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.

Pronóstico y supervivencia de pacientes diagnosticados de liposarcoma retroperitoneal bien diferenciado y desdiferenciado / Prognosis and survival of patients diagnosed with well-differentiated and dedifferentiated retroperitoneal liposarcoma

Objetivos: El objetivo principal es determinar la supervivencia global y la supervivencia libre de enfermedad de pacientes intervenidos de liposarcoma retroperitoneal, comparándolos en función de los subtipos histológicos bien diferenciado y desdiferenciado. Los objetivos secundarios son analizar descriptivamente las características clínicas de estos pacientes e identificar otras variables independientes que puedan modificar significativamente estos perfiles de supervivencia.MétodosSe realiza un estudio observacional y analítico mediante una cohorte histórica retrospectiva, seguida prospectivamente. Los criterios de inclusión fueron: cirugía de liposarcoma de localización retroperitoneal, subtipos histológicos bien diferenciado y desdiferenciado, entre enero de 2002 y mayo de 2019. Se incluyeron un total de 32 pacientes. Se utilizó el estimador de Kaplan-Meier para resumir los datos y la prueba log-rank para el análisis comparativo.ResultadosLa supervivencia global a los 5 años fue del 59%. No se encontraron diferencias entre los pacientes con subtipo bien diferenciado con respecto al desdiferenciado (p=0,834). La supervivencia libre de enfermedad a los 2 años fue del 59% en los bien diferenciados y del 26% en los desdiferenciados, siendo estas diferencias estadísticamente significativas (p=0,005). Ninguna de las otras variables estudiadas modificó significativamente estos perfiles de supervivencia.ConclusionesLa supervivencia libre de enfermedad de los liposarcomas retroperitoneales desdiferenciados es significativamente menor que en los bien diferenciados, pero no puede afirmarse que haya diferencias en la supervivencia global (AU)

Objectives: The main objective is to establish the overall survival and disease-free survival profiles regarding the patients with retroperitoneal liposarcoma, making a comparison based on the well-differentiated and dedifferentiated histological subtypes. The secondary objectives are to descriptively analyze the clinical characteristics of said patients and to identify and analyze other independent variables that might modify these survival profiles significantly.MethodsAn observational and analytical study was performed using a retrospective historical cohort that was followed prospectively. The inclusion criteria consisted of: the procedure of liposarcoma located in the retroperitoneum, the well-differentiated and dedifferentiated histological subtypes, between January 2002 and May 2019. As a result, 32 patients took part in this study's sample. Kaplan–Meier estimator was used to summarize the results and log-rank test was used in the comparative analysis.ResultsThe overall survival at 5 years was around 59%. No differences were found between the patients with a well-differentiated subtype compared to the dedifferentiated ones (p=0.834). The disease-free survival at 2 years was 59% regarding the well-differentiated and 26% regarding the dedifferentiated, with these differences being statistically significant (p=0.005). None of the other studied variables modified these survival profiles significantly.ConclusionsDedifferentiated retroperitoneal liposarcomas show less disease-free survival than well-differentiated liposarcomas. However, regarding overall survival no differences can be claimed (AU)

Prognosis and survival of patients diagnosed with well-differentiated and dedifferentiated retroperitoneal liposarcoma.

OBJECTIVES: The main objective is to establish the overall survival and disease-free survival profiles regarding the patients with retroperitoneal liposarcoma, making a comparison based on the well-differentiated and dedifferentiated histological subtypes. The secondary objectives are to descriptively analyze the clinical characteristics of said patients and to identify and analyze other independent variables that might modify these survival profiles significantly. METHODS: An observational and analytical study was performed using a retrospective historical cohort that was followed prospectively. The inclusion criteria consisted of: the procedure of liposarcoma located in the retroperitoneum, the well-differentiated and dedifferentiated histological subtypes, between January of 2002 and May of 2019. As a result, 32 patients took part in this study's sample. Kaplan-Meier estimator was used to summarise the results and log-rank test was used in the comparative analysis. RESULTS: The overall survival at 5 years was around 59%. No differences were found between the patients with a well-differentiated subtype compared to the dedifferentiated ones (p = 0.834). The disease-free survival at 2 years was 59% regarding the well-differentiated and 26% regarding the dedifferentiated, with these differences being statistically significant (p = 0.005). None of the other studied variables modified these survival profiles significantly. CONCLUSIONS: Dedifferentiated retroperitoneal liposarcomas show less disease-free survival than well-differentiated liposarcomas. However, regarding overall survival no differences can be claimed.

Prognosis and survival of patients diagnosed with well-differentiated and dedifferentiated retroperitoneal liposarcoma. / Pronóstico y supervivencia de pacientes diagnosticados de liposarcoma retroperitoneal bien diferenciado y desdiferenciado.

OBJECTIVES: The main objective is to establish the overall survival and disease-free survival profiles regarding the patients with retroperitoneal liposarcoma, making a comparison based on the well-differentiated and dedifferentiated histological subtypes. The secondary objectives are to descriptively analyze the clinical characteristics of said patients and to identify and analyze other independent variables that might modify these survival profiles significantly. METHODS: An observational and analytical study was performed using a retrospective historical cohort that was followed prospectively. The inclusion criteria consisted of: the procedure of liposarcoma located in the retroperitoneum, the well-differentiated and dedifferentiated histological subtypes, between January 2002 and May 2019. As a result, 32 patients took part in this study's sample. Kaplan-Meier estimator was used to summarize the results and log-rank test was used in the comparative analysis. RESULTS: The overall survival at 5 years was around 59%. No differences were found between the patients with a well-differentiated subtype compared to the dedifferentiated ones (p=0.834). The disease-free survival at 2 years was 59% regarding the well-differentiated and 26% regarding the dedifferentiated, with these differences being statistically significant (p=0.005). None of the other studied variables modified these survival profiles significantly. CONCLUSIONS: Dedifferentiated retroperitoneal liposarcomas show less disease-free survival than well-differentiated liposarcomas. However, regarding overall survival no differences can be claimed.

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.

[Giant lipomas or retroperitoneal liposarcomas? Controversies in their diagnosis and treatment]. / ¿Lipoma gigante o liposarcoma retroperitoneal? Controversias en su diagnóstico y tratamiento.

BACKGROUND: Retroperitoneal lipomas are extremely rare tumors that must be differentiated from well-differentiated liposarcomas (WD-LPS). OBJECTIVES: To summarize the evidence about giant retroperitoneal lipomas or liposarcomas; and to elaborate recommendations for their management. DATA SOURCES: A systematic literature search from January 1985 to December 2019 and a review of our own cases was performed. RESULTS: Our series comprises four patients, two females and two males. The diagnosis was incidental in two cases. The medium size was 26 cm, being two cases located exclusively in the retroperitoneum, one in the inguinal region and one in the buttock via pelvic space. All cases were surgically removed being confirmed the initial diagnosis of retroperitoneal lipomas in two cases, as the rest two cases were classified as WD_LPS after MDM2/CDK4 genetic analysis. The review of the available literature plus our own cases revealed 30 cases, of which 58% were woman. Only two cases were asymptomatic. The main symptom was abdominal mass (53%) followed by abdominal pain (40,6%). The median size of the lesions was 24,9 cm with a median weight of 4.576,3 g. All cases were surgically removed, being necessary to remove contiguous organs in only four cases (12,5%). CONCLUSIONS: Retroperitoneal lipoma is a rare tumor which must be differentiated from WD-LPS. This is a very difficult task, being necessary to determinate MDM2 status (by FISH or MLPA), present in liposarcoma but not in lipomas, for its correct diagnosis. The treatment must be based on a complete surgical resection with negative margins.

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.

Paravertebral lipomatous ganglioneuroma with intraspinal extension. Case report and literature review. / Ganglioneuroma lipomatoso paravertebral con extensión intraespinal. Descripción de un caso y revisión de la literatura.

Lipomatous ganglioneuromas are a rare variant of ganglioneuromas characterized by a mature adipocytic component admixed with a conventional ganglioneuroma component. We present the case of a 34 year old patient with a paravertebral right lesion L1-L4 with intraspinal extension and secondary neurological deficit, who underwent surgery in our hospital. The pathological anatomy showed a yellowish encapsulated neoplasm, which under microscopic evaluation showed areas of ganglioneuroma admixed with areas of mature fat. In the follow up, the patient was asymptomatic, had recovered paresis in the right lower extremity and in the last image control did not present data of lesion recurrence. Fewer than 10 cases of lipomatous ganglioneuromas have been reported in the literature, being this the first paravertebral case wih intraspinal extension and with neurological deficit, hence the interest of this work.

Update in pelvic and retroperitoneal sarcoma management: The role of compartment surgery. / Actualización en el manejo de sarcomas retroperitoneales y pélvicos; el papel de la cirugía compartimental.

Surgery for retroperitoneal sarcomas should be "en bloc" compartmental, which involves resection of unaffected organs. Its upfront use is key, providing a high percentage of resections with negative margins, resulting in a better local control and increased survival in many patients. Preservation of organs should be done in an individualized manner, especially in the pelvic location, and adapted to the histological aggressiveness of the tumor. Preoperative biopsy is able to establish the diagnosis of sarcoma subtype and consequently an adequate perioperative strategy. These patients should be managed by expert surgeons at referral centers with multidisciplinary units and oncology committees. The use of chemotherapy and radiotherapy is not yet well defined, so it is only recommended at referral centers with clinical trials. Currently, this is the only option to offer the best morbidity and mortality rates, as well as possible improvements in the survival of these patients.

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)

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

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)

Risk factors of early recurrence in retroperitoneal liposarcoma. / Factores de riesgo implicados en la recurrencia precoz del liposarcoma retroperitoneal.

INTRODUCTION: The aim of this study is to identify factors associated to recurrence and survival in primary retroperitoneal liposarcomas. METHODS: Prospective database of 35 patients with primary retroperitoneal liposarcoma treated 2004-2015 were retrospectively analyzed. Exclusion criteria were recurrent and metastatic tumors. Overall survival (OS) and disease-free survival were reviewed. Patient data were compared between patients with or without recurrence within 12 months after surgery. Risk factors were determined using logistic regression analysis. RESULTS: Five-year OS was 61.1%. One and three-year disease-free survival were 68.6% and 17.1% respectively. OS in the early recurrence group was 36.4 months compared with 43.2 months in the group without early recurrence (P=.011). Early recurrence was associated with a reduction in OS (HR=4.05; CI95%: 1.27-12.96; P=.018). Multifocality and microscopic positive margins R1 were associated with early recurrence. Histologic subtype, margin of resection, histologic grade and multifocality were factors associated with recurrence. Contiguously involved organ resection had a beneficial effect on early recurrence and was associated with an increase in disease-free survival and OS. Adjuvant treatments had no protective effect on recurrence. CONCLUSIONS: This study underlines the crucial role aggressive surgical approach in retroperitoneal Liposarcoma treatment, especially in those patients with histological characteristics that adversely the prognosis.

Approach and Management of Traumatic Retroperitoneal Injuries. / Abordaje y manejo de las lesiones retroperitoneales traumáticas.

Traumatic retroperitoneal injuries constitute a challenge for trauma surgeons. They usually occur in the context of a trauma patient with multiple associated injuries, in whom invasive procedures have an important role in the diagnosis of these injuries. The retroperitoneum is the anatomical region with the highest mortality rates, therefore early diagnosis and treatment of these lesions acquire special relevance. The aim of this study is to present current published scientific evidence regarding incidence, mechanism of injury, diagnostic methods and treatment through a review of the international literature from the last 70 years. In conclusion, this systematic review showed an increasing trend towards non-surgical management of retroperitoneal injuries.

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.

Schwannoma benigno de vía excretora renal / Benign schwannoma of renal excretory

Los tumores del retroperitoneo pueden ser malignos o benignos y se clasifican según el tejido donde se originan. Entre ellos, los tumores renales son los que cobran cada día mayor representatividad, en especial, el carcinoma renal de células claras, en sus disímiles formas de presentación clínica, incluyendo un numeroso grupo de pacientes asintomáticos. Se presentó el caso de una paciente femenina con dolor lumbo-abdominal izquierdo de carácter gravativo asociado a infecciones urinarias periódicas, de varios meses de evolución. Mediante ultrasonido halló una imagen compleja, predominantemente quística, en el polo superior del riñón izquierdo con elementos sólidos en su interior y finos tabiques, que no descartaba la posibilidad de un carcinoma variedad quística; después de ser sometida al tratamiento quirúrgico, el estudio histológico del tumor se demostró que se trataba de un schwannoma de cavidades renales, tipo benigno. La evolución de la paciente ha sido satisfactoria.

Retroperitoneal tumors can be malignant or benign and they are classified according to the tissue where they are originated. Among them, kidney tumors are those that are becoming increasingly representative, particularly renal clear cell carcinoma, in their different forms of clinical presentation, including a large group of asymptomatic patients. The case of a female patient with left lumbo-abdominal pain is presented, associated with recurrent urinary tract infections, several months of evolution. By ultrasound, one predominantly cystic complex picture was found in the upper pole of the left kidney with solid elements inside and thin walls, which did not rule out the possibility of a variety cystic carcinoma; after being subjected to surgical treatment, tumor histology showed that it was schwannoma of renal cavities, benign type. The evolution of this patient was successful.

Schwannoma benigno de vía excretora renal / Benign schwannoma of renal excretory

Los tumores del retroperitoneo pueden ser malignos o benignos y se clasifican según el tejido donde se originan. Entre ellos, los tumores renales son los que cobran cada día mayor representatividad, en especial, el carcinoma renal de células claras, en sus disímiles formas de presentación clínica, incluyendo un numeroso grupo de pacientes asintomáticos. Se presentó el caso de una paciente femenina con dolor lumbo-abdominal izquierdo de carácter gravativo asociado a infecciones urinarias periódicas, de varios meses de evolución. Mediante ultrasonido halló una imagen compleja, predominantemente quística, en el polo superior del riñón izquierdo con elementos sólidos en su interior y finos tabiques, que no descartaba la posibilidad de un carcinoma variedad quística; después de ser sometida al tratamiento quirúrgico, el estudio histológico del tumor se demostró que se trataba de un schwannoma de cavidades renales, tipo benigno. La evolución de la paciente ha sido satisfactoria(AU)

Retroperitoneal tumors can be malignant or benign and they are classified according to the tissue where they are originated. Among them, kidney tumors are those that are becoming increasingly representative, particularly renal clear cell carcinoma, in their different forms of clinical presentation, including a large group of asymptomatic patients. The case of a female patient with left lumbo-abdominal pain is presented, associated with recurrent urinary tract infections, several months of evolution. By ultrasound, one predominantly cystic complex picture was found in the upper pole of the left kidney with solid elements inside and thin walls, which did not rule out the possibility of a variety cystic carcinoma; after being subjected to surgical treatment, tumor histology showed that it was schwannoma of renal cavities, benign type. The evolution of this patient was successful(AU)

[Retroperitoneal mucinous cystadenocarcinoma presenting seven years after appendectomy and right hemicolectomy]. / Cistoadenocarcinoma mucinoso retroperitoneal ocurrido a los 7 años de apendicectomía y hemicolectomía derecha.

Retroperitoneal mucinous cystadenocarcinoma (RMC) with no involvement of neighboring structures is very rare, regardless of whether the lesion is primary or secondary. We report the case of a patient who presented RMC seven years after appendectomy and right hemicolectomy. We discuss both diagnostic possibilities.

Tumor extragonadal de células de la granulosa / Extragonadal granulosa cell tumor

Los tumores extragonadales de la granulosa son extremadamente infrecuentes. Originados a lo largo del recorrido de las gónadas en formación durante su evolución embriológica, se presentan fundamentalmente en la mujer perimenopáusica. Son por lo general tumores de bajo grado de malignidad con recurrencia frecuente. Se estudió a una paciente de 51 años que evolucionó durante más de 10 años con muy pocos síntomas y un crecimiento lento hasta alcanzar 20 cm en el retroperitoneo. La intervención realizada fue satisfactoria(AU)

Extragonadal granulosa cell tumors are extremely infrequent. Originated along the path of the gonads in their formation during embryologic evolution, they are mainly present in the perimenopausal woman. Generally, they are tumors with a low degree of malignancy and frequent recurrence. A 51 year - old patient was studied who, for more than 10 years, presented few symptoms and a slow growth, reaching 20 cm in the retroperitoneum. The surgical procedure performed was satisfactory(AU)