Neuroendocrine Tumor Metastases to the Breast: A Case Report and Review of the Literature.

Breast metastases from neuroendocrine neoplasms (NENs) are considered infrequent. We report a case of a patient with ileocecal neuroendocrine tumor (NET) metastases to both breasts, for whom the initial clinical presentation was chronic diarrhea. Breast metastasis was initially suspected by a 68-Gallium DOTANOC positron emission tomography (PET)/CT and was confirmed by histopathology. We also performed a literature review in which we identified 116 cases of NENs metastatic to the breast reported so far. Most cases occurred in older women, were caused by NETs, and had the gastrointestinal tract as the primary site.

Transoral robotic resection of unusual spindle cell/pleomorphic lipoma of the larynx.

Spindle cell/pleomorphic lipoma (SC/PL) is a subcutaneous mass usually localised on nape, shoulder or upper back. It is a benign lipogenic tumour composed of primitive CD34-positive spindle cells, floret-like multinucleated giant cells and mature adipocytes. Complete surgical excision is the optimal treatment. This unusual tumour in the larynx has only been reported in the medical literature once and was treated surgically by open approach. Actually, transoral robotic surgery (TORS) is most suitable because provides tridimensional magnified view plus a greater mobility with instruments, allowing complete and safe removal of the supraglottic mass, allowing rapid healing and recovery. We present the first case of a SC/PL of larynx managed with TORS. Four hours after surgery, the patient was able to take a soft diet and was discharged 2 h later. The follow-up showed an excellent clinical and functional outcome.

Advantages of the 99mTc-sestamibi Single-Photon Emission Computed Tomography/Computed Tomography in Occult Parathyroid Adenoma and Concomitant Thyroid Papillary Carcinoma.

Hyperparathyroidism and concurrent thyroid nodular disease are prominent. In contrast, concomitant papillary thyroid cancer and hyperparathyroidism are uncommon (1%-2%). Parathyroid adenomas in unusual locations are difficult to detect by conventional diagnostic imaging. 99mTc-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) has increased the localizing success rate of these lesions since it provides specific functional and anatomical information, improving exploratory parathyroid surgery planning and decreasing operative time, unnecessary dissections, complications, and morbidity. We confirmed its usefulness in a patient with an occult parathyroid adenoma that was clearly identified by 99mTc-sestamibi SPECT/CT 2 weeks after a thyroidectomy for papillary carcinoma. The SPECT/CT results allowed us to successfully perform efficient reexploration of the thyroid bed, in a retroesophageal parathyroid adenoma by minimally invasive surgery.

«Tumor to tumor metástasis». Un evento poco frecuente. A propósito de un carcinoma renal metastásico a un carcinoma papilar de tiroides / 'Tumour to tumour metastasis': A rare event. Case report of a metastasic renal carcinoma in a papillary carcinoma of the thyroid

La presencia de un tumor metastásico a otro tumor es un evento poco frecuente denominado como «tumor to tumor metástasis». Uno de los principales tumores receptores es el carcinoma renal de células claras (CRCC), y de hecho se conoce que afecta a la glándula tiroides; sin embargo, la coexistencia de un tumor primario de glándula tiroides con metástasis de un CRCC es un hallazgo poco frecuente. Nosotros presentamos el que podría corresponder al cuarto caso reportado en la literatura de un CRCC asociado a un carcinoma papilar de tiroides. Se revisa adicionalmente los casos previamente publicados (AU)

The presence of metastatic tumour in another tumour is an infrequent event called tumor-to-tumor metastasis. One of the main recipients tumours is renal clear cell carcinoma (RCCC) which is known to affect the thyroid gland; however, RCCC metastases in a primary tumour of the thyroid are rare. We present a case of RCCC associated with a papillary thyroid carcinoma which is, to our knowledge, only the fourth reported case to date. In addition we review the previously published cases (AU)

Diferencias y controversias entre el reporte de patología y la interpretación clínica en patología tiroidea. I parte: Factores pronósticos / Thyroid pathology: differences and controversies between the pathology report and clinical interpretation. Part I: prognostic factors

Resumen El cáncer de la glándula tiroides es una neoplasia cuya detección, diagnóstico y tratamiento se realiza de manera interdisciplinaria, por lo tanto el diagnóstico definitivo histopatológico debe ser completo y claro; de modo que pueda ser interpretado de la misma manera por parte del grupo médico tratante. De manera frecuente, los médicos no patólogos que reciben el reporte de un estudio histopatológico de tiroides se enfrentan con dificultades al momento de interpretar el reporte histopatológico y，por lo tanto, en definir la posterior conducta médica. El objetivo de este primer artículo es revisar de manera breve algunos de los diferentes temas que más generan dudas en la interpretación del reporte histopatológico y de las técnicas diagnósticas usadas en patología por parte de los médicos tratantes que tienen un impacto en las decisiones clínicas originadas a partir de la clasificación, estadificación, pronóstico y seguimiento de la enfermedad.

Abstract Cancer of the thyroid gland is a neoplasia for which its detection, diagnosis and treatment is interdisciplinary. For this reason, the definitive diagnosis by histopathology should be complete and clear so that it can be interpreted in the same way by the treating medical group. Non-pathology physicians who receive the report of a histopathological study of the thyroid often have difficulties when interpreting the report and therefore in defining the subsequent medical behaviour. The objective of this first article is to review briefly some of the different subjects that generate most doubts in the interpretation of the histopathology report, and the diagnostic techniques used in pathology by the attending physicians that have an impact on clinical decisions arising from the classification, staging, prognosis, and follow-up of the disease.

Gliomas tipo astrocytoma pilocítico "atípico recurrente" y gen B-RAF: presentación de caso clínico, discusión / Glioma type pilocytic astrocytoma "atypical recurrent" and gen BRAF: Clinical case presentation, discussion

RESUMEN El astrocitoma pilocítico (AP) es una neoplasia bien diferenciada, grado I OMS,que predomina en la infancia y es raro en la población adulta. Se reportan casos atípicos con una biología tumoral agresiva que continúan preservando la histología benigna o se transforman hacia gliomas de alto grado. Algunos estudios genéticos en esté subtipo de tumor referencian la activación de la vía MAPK/ERK a través de cambios en el gen BRAF. El objetivo del grupo es presentar un caso clínico representativo de un AP con evolución "atípica" y realizar una revisión actualizada desde la biología, genética, las posibilidades terapéuticas emergentes y exponer las controversias del tratamiento desde lo quirúrgico y las terapias complementarias.

SUMMARY The pilocytic astrocytoma (PA), formerly referred to as juvenile pilocytic astrocytomas, are WHO grade I tumors, that commonly occur during childhood and rarely in the adult population. Genetic studies of this tumor report an activation of the MAPK / ERK pathway through changes in the BRAF gene. The aim of this article is to report a series of atypical PA cases with an aggressive tumor biology that continue preserving the benign histology or transformed into high-grade gliomas, and review the biology, genetics, and emerging therapeutic possibilities for these cases. And finally expose controversies from the surgical treatment and complementary therapies.

Linfoma leptomeníngeo primario. Reporte de tres casos y revisión de la literatura / Primary leptomeningeal lymphoma. Report of three cases and review of the literature

El linfoma leptomeníngeo primario (LLMP) es una entidad con baja frecuencia de presentación, representa del 1% al 2,4% de los linfomas primarios del sistema nervioso central; las variedades histológica más observadas son el linfoma de la zona marginal tipo MALT, el linfoma B de célula grande difuso y el linfoma linfoblástico de células B. La localización y su extensión determinan las manifestaciones clínicas; en radiología se prefieren las imágenes con medios de contraste, ya que tienden a confundirse con meningiomas como la primera impresión diagnóstica y son la cirugía y los estudios de patología los que confirman el diagnóstico. La quimioterapia es la base del tratamiento en esta entidad, la radioterapia se deja como una opción secundaria. El propósito de este trabajo es presentar tres casos clínicos representativos de LLMP y las variantes por imágenes de radiología, la revisión enfocada de la literatura y el tratamiento de esta infrecuente patología.

Primary Leptomeningeal lymphmoma (PLML) is a low frequency neoplasm representing 1% to 2,4% of primary lymphomas of the central nervous system (CNS). The most frequent histological variety is the extranodal marginal zone lymphoma (MALT lymphoma), but other variants are reported such as diffuse large cell B-cell lymphoma (DLBCL). The location and extent determine the clinical manifestations. In radiology, images with contrast are preferred to difference from meningiomas which are the main differential diagnosis; nevertheless surgery and histology confirm the diagnosis. Chemotherapy is the mainstay of treatment and radiation therapy is a secondary alternative. The purpose of this paper is to present three cases of PML, the radiological variants and to conduct a focused literature review with treatment of this pathology.

Carcinoma anficrino de glándula mamaria. Reporte de un caso inusual / Breast amphicrine carcinoma. Report of an unusual case

Los tumores anficrinos de la glándula mamaria son lesiones duales muy poco frecuentes con diferenciación epitelial y neuroendocrina de una misma célula. Nosotros presentamos el caso de una mujer con masa en el seno derecho. El estudio histopatológico mostró un tumor maligno constituido por células pequeñas entremezcladas con algunas células con aspecto en anillo de sello. El uso de anticuerpos monoclonales mostró inmunoreactividad para marcadores epiteliales y neuroendocrinos en las células malignas. Estas características permitieron hacer el diagnóstico de un tumor anficrino basado en la expresión en la misma célula de marcadores epiteliales y neuroendocrinos. El diagnóstico diferencial debe realizarse con los tumores de colisión o con metástasis. La interpretación rigurosa de la inmunohistoquímica en las células neoplásicas en un tumor anficrino es útil para distinguir esta entidad de otras patológicas con características morfológicas similares.

Amphicrine tumours of the mammary gland are very rare dual lesions with epithelial and neuroendocrine differentiation in the same cell. We report the case of a woman with a mass in the right breast. The histopathology study showed a malignant tumour formed by small cells inter-mixed with some cells with a signet ring appearance. The use of antibodies showed immunoreactivity for epithelial and neuroendocrine markers in the malignant cells. These characteristics enable the diagnosis of an amphicrine tumour, based on the expression of epithelial and neuroendocrine markers in the same cell. The differential diagnosis must be made with collision tumours or with metastasis. The rigorous interpretation of the immunohistochemistry in the malignant cells in an amphicrine tumour is useful in order to distinguish this tumour from other diseases with similar morphological characteristics.

Expresión de marcadores hipóxicos y glucolíticos CAIX, GLUT-1, HKII y su relación con la respuesta temprana al tratamiento en carcinoma escamocelular de cuello uterino / Expression of the hypoxic and glycolytic markers, CAIX, GLUT-1 and HKII and their association with early treatment response in squamous cell carcinomas of the uterine cervix

Objetivo. Determinar la expresión de CAIX, GLUT-1, HKII y establecer si existe asociación entre la expresión y la respuesta temprana al tratamiento en carcinomas escamocelulares de cuello uterino. Sujetos y métodos. En este estudio de tipo cohorte retrospectiva se incluyó a 66 pacientes en estadios FIGO IIB y IIIB durante el periodo del 2001 al 2007, con una edad promedio de 47 años. De las 66 pacientes, 22 fueron tratadas con radioterapia exclusiva y 44 con quimioterapia concomitante a radioterapia. La expresión de las proteínas CAIX, GLUT-1 y HKII fue determinada mediante inmunohistoquímica en biopsias tomadas antes del tratamiento. Resultados. Se encontró un mayor incremento en la expresión de GLUT-1 (74%), seguido de CAIX (41%) y HKII (18%). La coexpresión de GLUT-1 y CAIX resultó ser significativa (p < 0,002) en comparación con GLUT-1 y HKII. Además, se observó una tendencia de riesgo de no respuesta cuando se expresan simultáneamente las 3 proteínas. Conclusiones. El incremento en la expresión de GLUT-1 respecto de CAIX y HKII reafirma el concepto de que los carcinomas tienen un alto consumo de glucosa y su coexpresión con CAIX y HKII como factores biológicos preexistentes puede contribuir a esclarecer los mecanismos de hipoxia en la invasión tumoral, así como su posible efecto frente a tratamientos como la radioterapia exclusiva y la radioquimioterapia concomitante para el manejo de cáncer de cuello uterino en estadios ii B y iii B (AU)

Objective: To determine the expression of CAIX, GLUT-1 and HKII and whether there is an association between expression of these markers and early treatment response in squamous cell carcinomas of the uterine cervix. Subjects and methods: This retrospective cohort study included 66 patients with squamous cell carcinomas of the uterine cervix in FIGO (International Federation of Gynecology and Obstetrics) stages IIB and IIIB between 2001 and 2007. The mean age was 47 years. Of the 66 patients, 22 were treated with radiotherapy and 44 with concurrent radiochemotherapy. Expression of the proteins CAIX, GLUT-1 and HKII was determined by immunohistochemistry in biopsies taken before treatment. Results: The highest increase was found in expression of GLUT-1 (74%), followed by that of CAIX (41%) and HKII (18%). Coexpression of GLUT-1 and CAIX was significant (p <0.002) compared with that of GLUT-1 and HKII. When all three proteins were expressed simultaneously, we observed a tendency toward lack of treatment response. Conclusions: Increased expression of GLUT-1 compared with that of CAIX and HKII supports the notion that carcinomas have high glucose consumption. Coexpression of GLUT-1 with CAIX and HKII as preexisting biological factors could help to elucidate the mechanisms of hypoxia in tumoral invasion. Coexpression could also help to explain the possible effect of these markers on response to treatments such as exclusive radiotherapy and concurrent radiochemotherapy in the management of stage IIB and IIIB cervical cancer (AU)

Tumor del estroma gastrointestinal gástrico con metástasis inusual al cráneo / Gastric gastrointestinal stromal tumor with unusual skull metastasis

Los tumores del estroma gastrointestinal GIST, se originan en la pared del tracto digestivo desde el esófago al ano. Aproximadamente 25% de los GIST gástricos son clínicamente malignos y desarrollan metástasis principalmente al hígado, menos comúnmente a tejidos blandos y hueso. Se presenta el caso de un paciente con GIST gástrico y metástasis al hígado e inusualmente al cráneo.

Gastrointestinal stromal tumors (GISTs) originate in the wall of the digestive tract from the esophagus to the anus. Approximately 25% of gastric GISTs are clinically malignant. Most often they metastasize to the liver, less commonly to soft tissues and bone. The clinical case of a patient with a gastric GIST, liver and unusual cranial metastasis is presented.

Spindle cell oncocytoma of the adenohypophysis.

Spindle cell oncocytoma of the adenohypophysis (SCO) is defined as spindle to epithelioid cells with oncocytic appearance presenting in the adenohypophysis. In contrast to pituitary adenomas, the SCO does not show immunoreactivity for neuroendocrine markers and pituitary hormones but co-expressed vimentin, S-100 protein, epithelial membrane antigen (EMA), and antimitochondrial antibody MU213-UC clone 131-1. We describe an SCO in an adult, a 42-year-old woman whose magnetic resonance (MR) images documented an intrasellar lesion located in the hypophysis. Histopathological examination showed a tumor composed predominantly of spindle cells. Immunohistochemical studies showed positivity for vimentin, S10, EMA, and antimitochondrial antibody MU213-UC clone 131. Cytokeratin (CK) (AE1/AE3), glial fibrillary acidic protein (GFAP), chromogranin, synaptophysin, PGP9.5, CD57, desmin, D2-40, smooth muscle actin (SMA), Bcl-2, progesterone receptor, and CD34 were negative. Neuropeptides were negative. With electron microscopy, the neoplastic cells appear filled with mitochondria, well-formed desmosomes, but lacked secretory granules. SPO is a rare non-endocrine neoplasm of the adenohypophysis with benign biological behavior corresponding to WHO grade I.

Metástasis selar y al seno cavernoso, de un carcinoma de células de Merkel: reporte de un caso / Sellar and cavernous sinus metastasis from a Merkel cell carcinoma: case report and literature review

El carcinoma de células de Merkel es un tumor maligno y muy raro de la piel. Este tumor emerge de las células epiteliales que presentan una diferenciación neuroendocrina. Ocurre más comúnmente en los adultos masculinos mayores. Las metástasis intracraneales de un carcinoma de células de Merkel son aun más raras. En este articulo, se presentara un caso de un paciente masculino de 70 años con antecedente de carcinoma de células de Merkel quien debuto con una ptosis que progresivamente presento una parálisis completa del tercer par craneal. En los estudios realizados al paciente, se encontró una lesión infiltrante al seno cavernoso y a la silla turca que resulto ser una metástasis por un carcinoma de células de Merkel. En esta publicación, se discutirá el caso clínico y se revisará la literatura al respecto de estas lesiones raras del sistema nervioso central.

Merkel cell carcinoma is a rare and malignant tumor of the skin. This lesion arises from epithelial cells that have undergone neuroendocrine differentiation. They are more commonly found in older male adults. Intracranial metastases from Markel cell carcinoma are even rarer. We will present a case of a 70 year old male with known history of Merkel cell carcinoma that suddenly presented with a right eye ptosis and progressively presented complete third nerve palsy. The patient was studied and was found to have an infiltrating lesion of the cavernous sinus and the sellar region. This tumor resulted in a metastasis from a Merkel Cell Carcinoma. In this article we will discuss the clinical case of this patient and we will review the literature concerning this rare lesion of the Central nervous system.

Condrosarcoma lrríngeo: una patología poco usual / Laryngeal chondrosarcoma: a very unusual pathology

El condrosarcoma es el tercer tumor más frecuente de los huesos, luego del mieloma y el osteosarcoma, y constituye aproximadamente el 20% de todos los tumores óseos malignos. Generalmente se localiza en los huesos largos y de la pelvis y tan sólo 2 a 5% se ubican en la cabeza y el cuello, principalmente en el maxilar. Los síntomas iniciales suelen ser muy bizarros y en ocasiones sólo la sensación de masa del cuello hace que el paciente acuda al médico. Por la íntima relación de la laringe y de la glándula tiroides, este tumor puede llevar a una falsa impresión diagnóstica. Como ocurrió en este caso, una paciente que consultó por masa del nivel VI (zona central del cuello), con ecografía de nódulo tiroideo y aspiración con aguja fina (ACAF) positiva para un bocio tiroideo. En la TAC por infiltración del cricoides se sospechó la presencia de un carcinoma tiroideo invasivo, y sólo hasta la intervención quirúrgica en orientación con la biopsia por congelación intraoperatoria y el estudio definitivo de patología se realizó el diagnóstico de condrosarcoma bien diferenciado (Grado 1). Como es un caso de difícil diagnóstico y una patología muy infrecuente se reportó y se revisó el tema.

Chondrosarcoma is the third most frequently occurring bone tumor, following myeloma and osteosarcoma; it accounts for around 20% of all malign bone tumors. They are usually localized in the long bones and the bones of the pelvis; only 2% to 5% are located in the head and neck, mainly in the maxillary bone. Initial symptoms are usually very bizarre and sometimes only a sensation of having a neck mass means that a patient goes to see a doctor. Due to the larynx's intimate relationship with the thyroid gland, this tumor may give a false diagnostic impression. As happened in this case, a patient consulted due to level 4 mass (central neck area), echography of the thyroid nodule and fine needle aspiration (FNA) having proved positive for thyroid goiter. The presence of an invasive thyroid carcinoma was suspected in the TAC due to infiltration of the cricoid cartilage; a well-differentiated diagnosis of chondrosarcoma (grade 1) was only made during surgical intervention orientated by biopsy following intraoperation exposure and the definitive study of the pathology. This case has been reported and the topic reviewed as it was difficult case to diagnose and involved a very infrequently occurring pathology.

Neoplasias primarias y secundarias múltiples, el sistema nervioso: una parte del todo / Primary and secondary multiple neoplasms of central nervous system: o part of everything: what´s new in this genetics

Los tumores primarios y secundarios múltiples se han descrito desde finales del siglo XIX, sin embargo los criterios específicos para definirlo como una entidad claramente reconocida solo se precisaron hasta 1932. El desarrollo de un segundo tumor maligno después del tratamiento del primero con radioterapia o quimioterapia no es un evento infrecuente sobre todo en pacientes de edad pediátrica, en especial en las neoplasias hematolinfoides. Factores como la edad, las alteraciones genéticas, el tipo de tumor primario, la exposición a determinadas sustancias o pató-genos, la herencia o inclusive el estado inmunológico de un paciente se han relacionado con el riesgo de tener o presentar tumores múltiples.El cáncer es una enfermedad relacionada con alteraciones en el genoma. Hay reportes de tumores cerebrales en mujeres asociados con cáncer de vejiga, colo-rectal, seno y endometrio y en los hombres una alta incidencia de linfoma de SNC (sistema nervioso central) como una neoplasia maligna secundaria. La secuenciación completa del genoma humano y el continuo perfeccionamiento de las tecnologías hacen posible visualizar para tiempos cercanos una mejor comprensión de los cambios en el genoma y su causalidad con el cáncer. El propósito de este artículo es presentar un caso clínico muy representativo y una revisión de algunos avances en el campo de la genética, en este interesante campo.

The description of patients with multiple primary and secondary tumors is an event reported since the late nineteenthcentury, however the specific criteria to define it as an entity were not published until 1932. The development of a second malignancy after treatment of the first with radiotherapy or chemotherapy is not uncommon, especially in pediatric patients, however, factors such as age, genetic alterations, primary tumor type, exposure to certain substances or pathogens, genetics and patient’s immune status have influence in the presence of multiple tumors. Cancer is a disease related to alterations in the genome. There are reports of brain tumors in women associated with bladdercancer, colorectal and endometrial cancer and in men a high incidence of lymphoma of CNS (central nervous system) as a secondary malignancy. The complete sequencing of human genome and the continuous improvement of technologies will allow for a better understanding of changes in the genome and its causality with cancer. The our purpose is present to the readers a review of the literature with the progress in the field of genetics, and alsoreport a representative clinical case.

Primary malignant solitary fibrous tumor/hemangiopericytoma of the parotid gland / Tumor fibroso solitario maligno primario/hemangiopericitoma de la glándula parótida

Solitary fibrous tumor (SFT) was first described in the pleura by Lietaud in 1767; later in 1870, Wagner described the localized nature of this type of tumor and Klemperer and Rabin classified pleural tumors into two types: diffuse mesotheliomas and localized mesotheliomas. Recent years have seen the redefinition of this neoplasm, due to better technology; it is now proven that this neoplasm may have multiple different extrapleural origins including the head and neck regions. This diversity of locations is related to the particular mesenchymal histogenesis of SFT which allows its development from very unusual sites such as the salivary glands (SGs). In this particular site, this neoplasm is very infrequent and most of reported cases refer to benign disease, with just one case informed so far of primary malignant SFT (AU)

El tumor fibroso solitario (TFS) fue primeramente descrito en la pleura por Lietaud en 1767; posteriormente en 1870, Wagner describió la naturaleza localizada de este tipo de tumor y Klemperer y Rabin, en 1931, clasificaron los tumores pleurales en dos tipos: mesoteliomas difusos y mesoteliomas localizados. En los últimos años se ha redefinido esta neoplasia, debido a la mejora de las tecnologías; ahora se ha probado que puede tener múltiples y diferentes orígenes extra-pleurales, incluyendo la región de cabeza y cuello. Esta diversidad de localizaciones se relaciona con la histogénesis mesenquimal particular del TFS, que permite su desarrollo desde localizaciones muy inusuales tales como las glándulas salivares (GS). En esta localización particular este tumor es muy infrecuente, y muchos casos reportados se refieren a una enfermedad benigna, con un único caso informado hasta la fecha de TFS maligno primario (AU)

[Primary malignant solitary fibrous tumor/hemangiopericytoma of the parotid gland]. / Tumor fibroso solitario maligno primario/hemangiopericitoma de la glándula parótida

Solitary fibrous tumor (SFT) was first described in the pleura by Lietaud in 1767; later in 1870, Wagner described the localized nature of this type of tumor and Klemperer and Rabin classified pleural tumors into two types: diffuse mesotheliomas and localized mesotheliomas. Recent years have seen the redefinition of this neoplasm, due to better technology; it is now proven that this neoplasm may have multiple different extrapleural origins including the head and neck regions. This diversity of locations is related to the particular mesenchymal histogenesis of SFT which allows its development from very unusual sites such as the salivary glands (SGs). In this particular site, this neoplasm is very infrequent and most of reported cases refer to benign disease, with just one case informed so far of primary malignant SFT.

Primary yolk sac tumor of the urachus.

INTRODUCTION: Neoplasms originating from the urachus are rare. The most common urachal malignancy is adenocarcinoma, whereas extragonadal germ cell tumors, primarily of the urachus, are an extremely rare finding. OBJECTIVE: To describe a primary yolk sac tumor (YST) of the urachus in an adult. CASE REPORT: A 44-year-old woman presented with 6 months of pelvic pain associated with a sensation of progressive mass growth. At the time of tumor resection, the tumor was found to be attached by a pedicle to the dome of the bladder, with no injury to the adjacent organs. Pathological study showed a neoplasm with epithelioid cells, pseudocysts, a myxomatous background, and Schiller-Duval body formations. Immunohistochemistry stains showed positivity to AE1/AE3, α-1-fetoprotein, and α-1-antitrypsin and negativity to other markers. CONCLUSION: An unusual case of a YST in the urachus is presented. This is the first reported adult case based on the authors' bibliographic search.

Neurotequeoma (mixoma de la vaina neural) celular atípico del pie / Atypical cellular neurothekeoma (nerve sheath myxoma) of the foot. A case report

Introducción. Los neurotequeomas o mixomas de la vaina neural son tumores benignos poco frecuentes, derivados de la vaina de los nervios periféricos, que suelen alojarse en la dermis y en el tejido subcutáneo de la cabeza, el cuello, las extremidades superiores de adultos jóvenes, raramente observados en los miembros inferiores. Objetivo. Se presenta un caso de neurotequeoma celular atípico localizado en el pie de un niño. Caso clínico. Niño de 10 años, que presento nódulo bien circunscrito en dorso de pie derecho de 0,6×0,5cm de diámetro, de 3 años de evolución. Fue resecado realizando el diagnóstico de neurotequeoma celular atípico del pie. Conclusión. Los neurotequeomas son lesiones poco frecuentes, descritas recientemente, de la cual se han descrito algunos casos localizados en el pie. Se han descrito 3 variedades de probable diferente origen, lo que explicaría sus características morfológicas e inmunohistoquímicas particulares. Las características de atipia están en relación con hallazgos morfológicos pero carecen de significado clínico en relación con el comportamiento. Estos tumores pueden confundirse fácilmente con una amplia gama de lesiones tumorales, que pueden excluirse gracias a tinciones de inmunohistoquímica(AU)

Introduction. Neurothekeomas, or nerve sheath myxomas, are rare benign tumours, arising from the sheath of peripheral nerves. They are usually found in young adults, in the dermis and subcutaneous tissue of the head, neck and upper limbs and only rarely occur in the lower limbs. Objective. A case of atypical cellular neurothekeoma of the foot in a child is presented. Case report. A 10 year-old child presented with 3 year history of a well circumscribed nodule on the dorsum of the right foot. A 0.6×0.5 nodule was surgically removed and a diagnosis of atypical cellular neurothekeoma was made. Conclusion. Neurothekeomas are a rare new entity, a few cases of which have been described in the foot. Three distinct varieties have been reported, each of which is probably of a different origin, which would explain their morphological features and immunohistochemical findings. The atypia only refers to morphological findings and is not reflected in their clinical behaviour. These tumours can easily be confused with many other lesions and immunohistochemistry is helpful in the differential diagnosis(AU)

Early age renal synovial sarcoma.

OBJECTIVE: We report a primary renal Synovial Sarcoma (SS) case and analyze its features. METHOD: A 15 year old male presented with left abdominal mass and weight loss. CT scan images showed a 13 cm mass located in the lower pole of the left kidney. Renal biopsy recognized an undifferentiated neoplasm, the immunohistochemistry suggesting the probability of neuroectodermic primitive tumor versus SS. Chemotherapy and radical nephrectomy were carried out. Pathological study showed a big multilobulated necrotic tumor 22 x 13 x 12.5 cm. Histopathological study demonstrated a neoplasm composed by immature cells. Currently, patient has survived 1,8 years. A structured bibliographical search was performed in the Medline, Imbiomed and Scielo databases. RESULTS: The final immunohistochemistry studies gave the diagnosis of poorly differentiated renal SS small cell variety. CONCLUSION: The renal SS is extremely infrequent, with less than 40 cases reported, of which this case reports the earlier age. These tumors, when located in the kidney, represent a great diagnostic challenge that requires adequate clinical, radiological, surgical, and pathological correlation for appropriate diagnosis and treatment.