Predictive markers of response to neoadjuvant therapy in rectal cancer.

BACKGROUND: Neoadjuvant therapy followed by radical surgery is the standard treatment in locally advanced rectal cancer. It is important to predict the response because the treatment has side effects and is costly. The aim of this study was to establish the relationship among clinical, pathologic, and molecular biomarkers and the response to neoadjuvant therapy. METHOD: A total of 130 patients with locally advanced mid and low rectal cancer who underwent long-course radiotherapy with 5-FU based chemotherapy followed by radical surgical resection were included in the study. Clinical and pathologic data were collected. Paraffin-embedded sections obtained in diagnostic biopsies were assessed by immunohistochemical staining for molecular markers and classified using a semiquantitative method. Results were related with T-downstaging and tumor regression grade using Mandard scoring system on surgical specimens. RESULTS: Pathologic complete response was found in 19 patients (14.6%), while in another 18 (13.8%) only minor residual disease was seen in the rectal wall. T-downstaging was observed in 63 (48.5%). The average of lymph node retrieval in the surgical specimens was 9.4. Regarding predictive markers of response, there was significant correlation between the expression of B-cell lymphoma 2 (P = 0.005), ß-catenin (P = 0.03), vascular endothelial growth factor (P = 0.048) and apoptotic protease activating factor 1 (P = 0.03), tumor differentiation grade (P < 0.001), and response in the univariate analysis. T-downstaging was associated with vascular endothelial growth factor expression (P = 0.03) and tumor differentiation grade (P < 0.001). Significant parameters found in the multivariate analysis were tumor differentiation grade and Bcl-2 expression. CONCLUSIONS: Pathologic and molecular biomarkers in the diagnostic biopsies may help us predict tumor response to chemoradiation in rectal cancer patients.

Toll-like receptors 3, 4 and 9 in hepatocellular carcinoma: Relationship with clinicopathological characteristics and prognosis.

AIM: Hepatocellular carcinoma (HCC) is in the 10 leading cancer types, being difficult to detect as most of patients who develop this tumor have no symptoms other than those related to their long-standing liver disease. The liver is constantly exposed to bacterial products, viral infection, alcohol or other products, which may be the cause of chronic liver damage, and thus an increasing risk for HCC. Toll-like receptors (TLR) have gained an extraordinary interest in cancer research due to their role in several biological processes such as innate immune responses, the induction of adaptive immune responses, regulation of inflammation, would healing and carcinogenesis. Therefore, the aim of this study was to investigate the expression and clinical relevance of TLR3, 4 and 9 in HCC. METHODS: The expression levels of TLR3, TLR4 and TLR9 were analyzed in tumors from 30 patients with HCC. The analysis was performed by immunohistochemistry. Results were correlated with various clinicopathological findings and with overall survival. RESULTS: TLR3 was significantly high in large tumors (>4 cm in diameter) compared with small tumors (P < 0.05). Our results demonstrated that patients whose tumors showed both TLR4 and TLR9 positive immunostaining had poor prognosis. In addition, TLR9 expression by fibroblast-like cells was significantly associated with a shortened overall survival (P = 0.015). CONCLUSION: The results demonstrated an association between TLR3, TLR4 and TLR9 expression and tumor aggressiveness and poor prognosis in HCC.

Duodenal expression of Toll-like receptors and interleukins are increased in both children and adult celiac patients.

BACKGROUND: Toll-like receptors (TLRs) have achieved an extraordinary amount of interest in inflammatory diseases due to their role in the inflammatory activation. By activating the production of several biological factors, TLRs induce type I interferons and other cytokines, which drive the inflammatory response and activate the adaptive immune system. AIMS: The aim of this study was to investigate and compare the expression and clinical relevance of TLRs and interleukins in pediatric and adult celiac disease (CD), defined as intolerance to dietary proteins found in wheat, barley, and rye. METHODS: The expression levels of TLR3, TLR4, and TLR7, interleukins, and different transcription factors were analyzed on duodenal biopsies from ten children and 31 adults with CD, and 21 duodenal controls biopsies without CD (ten children and 11 adults). The analyses were performed by immunohistochemistry and real-time PCR. RESULTS: There were no significant differences in the studied parameters between adults and children. TLR4 expression level was increased twofold in CD specimens compared to controls. CD patients with high levels of TLR4 also showed high levels of interleukins (IL1, IL6, IL8, and IL17) as well as transcription factors (IRAK4, MyD88, and NF-κB). CONCLUSIONS: TLR4 expression is associated with CD independently of age at diagnosis. Pediatric patients and adult patients have a similar inflammatory profile, making it possible to treat both with the same immunological therapy in the future.

Sebaceous adenoma of the parotid gland.

Tumors of the salivary glands constitute an important field of oral and maxillofacial pathology. The majority of salivary gland neoplasms are benign, with malignant salivary tumors accounting for 15 to 32 percent. The most common site for salivary gland tumors is the parotid gland, accounting up to 80 percent of all cases. This article reports the pathologic picture in a case of sebaceous adenoma of the parotid gland. The tumor was composed of epithelial cells lining ducts and closely associated with broad areas of sebaceous differentiation. The growth pattern was predominantly cystic, with cavities filled with sebaceous material. Areas of oncocytic metaplasia were also seen. The presence of sebaceous glands in salivary neoplasms is frequent, however, and in spite of this, salivary neoplasms constituted partially or entirely of these cells are rarely observed. To the surgeon and pathologist, the major problem in dealing with sebaceous adenoma is the recognition of this rare entity, avoiding confusing with other more aggressive neoplasms. The treatment involves surgical excision. The addition of the current case to the previously published data brings the total number of parotid sebaceous adenoma to seven.

Response to chemoradiotherapy and lymph node involvement in locally advanced rectal cancer.

AIM: To establish the association between lymph node involvement and the response to neoadjuvant therapy in locally advanced rectal cancer. METHODS: Data of 130 patients with mid and low locally advanced rectal adenocarcinoma treated with neoadjuvant chemoradiation followed by radical surgery over a 5-year period were reviewed. Tumor staging was done by endorectal ultrasound and/or magnetic resonance imaging. Tumor response to neoadjuvant therapy was determined by T-downstaging and tumor regression grading (TRG). Pathologic complete response (pCR) is defined as the absence of tumor cells in the surgical specimen (ypT0N0). The varying degrees TRG were classified according to Mandard's scoring system. The evaluation of the response is based on the comparison between previous clinico-radiological staging and the results of pathological evaluation. χ (2) and Spearman's correlation tests were used for the comparison of variables. RESULTS: Pathologic complete response (pCR, ypT0N0, TRG1) was observed in 19 cases (14.6%), and other 18 (13.8%) had only very few residual malignant cells in the rectal wall (TRG2). T-downstaging was found in 63 (48.5%). Mean lymph node retrieval was 9.4 (range 0-38). In 37 cases (28.5%) more than 12 nodes were identified in the surgical specimen. Preoperative lymph node involvement was seen in 77 patients (59.2%), 71 N1 and 6 N2. Postoperative lymph node involvement was observed in 41 patients (31.5%), 29 N1 and 12 N2, while the remaining 89 were N0 (68.5%). In relation to ypT stage, we found nodal involvement of 9.4% in ypT0-1, 22.2% in ypT2 and 43.7% in ypT3-4. Of the 37 patients considered "responders" to neoadjuvant therapy (TRG1 and 2), there were only 4 N+ (10.8%) and the remainder N0 (89.2%). In the "non responders" group (TRG 3, 4 and 5), 37 cases were N+ (39.8%) and 56 (60.2%) were N0 (P < 0.001). CONCLUSION: Response to neoadjuvant chemoradiation in rectal cancer is associated with lymph node involvement.

Sentinel European Node Trial (SENT): 3-year results of sentinel node biopsy in oral cancer.

PURPOSE: Optimum management of the N0 neck is unresolved in oral cancer. Sentinel node biopsy (SNB) can reliably detect microscopic lymph node metastasis. The object of this study was to establish whether the technique was both reliable in staging the N0 neck and a safe oncological procedure in patients with early-stage oral squamous cell carcinoma. METHODS: An European Organisation for Research and Treatment of Cancer-approved prospective, observational study commenced in 2005. Fourteen European centres recruited 415 patients with radiologically staged T1-T2N0 squamous cell carcinoma. SNB was undertaken with an average of 3.2 nodes removed per patient. Patients were excluded if the sentinel node (SN) could not be identified. A positive SN led to a neck dissection within 3 weeks. Analysis was performed at 3-year follow-up. RESULTS: An SN was found in 99.5% of cases. Positive SNs were found in 23% (94 in 415). A false-negative result occurred in 14% (15 in 109) of patients, of whom eight were subsequently rescued by salvage therapy. Recurrence after a positive SNB and subsequent neck dissection occurred in 22 patients, of which 16 (73%) were in the neck and just six patients were rescued. Only minor complications (3%) were reported following SNB. Disease-specific survival was 94%. The sensitivity of SNB was 86% and the negative predictive value 95%. CONCLUSION: These data show that SNB is a reliable and safe oncological technique for staging the clinically N0 neck in patients with T1 and T2 oral cancer. EORTC Protocol 24021: Sentinel Node Biopsy in the Management of Oral and Oropharyngeal Squamous Cell Carcinoma.

Small cell undifferentiated carcinoma of the submandibular gland with neuroendocrine features.

This article reports the clinical, histopathologic, and immunohistochemical findings in a case of small cell undifferentiated carcinoma of the submandibular gland. The tumor was composed of anaplastic cells slightly larger than lymphocytes without ductal differentiation. On immunohistochemical analysis, the tumor contained cells that reacted positively with antibodies to cytokeratin, neuron-specific enolase, synaptophysin, and chromogranin. The present case supports the hypothesis that small cell undifferentiated carcinomas of the salivary glands arise from presumed multipotential ductal stem cells. When this tumor entity is located on the salivary glands, it appears to behave less aggressively than when it is a primary tumor of the bronchial tree.

Intestinal-type sinonasal adenocarcinomas. Immunohistochemical profile of 66 cases.

INTRODUCTION AND OBJECTIVES: Intestinal-type sinonasal adenocarcinomas are malignant epithelial tumours. Around 8-25% of all sinonasal malignant tumours are intestinal-type adenocarcinomas, which are related to wood dust exposure. Four histological subtypes have been described: papillary, colonic, solid and mucinous. We performed a pathological and immunohistochemical study in order to describe characteristics with prognostic, diagnostic and therapeutic value, and also to compare our results with previous studies. METHODS: Sixty six tumour samples were analysed and protein expression of p53, p16, E-cadherin, ß-catenin, epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2/neu) and cyclooxygenase-2 (COX-2) was performed by tissue microarray blocks. RESULTS: The 63% of cases were p53 positive; 37% showed nuclear staining with ß-catenin and 100% with E-cadherin, while 98% showed membrane staining with ß-catenin, 7% with EGFR, 8% with HER2/neu and 52% with COX-2; and 59% of the cases lost p16 expression. CONCLUSIONS: Intracranial invasion was the worst prognostic associated event. Solid and mucinous tumours were the most aggressive histological subtypes. Intracranial invasion was more frequent in mucinous subtype tumours. Immunohistochemical results were similar in all tumour subtypes, except for mucinous tumours, which showed weak expression of E-cadherin and ß-catenin. Comparing with previous studies, we found a lower expression of EGFR, HER2/neu and COX-2. The p16 expression was associated with worse survival and metastatic disease.

DNA methylation signatures identify biologically distinct thyroid cancer subtypes.

OBJECTIVE: The purpose of this study was to determine the global patterns of aberrant DNA methylation in thyroid cancer. RESEARCH DESIGN AND METHODS: We have used DNA methylation arrays to determine, for the first time, the genome-wide promoter methylation status of papillary, follicular, medullary, and anaplastic thyroid tumors. RESULTS: We identified 262 and 352 hypermethylated and 13 and 21 hypomethylated genes in differentiated papillary and follicular tumors, respectively. Interestingly, the other tumor types analyzed displayed more hypomethylated genes (280 in anaplastic and 393 in medullary tumors) than aberrantly hypermethylated genes (86 in anaplastic and 131 in medullary tumors). Among the genes indentified, we show that 4 potential tumor suppressor genes (ADAMTS8, HOXB4, ZIC1, and KISS1R) and 4 potential oncogenes (INSL4, DPPA2, TCL1B, and NOTCH4) are frequently regulated by aberrant methylation in primary thyroid tumors. In addition, we show that aberrant promoter hypomethylation-associated overexpression of MAP17 might promote tumor growth in thyroid cancer. CONCLUSIONS: Thyroid cancer subtypes present differential promoter methylation signatures, and nondifferentiated subtypes are characterized by aberrant promoter hypomethylation rather than hypermethylation. Additional studies are needed to determine the potential clinical interest of the tumor subtype-specific DNA methylation signatures described herein and the role of aberrant promoter hypomethylation in nondifferentiated thyroid tumors.

Adenomatosis hepática: una causa infrecuente de trasplante hepático / Hepatic adenomatosis: a rare cause of liver transplant

No disponible

[Non-secreting, extra-adrenal retroperitoneal paragangliomas]. / Paragangliomas retroperitoneales extradrenales no secretantes.

OBJECTIVE: Two cases of extra-adrenal non-secretory retroperitoneal paraganglioma in male patients are presented. The first case had intermittent vascular claudication in lower limbs and the second one was an incidental finding during staging of a lymphoma. METHODS: Both cases were studied using imaging techniques (US, CT and MRI) and histological and immunohistochemical analyses. RESULTS: The imaging techniques demonstrated solid homogeneous retroperitoneal masses intimately adhered to the abdominal aorta in the first case and located in the left upper hemiabdomen (in front of the left kidney) in the second one. Histological analysis showed a proliferation of spindle cells with cuboid cytoplasm arranged in solid nests, with typical immunohistochemical findings of paraganglioma. CONCLUSIONS: Extra-adrenal retroperitoneal paraganglioma are rare tumors, particularly the non-secretory variant. The only reliable criteria for malignancy are extensive capsular invasion and distant metastases.

Neck schwannomas.

Schwannomas are peripheral nerve tumours of nerve sheath origin. Twenty-five to 45 percent of extracranial schwannomas occur in the head and neck region. We present 2 cases of schwannomas that arise from the vagus and cervical plexus. These lesions are uncommon and most often present as asymptomatic solitary neck mass. Preoperative diagnosis can be difficult and conservative surgical excision remains the treatment of choice, often requiring sacrifice of a portion of the nerve.

Prognostic significance of p53 expression in oral squamous cell carcinoma without neck node metastases.

BACKGROUND: Aberrations of the p53 gene and overexpression of its protein are widely recognized markers of malignancy including oral squamous cell carcinomas. This study was performed to evaluate the relationship of immunoexpression of p53 protein in series of 91 squamous cell carcinomas of the oral cavity with clinicopathologic parameters and to investigate whether p53 immunoexpression might influence the clinical outcome of the disease. METHODS: From a group of 287 consecutive patients, 91 surgically treated ones were randomly selected. P53 protein expression was investigated by means of immunohistochemistry. Clinical and histopathologic data were gathered, and the patient survival was analyzed. RESULTS: Of the oral carcinomas, 52.7% (n = 48) overexpressed p53, using a threshold of 10% stained cell nuclei. There was a negative correlation of p53 immunoexpression with a histologic grade of differentiation (r = -0.236, p =.06) but not with clinical variables. Overall survival rate was 59% at 5 years. In univariate analysis, tumor size, node status, and advanced clinical stage were significantly associated with shortened overall survival. In patients without neck node metastases, p53 showed a strong correlation with survival (p =.01). In multivariate analysis performed only on N0 patients, tumor extension and p53 immunoexpression were found to be the only independent prognostic parameters with relative risks of 1.9 and 4.3, respectively. CONCLUSIONS: A strong relationship was observed between p53 immunoexpression and poor prognosis in patients with oral squamous cell carcinomas without neck node metastases.

Embolismo de líquido amniótico. Presentación de un caso / Amniotic fluid embolism. A case report

El embolismo de líquido amniótico (ELA) es un síndrome obstétrico que suele presentarse de manera abrupta en el parto o en el posparto inmediato, con un comienzo agudo de disnea o colapso cardiovascular. El ELA es difícil de diagnosticar en vida, ya que no existen pruebas analíticas específicas para la enfermedad. Presentamos un caso de ELA en una mujer de 37 años de edad que desarrolló un cuadro súbito de disnea y shock cardiovascular en el trabajo de parto. Se estableció la sospecha clínica de ELA y se procedió a una cesárea urgente. La paciente falleció, pero el feto sobrevivió. En la autopsia se demostró la presencia de componentes del líquido amniótico en los vasos del endocérvix uterino y los espacios alveolares pulmonares, confirmando la sospecha clínica(AU)

Amniotic fluid embolism (AFE) is a rare obstetric syndrome occurring abruptly during delivery or the postpartum characterized by acute onset of dyspnea or haemodynamic collapse. Clinical diagnosis is often difficult due to the lack of specific tests. We present a case of AFE in a 37-year-old woman who developed abrupt dyspnea and cardiogenic shock during labour. An emergency caesarian section was performed due to the suspicion of AFE. The patient died but the foetus survived. The autopsy revealed amniotic components within the endocervix vessels and lung alveolar spaces, thus confirming the clinical diagnosis(AU)

Adenocarcinomas nasosinusales tipo intestinal. Perfil inmunohistoquímico de 66 casos / Intestinal-type sinonasal adenocarcinomas. Immunohistochemical profile of 66 cases

Introducción y objetivos: Los adenocarcinomas nasosinusales tipo intestinal son tumores epiteliales malignos, que suponen el 8-25% de los tumores malignos nasosinusales. Se relacionan con la exposición al polvo de la madera. Se subdividen histológicamente en papilares, colónicos, sólidos y mucinosos. Realizamos un estudio patológico e inmunohistoquímico con el fin de establecer características con significado pronóstico, diagnóstico e incluso terapéutico, así como comparar con estudios previos. Métodos: Estudiamos 66 muestras tumorales mediante matrices tisulares. Realizamos tinciones inmunohistoquímicas para p53, p16, beta-catenina, E-cadherina, receptor del factor de crecimiento epidérmico (EGFR), receptor 2 de factor de crecimiento epidérmico humano (HER2/neu) y ciclooxigenasa 2 (COX-2). Resultados: Un 63% de los casos son positivos para p53, el 37% para beta-catenina nuclear, el 100% para E-cadherina, el 98% para beta-catenina membranosa, el 7% para EGFR, el 8% para HER2/neu, el 52% para COX-2 y el 59% pierden la expresión de p16. Conclusiones: La invasión intracraneal es el factor clínico pronóstico más importante. Los tumores de tipo sólido y mucinoso son los que muestran un comportamiento más agresivo, siendo los mucinosos los que mayor invasión intracraneal muestran. No existen diferencias inmunohistoquímicas entre los distintos subtipos histológicos, únicamente la tinción débil para E-cadherina y beta-catenina, más frecuente en los de tipo mucinoso. El EGFR, HER2/neu y COX-2 muestran una positividad menos frecuente que en series previas. La positividad para p16 se asocia a una menor supervivencia y mayor frecuencia de enfermedad metastásica.Palabras clave Adenocarcinoma nasosinusal. Carcinoma nasosinusal. Inmunohistoquímica. p53. p16. beta-catenina. E-cadherina. Receptor del factor de crecimiento epidérmico. Receptor 2 de factor de crecimiento epidérmico humano. Cyclooxigenasa-2 (AU)

Introduction and objectives: Intestinal-type sinonasal adenocarcinomas are malignant epithelial tumours. Around 8-25% of all sinonasal malignant tumours are intestinal-type adenocarcinomas, which are related to wood dust exposure. Four histological subtypes have been described: papillary, colonic, solid and mucinous. We performed a pathological and immunohistochemical study in order to describe characteristics with prognostic, diagnostic and therapeutic value, and also to compare our results with previous studies. Methods: Sixty six tumour samples were analysed and protein expression of p53, p16, E-cadherin, beta-catenin, epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2/neu) and cyclooxygenase-2 (COX-2) was performed by tissue microarray blocks. Results: The 63% of cases were p53 positive; 37% showed nuclear staining with beta-catenin and 100% with E-cadherin, while 98% showed membrane staining with beta-catenin, 7% with EGFR, 8% with HER2/neu and 52% with COX-2; and 59% of the cases lost p16 expression. Conclusions: Intracranial invasion was the worst prognostic associated event. Solid and mucinous tumours were the most aggressive histological subtypes. Intracranial invasion was more frequent in mucinous subtype tumours. Immunohistochemical results were similar in all tumour subtypes, except for mucinous tumours, which showed weak expression of E-cadherin and beta-catenin. Comparing with previous studies, we found a lower expression of EGFR, HER2/neu and COX-2. The p16 expression was associated with worse survival and metastatic disease (AU)

Adenoma sebáceo de la glándula parótida / Sebaceous adenoma of the parotid gland

Los tumores de las glándulas salivales constituyen un área importante de la patología oral y maxilofacial. La mayor parte de las neoplasias glandulares salivales son benignas, representando las malignas entre el 15 y el 32% del total. La localización más común de estas entidades es la glándula parótida, en la que asientan hasta el 80% de todos los casos. En este artículo se presenta un caso de adenoma sebáceo salival, de localización parotídea. El tumor, formado por células epiteliales que tapizan conductos, exhibe amplias áreas de diferenciación sebácea y zonas con metaplasia oncocítica. El patrón histológico es predominantemente quístico, observándose cavidades rellenas con material sebáceo. Si bien la presencia de glándulas sebáceas en las glándulas salivales es frecuente, las neoplasias exclusivamente formadas por las mismas son muy infrecuentes. Dada su rareza, este tumor plantea problemas diagnósticos diferenciales con otras entidades benignas y malignas. Su tratamiento implica la extirpación de la lesión, lo que generalmente involucra la eliminación de la glándula en la que ha surgido. El presente caso constituye el séptimo publicado de esta entidad

Tumors of the salivary glands constitute an important field of oral and maxillofacial pathology. The majority of salivary gland neoplasms are benign, with malignant salivary tumors accounting for 15 to 32 percent. The most common site for salivary gland tumors is the parotid gland, accounting up to 80 percent of all cases. This article reports the pathologic picture in a case of sebaceous adenoma of the parotid gland. The tumor was composed of epithelial cells lining ducts and closely associated with broad areas of sebaceous differentiation. The growth pattern was predominantly cystic, with cavities filled with sebaceous material. Areas of oncocytic metaplasia were also seen. The presence of sebaceous glands in salivary neoplasms is frequent, however, and in spite of this, salivary neoplasms constituted partially or entirely of these cells are rarely observed. To the surgeon and pathologist, the major problem in dealing with sebaceous adenoma is the recognition of this rare entity, avoiding confusing with other more aggressive neoplasms. The treatment involves surgical excision. The addition of the current case to the previously published data brings the total number of parotid sebaceous adenoma to seven

Metástasis tiroidea de un carcinoma de células renales. Hallazgos citológicos e histológicos / Renal cell carcinoma metastatic to the thyroid. Cytological and histological findings

Introducción: El carcinoma de células renales (CCR)tipo célula clara es un tumor maligno que puede metastatizaren múltiples localizaciones incluido el tiroides, con unabaja incidencia. Presenta una citología característica quepermite un rápido diagnóstico y tratamiento. Caso clínico:Presentamos el caso de una metástasis tiroidea por un CCRde células claras en un paciente de 67 años a los 12 años deldiagnóstico del tumor primario en el riñón derecho (AU)

Introduction: Clear cell type renal cell carcinoma(RCC) is a malignant tumor that can metastasize to manylocations –including the thyroid–, with a low incidence.Cytological features are characteristic enough to allow a fastdiagnosis and treatment. Case report:We report the case ofa thyroid metastasis of clear cell RCC in a 67-year oldpatient, 12 years after the diagnosis of the primary tumourin right kidney (AU)

Paragangliomas retroperitoneales extradrenales no secretantes / Etra-adrenal non-secretory retroperitoneal paraganglioma

Objetivo: Presentamos dos casos de paragangliomas extradrenales retroperitoneales no secretores en pacientes varones. El primer paciente consultó por un cuadro de claudicación intermitente en miembros inferiores y en el segundo fue un hallazgo incidental en el estadiaje de un linfoma. Método: Se realizaron estudios con técnicas de imagen (ecografía abdominal, TC y RM) y estudio anatomopatológico. Resultados: Los estudios de imagen confirmaron la existencia de masas retroperitoneales sólidas, homogéneas situadas en íntimo contacto con la aorta abdominal en el primer caso y en el hipocondrio izquierdo por delante del riñón en el segundo caso. El estudio histológico demostró una proliferación en nidos sólidos entrelazados de células fusiformes de citoplasma amplio, que tras estudio inmunohistoquímico fue tipificado como un paraganglioma. Conclusion: Los paragangliomas extradrenales retroperitoneales son tumores poco frecuentes, sobre todo en su variante no secretora. Los únicos indicadores fiables de malignidad son la invasión extensa de la cápsula y la diseminación metastásica a distancia (AU)