se realizó adrenalectomía convencional transabdominal, se encontró tumor derecho con cápsula correspondiente a feo cromocitoma con un peso de 1,100 g de 14.5 cm de diámetro mayor con invasión a cápsula sin romperla, tumor suprarrenal izquierdo correspondiente a feocromocitoma con un peso de 950 g de 15 cm de diámetro mayor.

Abstract: We present the case of a 54-year-old female patient with a family history of multiple endocrine neoplasia type II, with a genetic study for MEN 2 IIA EXON 11, CG6B c634, onset with hypertensive heart disease and diastolic dysfunction, tomographic finding of bilateral adrenal tumor by imaging. A conventional transabdominal adrenalectomy was performed, finding a right tumor with a capsule corresponding to pheochromocytoma with a weight of 1,100 g of 14.5 cm of greater diameter with invasion of the capsule without breaking it, and a left adrenal tumor corresponding to pheochromocytoma with a weight of 950 g of 15 cm of greater diameter.

Spontaneous retroperitoneal liposarcoma in a free-ranging juvenile golden-headed lion tamarin (Leontopithecus chrysomelas).

Malignant adipocytic neoplasia is rare among nonhuman primates. We report the gross and microscopic features of a retroperitoneal liposarcoma with myxofibrosarcoma-like dedifferentiation in a free-ranging juvenile golden-headed lion tamarin (Leontopithecus chrysomelas). To our knowledge, this is the first report of such tumor subtype in New World primates.

Schwannoma de retroperitoneo asociado a Neurofibromatosis tipo I / Retroperitoneal Schannoma associated to type I neurofibromatosis

Los Schwannomas son tumores de origen neural, corresponden al 1 por ciento de los tumores de retroperitoneo. En la mayoría de las ocasiones, son tumores de comportamiento benigno, encontrando que solo del 5 - 18 por ciento son malignos y aún menos frecuente es que sean de alto grado en su histología. Se trata de una paciente de 46 años de edad sin antecedentes crónico degenerativos. Con diagnóstico conocido de neurofibromatosis tipo I. Inició su padecimiento actual tres años previos a su ingreso en 2013, al presentar artralgia de rodilla derecha la cual se asocia a mialgias de forma ipsilateral. Se le solicitó como apoyo diagnostico una resonancia magnética de columna dorsal y lumbar, en la que se reporta una tumoración en la región del retroperitoneo de lado derecho con medidas de 10 x 17 cm con aparente origen espinal en L2 y L3. A pesar de ser masas de origen neural benignas la mayoría de las veces, no es infrecuente su malignización encontrando una cavidad con estructuras vecinas tomada por el tumor. En estos casos, es de vital importancia el manejo preoperatorio de manera multidisciplinaria tanto en la preparación preoperatoria, así como durante el procedimiento quirúrgico(AU)

Schwannomas are tumors of neural origin and account for 1 percent of retroperitoneal tumors. In many times, they are benign tumors and just 5 to 8 percent are malignant; high degree is even less frequent in its histology. This is a male patient aged 46 years with no history of chronic degenerative problems and diagnosis of type I neurofibromatosis. The disease appeared three years before his admission to hospital in 2013 because of right knee arthralgia associated to myalgias on the same side. Diagnostic support was requested in terms of performance of magnetic resonance of dorsal and lumbar spine; this test reported the presence of a tumor in the right side of the retroperitoneal region, it measured 10 x 17 cm with apparent spinal origin in L2 and L3. Although they are often masses of benign neural origin, their malignization is not rare. There was a cavity with adjoining structures affected by the tumor. In this type of cases, the preoperative management with multidisciplinary involvement both in the preoperative preparation and during the surgical procedure is of vital importance(AU)

Schwannomas mediastinal y retroperitoneal metacrónicos / Metachronous mediastinal and retroperitoneal schwannomas

Los schwannomas, también llamados neurilemomas, son tumores originados en la vaina de los nervios periféricos. El 45% ocurren en cabeza y cuello, solo el 9% en mediastino y el 0,7-2,7% en retroperitoneo. La multicentricidad es extremadamente rara. Presentamos el caso de un paciente de 30 años que consultó por dolor torácico derecho asociado a derrame pleural, al que se le diagnosticó un schwannoma mediastinal posterior, el cual fue resecado en forma completa por cirugía videoasistida. A los 3 años, vuelve a consultar por dolor en flanco derecho y, al estudiarlo, se constata un nuevo schwannoma de localización retroperitoneal, que se resecó por vía abierta dada su posición retrocava. Describimos la metodología de estudio de esta neoplasia y los hallazgos histopatológicos que demostraron su benignidad. Conclusión: es una patología muy infrecuente pero con excelente pronóstico posoperatorio si la resección quirúrgica es completa.

Schwannomas, also known as neurilemmoma, are neurogenic tumors that arise from the peripheral nerve sheaths. Forty-five percent of schwannomas occur in the head and neck, 9% in the mediastinum and 0.7-2.7% in the retroperitoneum. Multiple shwannomas are extremely rare. We report the case of a 30-year old male patient with chest pain in the right hemithorax associated with pleural effusion due to schwannoma of the posterior mediastinum that was completely resected with video-assisted thoracoscopy. Three years later, he presented pain on the right lumbar region due to a retroperitoneal schwannoma behind the vena cava that was completely removed with open surgery. We describe the tests used to evaluate this tumor and the histopathological findings confirming its benign nature. Conclusion: Schwannoma is a rare condition with excellent postoperative outcome after complete surgical resection.

Schwannoma de retroperitoneo asociado a Neurofibromatosis tipo I / Retroperitoneal Schannoma associated to type I neurofibromatosis

RESUMEN Los Schwannomas son tumores de origen neural, corresponden al 1 por ciento de los tumores de retroperitoneo. En la mayoría de las ocasiones, son tumores de comportamiento benigno, encontrando que solo del 5 - 18 por ciento son malignos y aún menos frecuente es que sean de alto grado en su histología. Se trata de una paciente de 46 años de edad sin antecedentes crónico degenerativos. Con diagnóstico conocido de neurofibromatosis tipo I. Inició su padecimiento actual tres años previos a su ingreso en 2013, al presentar artralgia de rodilla derecha la cual se asocia a mialgias de forma ipsilateral. Se le solicitó como apoyo diagnostico una resonancia magnética de columna dorsal y lumbar, en la que se reporta una tumoración en la región del retroperitoneo de lado derecho con medidas de 10 x 17 cm con aparente origen espinal en L2 y L3. A pesar de ser masas de origen neural benignas la mayoría de las veces, no es infrecuente su malignización encontrando una cavidad con estructuras vecinas tomada por el tumor. En estos casos, es de vital importancia el manejo preoperatorio de manera multidisciplinaria tanto en la preparación preoperatoria, así como durante el procedimiento quirúrgico(AU)

ABSTRACT Schwannomas are tumors of neural origin and account for 1 percent of retroperitoneal tumors. In many times, they are benign tumors and just 5 to 8 percent are malignant; high degree is even less frequent in its histology. This is a male patient aged 46 years with no history of chronic degenerative problems and diagnosis of type I neurofibromatosis. The disease appeared three years before his admission to hospital in 2013 because of right knee arthralgia associated to myalgias on the same side. Diagnostic support was requested in terms of performance of magnetic resonance of dorsal and lumbar spine; this test reported the presence of a tumor in the right side of the retroperitoneal region, it measured 10 x 17 cm with apparent spinal origin in L2 and L3. Although they are often masses of benign neural origin, their malignization is not rare. There was a cavity with adjoining structures affected by the tumor. In this type of cases, the preoperative management with multidisciplinary involvement both in the preoperative preparation and during the surgical procedure is of vital importance(AU)

Tumor fibroso solitario y síndrome Doege-Potter / Solitary fibrous tumor and Doege-Potter syndrome

El tumor fibroso solitario es raro. Si bien su localización más frecuente es la pleura, han sido informados algunos casos de ubicación retroperitoneal. Es difícil diferenciarlo imagenológicamente de otras neoplasias, por lo que casi siempre el diagnóstico es histológico. Dado que los tumores fibrosos solitarios tienen presentaciones clínicas muy diversas, una mejor compresión de la ubicación y sus características imagenológicas ayudaría a abreviar la lista de diagnósticos diferenciales. Comunicamos un tumor fibroso solitario de localización retroperitoneal cuyo diagnóstico fue confirmado por examen histológico.

The solitary fibrous tumor is uncommon. Even though it frequently locates in the pleura, a few cases have been reported in the retroperitoneum. Differentiation from other neoplasms is difficult, and therefore the diagnosis is always attained through histological examination. Although solitary fibrous tumors have variable clinical behaviors, a better comprehension of the location and its imaging characteristics would help to decrease the list of differential diagnoses. We report a solitary fibrous tumor located in the retroperitoneum whose diagnosis was confirmed by histological examination.

[Solitary fibrous tumor and Doege-Potter syndrome]. / Tumor fibroso solitario y síndrome Doege-Potter.

The solitary fibrous tumor is uncommon. Even though it frequently locates in the pleura, a few cases have been reported in the retroperitoneum. Differentiation from other neoplasms is difficult, and therefore the diagnosis is always attained through histological examination. Although solitary fibrous tumors have variable clinical behaviors, a better comprehension of the location and its imaging characteristics would help to decrease the list of differential diagnoses. We report a solitary fibrous tumor located in the retroperitoneum whose diagnosis was confirmed by histological examination.

Absceso del iliopsoas: Claves para el diagnóstico imagenológico / Iliopsoas abscess: Imaging keys to accurate diagnosis

Resumen: Si bien es infrecuente, el absceso del músculo iliopsoas exhibe una alta tasa de morbilidad y mortalidad. Su diagnóstico es difícil debido a las numerosas etiologías y su variada presentación clínica. Objetivo: Discutir las causas, vías de diseminación, diagnósticos diferenciales y manejo del absceso del iliopsoas, poniendo especial énfasis en el rol de la tomografía computada y la resonancia magnética en su diagnóstico. Conclusión: La evaluación con estudios de imagen es esencial para determinar la complejidad, extensión y origen anatómico de esta patología, parámetros que son fundamentales para determinar el pronóstico y el manejo en este tipo de pacientes.

Abstract: Although rare, iliopsoas abscess has a high rate of morbidly and mortality. Its diagnosis is diffiult given the numerous etiologies and varied clinical presentation. Objective: To discuss the causes, dissemination pathways, differential diagnoses and management of iliopsoas abscess; emphasizing the important role of CT and MR through multiple imaging examples. Conclusion: Imagenological analysis is essential to determine complexity, extention, and anatomical origin of this condition, fundamental parameters in the prognosis and management of these patients.