Metanephric adenoma: molecular study and review of the literature.

INTRODUCTION: Metanephric adenoma (MA) is an uncommon benign tumor accounting for 0.2-0.7% of adult renal epithelial neoplasms. The clinical course is often indolent, but diagnosis should not be delayed since clinical symptoms (hematuria, fever, palpable abdominal mass, and flank pain) may be non-specific and overlap with those of a malign renal neoplasm. We report on 4 cases of AM, for which morphological and mutational analysis were performed. MATERIAL AND METHODS: Immunohistochemical staining was performed on sections cut from paraffin blocks to assess expression of WT1, vimentin, racemase, CK7, CD10 and RCC. Testing for the BRAF gene mutation V600 was carried out using real-time PCR (Cobas® 4800). RESULTS: In all four cases, tumors were visible as well-circumscribed, non-encapsulated masses located in the renal cortex and extending towards the medulla. At immunohistochemical examination, tumor cells stained negative for CK7, CD10 and RCC and positive for both WT1 (nuclear, intense) and vimentin (cytoplasmic, intense, and diffuse). Molecular analysis revealed the BRAF gene mutation V600E in three cases and wild-type BRAF in the fourth. CONCLUSIONS: BRAF molecular mutation analysis may aid diagnosis in cases with atypical histological features, especially in small incisional biopsies when reassessment of surgical treatment may be considered.

An Unusual Case of Desmoplastic Melanoma With Monster Cells Imitating an Atypical Fibroxanthoma.

Numerous cells with very large and irregular nuclei ("monster" cells) have not hitherto been reported in desmoplastic melanoma (DM). Their prognostic significance in melanomas is a matter of debate, although some authors have associated them with more aggressive tumor behavior. We report a mixed DM on the scalp of an 88-year-old woman imitating an atypical fibroxanthoma. Tumor cells stained positive for SOX10, S100, and cyclin D1; BRAF mutation status was negative, and fluorescence in situ hybridization analysis showed copy number gains in 11q13 (cyclin D1) and 6p25 (RREB1), and loss in 6q23 (MYB). Cyclin D1 amplification is associated with poor prognosis in melanoma.

Mitotic count: A need for standardization / Recuento mitótico: una necesidad de estandarización

PURPOSE: The mitotic count (MC), number of mitosis per unit area, is a very important parameter frequently used for classification and grading of some tumors. Traditionally, the MC has been expressed in terms of number of mitoses per high power field. The size of the field of view can vary greatly among different microscopes. In order to avoid under or overestimation of mitotic count, a conversion needs to be made. METHODS: A simple formula based on a simple rule of three has been devised to standardize the mitotic count to the reference area by multiplying the number of mitotic figures by a correction factor which has been calculated for the most frequently used microscopes and various common tumors. RESULTS AND CONCLUSIONS: We propose this simple method, which involves only a single multiplication, to standardize the mitotic count to the reference area

OBJETIVO: El recuento mitótico o número de mitosis por unidad de área, es un parámetro muy importante utilizado frecuentemente para clasificar y estadificar ciertos tumores. Tradicionalmente se ha expresado el recuento mitótico en términos de número de mitosis por campos de alta frecuencia. El tamaño del campo de visión puede variar ampliamente entre los diferentes microscopios. A fin de evitar la infraestimación o sobreestimación del recuento mitótico, debe realizarse una conversión. MÉTODOS: Por medio de una simple regla de tres, se ha obtenido una fórmula simple para estandarizar el recuento mitótico. Multiplicando el número de mitosis por un factor de corrección, se obtiene el recuento mitótico estandarizado al área de referencia. Se han calculado los factores de corrección para los microscopios más habituales y para los diferentes tumores comunes. RESULTADOS Y CONCLUSIONES: Proponemos este método simple (únicamente uno por multiplicación) para estandarizar el recuento mitótico con respecto al área de referencia

Mitotic count: A need for standardization.

PURPOSE: The mitotic count (MC), number of mitosis per unit area, is a very important parameter frequently used for classification and grading of some tumors. Traditionally, the MC has been expressed in terms of number of mitoses per high power field. The size of the field of view can vary greatly among different microscopes. In order to avoid under or overestimation of mitotic count, a conversion needs to be made. METHODS: A simple formula based on a simple rule of three has been devised to standardize the mitotic count to the reference area by multiplying the number of mitotic figures by a correction factor which has been calculated for the most frequently used microscopes and various common tumors. RESULTS AND CONCLUSIONS: We propose this simple method, which involves only a single multiplication, to standardize the mitotic count to the reference area.

Dermatofibrosarcoma protuberans en región perianal: estudio de un caso, revisión y actualización / Perianal dermatofibrosarcoma protuberans: a case report, review and update

El dermatofibrosarcoma protuberans es un sarcoma de bajo grado que típicamente se origina en dermis con extensión local a tejido celular subcutáneo y músculo. Presentamos un dermatofibrosarcoma protuberans perianal en un varón de 41 años que le ocasionaba proctalgia y estreñimiento, y revisamos la literatura científica. El interés del caso reside fundamentalmente en la excepcionalidad de que un dermatofibrosarcoma protuberans se presente en región perianal (solo 2 casos previamente descritos) y en esa línea, en la dificultad del manejo quirúrgico en dicha topografía. El reordenamiento t(17;22)(q22;q13) con el resultado de la fusión génica COL1A1/PDGFß en estos tumores no solo es una característica de utilidad diagnóstica; también, otorga una alternativa terapéutica en casos inoperables o metastásicos con el uso de imatinib

Dermatofibrosarcoma protuberans is a low-grade sarcoma typically originating in the dermis but with local invasion of subcutaneous cell and muscle tissue. We report a case of perianal dermatofibrosarcoma protuberans in a 41-year-old male complaining of anal pain and constipation. To date, only two cases of perianal dermatofibrosarcoma protuberans have been reported. The unusual location hinders surgical treatment. The characteristic translocation t(17;22)(q22;q13) leading to the formation of COL1A1/PDGFß fusion transcripts is not only of diagnostic value but also enables an alternative imatinib-based therapy in inoperable or metastatic cases. The pertinent literature is reviewed

Tumor de células gigantes primario de pulmón / Primary Pulmonary Giant Cell Tumor

No disponible

[Perianal dermatofibrosarcoma protuberans: a case report, review and update]. / Dermatofibrosarcoma protuberans en región perianal: estudio de un caso, revisión y actualización.

Dermatofibrosarcoma protuberans is a low-grade sarcoma typically originating in the dermis but with local invasion of subcutaneous cell and muscle tissue. We report a case of perianal dermatofibrosarcoma protuberans in a 41-year-old male complaining of anal pain and constipation. To date, only two cases of perianal dermatofibrosarcoma protuberans have been reported. The unusual location hinders surgical treatment. The characteristic translocation t(17;22)(q22;q13) leading to the formation of COL1A1/PDGFß fusion transcripts is not only of diagnostic value but also enables an alternative imatinib-based therapy in inoperable or metastatic cases. The pertinent literature is reviewed.

Mature Cystic Teratoma of the Lung With a Somatic-Like Malignant Component in a Patient With Testicular Germ-Cell Tumor / Teratoma quístico maduro de pulmón con componente maligno de tipo somático en un paciente con un tumor testicular de células germinales

No disponible

[Nested variant Transitional Cell Carcinoma. Report of two cases and bibliographic review.] / El carcinoma urotelial variante en nidos(NESTED). Presentación de dos casos y revisión de la literatura.

OBJECTIVE: Nested type transitional cell carcinoma of the bladder is a rare histological variant among bladder tumors. Although clinical presentation is similar to the other bladder tumors, its macroscopic appearance may be equivocally benign, with submucosal growing which is difficult to detect on cystoscopy, so that diagnosis may be delayed. METHODS: We present the characteristics of nested type transitional cell carcinoma and review the differential diagnosis for this entity with possible counterfeiters. RESULTS: In this article, we report two cases of nested type transitional cell carcinoma that presents, in one of them, all three growing patterns. CONCLUSIONS: Microscopically nested transitional cell carcinoma is characterized by a cell distribution forming nests and tubules. They generally present low cytologic atypia simulating a low grade urothelial carcinoma, or benign bladder lesions such as von Brunn nests or nefrogenic adenoma.

El carcinoma urotelial variante en nidos (NESTED). Presentación de dos casos y revisión de la literatura / Nested variant Transitional Cell Carcinoma. Report of two cases and bibliographic review

OBJETIVO: El carcinoma urotelial de vejiga tipo "nested" o en nidos es una variante histológica rara dentro de los tumores uroteliales de vejiga. Aunque las manifestaciones clínicas son semejantes a los demás tumores de vejiga, su apariencia macroscópica puede ser equívocamente benigna, con crecimiento submucoso difícil de detectar en la cistoscopia, lo que puede retrasar el diagnóstico. MÉTODO: presentamos las características del carcinoma urotelial variante tipo nested y revisamos los diagnósticos diferenciales de esta entidad con sus posibles imitadores. RESULTADO: En este trabajo presentamos dos casos de carcinoma urotelial tipo nested que presentan, en uno de los casos, los tres patrones de crecimiento. CONCLUSIONES: Microscópicamente el carcinoma urotelial nested se caracteriza por la distribución celular en forma de nidos y túbulos. Generalmente presentan poca atipia citológica que simula un carcinoma urotelial de bajo grado, o lesiones vesicales benignas como los nidos de von Brunn o los adenomas nefrogénicos

OBJECTIVE: Nested type transitional cell carcinoma of the bladder is a rare histological variant among bladder tumors. Although clinical presentation is similar to the other bladder tumors, its macroscopic appearance may be equivocally benign, with submucosal growing which is difficult to detect on cystoscopy, so that diagnosis may be delayed. METHODS: We present the characteristics of nested type transitional cell carcinoma and review the differential diagnosis for this entity with possible counterfeiters. RESULTS: In this article, we report two cases of nested type transitional cell carcinoma that presents, in one of them, all three growing patterns. CONCLUSIONS: Microscopically nested transitional cell carcinoma is characterized by a cell distribution forming nests and tubules. They generally present low cytologic atypia simulating a low grade urothelial carcinoma, or benign bladder lesions such as von Brunn nests or nefrogenic adenoma

[Small cell bladder carcinoma in age extremes: Report of two cases.] / Carcinoma de célula pequeña de vejiga urinaria en edades extremas: presentación de dos casos.

OBJECTIVE: We report 2 cases of small cell neuroendocrine carcinomas (CCP) of the urinary bladder in patients aged 37 and 80 years. CCP is a malignancy with poor prognosis. We review the literature, under the current WHO classification (2016). METHODS: Paraffin blocks were cut for HE staining and immunohistochemistry to analyze the expression of neuroendocrine differentiation. RESULTS: The main diagnosis was based on histopathologic features, which revealed a diffuse growth pattern of small cells with scant cytoplasm and hyperchromatic nuclei. The result of the additional technical immunoreaction was positive for synaptophysin and CD56. CONCLUSIONS: Our cases have been reviewed with the literature to discuss the evolution and differential diagnosis of small cell carcinoma of the urinary bladder. This is a rare tumor with very aggressive behavior and its diagnosis lies in its morphology, and immunohistochemical profile.

Carcinoma de célula pequeña de vejiga urinaria en edades extremas: presentación de dos casos / Small cell bladder carcinoma in age extremes: Report of two cases

Objetivo: Exponemos 2 casos de carcinomas neuroendocrinos célula pequeña (CCP) de vejiga urinaria en pacientes de 37 y 80 años. CCP es una neoplasia maligna de pronóstico infausto y en este trabajo, realizamos una revisión de la literatura, bajo la clasificación actual de la OMS de 2016. Métodos: Se han realizado cortes de bloques de parafina para tinción con HE y para técnicas inmunohistoquímicas con el fin de analizar la expresión de diferenciación neuroendocrina. Resultados: El diagnóstico principal se basó en las características histopatológicas, observándose un patrón de crecimiento difuso de células pequeñas con escaso citoplasma y núcleo hipercromático. El resultado de las técnicas complementarias reveló inmunorreacción positiva para sinaptofisina y CD56. Conclusiones: Nuestros casos han sido revisados junto con la literatura para discutir la evolución y el diagnóstico diferencial del carcinoma de célula pequeña de vejiga urinaria. Este es un tumor poco frecuente, de comportamiento muy agresivo y su diagnóstico reside en su morfología y perfil inmunohistoquímico (AU)

Objective: We report 2 cases of small cell neuroendocrine carcinomas (CCP) of the urinary bladder in patients aged 37 and 80 years. CCP is a malignancy with poor prognosis. We review the literature, under the current WHO classification (2016). Méthods: Paraffin blocks were cut for HE staining and immunohistochemistry to analyze the expression of neuroendocrine differentiation. Results: The main diagnosis was based on histopathologic features, which revealed a diffuse growth pattern of small cells with scant cytoplasm and hyperchromatic nuclei. The result of the additional technical immunoreaction was positive for synaptophysin and CD56. Conclusions: Our cases have been reviewed with the literature to discuss the evolution and differential diagnosis of small cell carcinoma of the urinary bladder. This is a rare tumor with very aggressive behavior and its diagnosis lies in its morphology, and immunohistochemical profile (AU)

[Adenoma metanephric: Report of 2 cases and bibliographic review.] / Adenoma metanefrico: presentación de 2 casos y revisión de la literatura.

OBJECTIVE: Two cases of metanephric adenoma are presented, a rare benign renal tumor, and a literature review is done under the current WHO classification (2016). METHODS: Standard histopathological study was performed with hematoxylin-eosin and immunohistochemistry to analyze the expression of WT, Vimentin, Racemase, CK7, CD10 and RCC. RESULTS: Neoplasms of 3 and 4.5 cm, histologically, exhibiting tubulopapillary architecture. There was no evidence of significant nuclear atypia and mitotic figures. Immunohistochemical study showed positive immunoreaction for WT1 and Vimentin in tumor cells. CONCLUSIONS: Two new cases of metanephric adenoma are presented and a review of the literature was performed in order to discuss the prognosis and differential diagnosis of metanephric adenoma. This is a rare tumor and its diagnosis lies on its morphology and its immunohistochemical profile.

Adenoma metanefrico: presentación de 2 casos y revisión de la literatura / Adenoma metanephric: Report of 2 cases and bibliographic review

OBJETIVO: Presentamos 2 casos de adenoma metanéfrico, un tumor renal benigno poco frecuente y realizamos una revisión de la literatura bajo la clasificación actual de la OMS (2016). MÉTODOS: Se realizaron cortes de bloques de parafina para tinción con HE y técnicas inmunohistoquímicas para analizar la expresión de WT, Vimentina, Racemasa, CK7, CD10 y RCC. RESULTADOS: Las neoplasias de 3 y 4,5 cm, histológicamente mostraban arquitectura tubular y papilar. No se evidenció atipia nuclear significativa ni figuras de mitosis. El estudio inmunohistoquímico demostró inmunorreacción positiva de las células tumorales para WT1 y Vimentina. CONCLUSIONES: Presentamos 2 nuevos casos de adenoma metanéfrico y realizamos revisión de la literatura que hay al respecto para discutir la evolución y el diagnóstico diferencial del adenoma metanéfrico. Este es un tumor poco frecuente y su diagnóstico reside en su morfología y perfil inmunohistoquímico

OBJECTIVE: Two cases of metanephric adenoma are presented, a rare benign renal tumor, and a literature review is done under the current WHO classification (2016). METHODS: Standard histopathological study was performed with hematoxylin-eosin and immunohistochemistry to analyze the expression of WT, Vimentin, Racemase, CK7, CD10 and RCC. RESULTS: Neoplasms of 3 and 4.5 cm, histologically, exhibiting tubulopapillary architecture. There was no evidence of significant nuclear atypia and mitotic figures. Immunohistochemical study showed positive immunoreaction for WT1 and Vimentin in tumor cells.CONCLUSIONS: Two new cases of metanephric adenoma are presented and a review of the literature was performed in order to discuss the prognosis and differential diagnosis of metanephric adenoma. This is a rare tumor and its diagnosis lies on its morphology and its immunohistochemical profile

Expression of dog1 in low-grade fibromyxoid sarcoma: A study of 19 cases and review of the literature.

DOG1 is a highly-sensitive marker often included in the immunohistochemical panel for the diagnosis of gastrointestinal stromal tumors (GISTs). Recent research has shown that DOG1 may also be expressed by low-grade fibromyxoid sarcomas (LGFMSs); this may give rise to diagnostic error when the sarcoma is located in the abdominal cavity. This paper reports on immnohistochemical expression of DOG1 in 19 LGFMSs using two different monoclonal antibodies: K9 (Leica, Novocastra Laboratories, Newcastle upon Tyne, UK) and SP31 (Thermo Scientific, Freemont, USA). All LGFMSs displayed the standard histological pattern of alternating myxoid and fibrous areas, low cellularity and bland spindle-cell morphology. Positive staining for MUC4 was observed in 18/19 cases (94.7%), while there was rearrangement of the FUS gene in 14/19 (73.7%) cases and of the EWR1 gene in 2/19 (10.5%). The sarcoma staining negative for MUC4 displayed FUS gene rearrangement. Whole-section immunohistochemistry revealed positive staining for DOG1 in 8/19 cases (42.1%), though only with clone K9. Cytoplasmic as well as membrane staining was observed in all cases; staining was focal (10-30%) and of varying intensity (1+ to 2+). In conclusion, DOG1 clone K9 exhibited low sensitivity (42.1%) for the diagnosis of LGFMS, although higher than clone SP31. Since the two clones display similar sensitivity and specificity for GIST diagnosis, SP31 would appear to be more specific for this purpose, since no reaction was observed here with LGFMS, a GIST-mimicking lesion.

Complicaciones de la enfermedad renal quística adquirida: síndrome de Wünderlich y carcinoma papilar / Major compications of acquired renal cystic disease: Wünderlich syndrome and papilar carcinoma

OBJECTIVO: Presentamos el caso de un paciente con enfermedad renal quística adquirida en hemodiálisis por enfermedad renal terminal que desarrolló dos de las complicaciones más graves asociadas a esta entidad; un carcinoma renal y hemorragia renal espontánea. MÉTODOS: Nuestro caso se trata de un paciente con enfermedad renal quística adquirida (ERQA), monorreno e intervenido por carcinoma renal de células claras 4 años antes, que desarrolló un síndrome de Wünderlich (SW). RESULTADOS: En el estudio anatomopatológico de la pieza de nefrectomía se objetivó un carcinoma renal papilar en el contexto de un riñón poliquístico tras intervención de urgencia por SW. CONCLUSIONES: La hemorragia renal es una complicación grave de la ERQA. Los pacientes sometidos a diálisis deben ser vigilados de forma activa por el riesgo de desarrollar ERQA y las complicaciones asociadas

OBJECTIVE: We report a case of acquired renal cystic disease associated with renal dialysis and end-stage renal disease. The patient suffered the two major complications related with acquired renal cystic disease; hemorrhage and renal carcinoma. METHODS: Our case is a patient with acquired renal cystic disease, single kidney after surgery for renal clear cell carcinoma four years earlier, who developed a Wünderlich syndrome (WS). RESULTS: The histological study of the nephrectomy specimen showed a renal papillary carcinoma in the context of acquired renal cystic disease after surgery for a WS. CONCLUSIONS: Renal hemorrhage is a serious complication that can lead to a fatal outcome. Patients undergoing dialysis should be monitored actively due to the risk of developing acquired renal cystic disease and associated complications