[A 33 year old woman with a six-year history of slight thoracic-abdominal pain]. / Mujer de 33 años de edad con leve dolor toracoabdominal derecho de seis años de evolución, súbitamente agudizado.

We present a case of a benign hybrid nerve sheath tumor showing features of both cellular schwannoma and perineurioma.The patient was a 33 year-old female who presented with a 6 month history of pain in the thorax-lumbar region.Axial CT and MIR images showed and homogeneously enhancing solid oval mass involving the left paravertebra region in contact with the vertebral foramina T9-T11. Morphologically the tumor presented a well formed capsule and showed a uniform highly spindle cell proliferation. The spindle cells were arranged in whorls and intersecting fascicles with focal intervening sclerosis and relatively uniform cellularity with a prominent perivascular lymphocytic infiltrate. No cytological atypia, necrosis or mitoses were present. A second cell component was present composed of spindle-shaped cells with inconspicuous bipolar, pale, eosinophilic cytoplasm with oval nuclei. By immunohistochemistry there was a diffuse staining for S-100, and the elongated bipolar cells were EMA, Glut-1 and Claudin-1. To our knowledge this is the first reported case of a hybrid cellular schwannoma/perineurioma.

Central nervous system atypical teratoid rhabdoid tumor: experience at the National Institute of Pediatrics, Mexico City.

OBJECTIVE: The purpose of this study is to present our experience with ten cases of Central nervous system atypical teratoid rhabdoid tumor (CNS/ATRT). PATIENTS AND METHODS: A series of ten patients with CNS/ATRT, were diagnosed and treated between 1990 and 2005, at the National Institute of Pediatrics, in Mexico City. The gender, age of presentation, clinical features, tumor localization, imaging studies, grade of tumor resection, complications, adjuvant therapy, and survival are presented. RESULTS: The mean age at diagnosis was 37.8 months, seven cases were male, and their average clinical course was 1.3 months. The more common clinical presentation was intracranial hypertension with cranial nerve deficits; location was infratentorial in four patients and supratentorial in six. Hydrocephalus was present as the most common complication (seven cases). In nine patients, the grade of resection was total or subtotal. In one case, it was only possible to perform a biopsy. There were two cases with longer survival (9 and 16 months), and their tumors were resected in total or subtotal manner and received adjuvant therapy (radiotherapy and chemotherapy). CONCLUSIONS: Preliminary results, show that in older children, we can improve their survival with the subtotal or total resection of the tumor and the addition of chemotherapy and radiotherapy.

[Expression of p53 and BCI-2 as prognostic markers and for anatomical location in gastrointestinal stromal tumors (GIST). Clinico-pathological and immunohistochemistry study of 19 cases]. / Expresión de p53 y Bcl-2 como marcadores pronósticos y de localización anatómica en tumores del estroma gastrointestinal. Estudio clínico-patológico e inmunohistoquímico de 19 casos.

OBJECTIVE: To correlate the expression of p53 and BCl-2 with the clinical outcome and anatomic location of the gastrointestinal stromal tumours (GIST). BACKGROUND DATA: The GIST are the most common nonepithelial neoplasm of the gastrointestinal tract. In spite of the existence of a wide range of predictive factors, their clinical outcome is unpredictable. There are several studies that correlate the expression of p53 and Bcl-2 with the clinical outcome and anatomic location of the GIST. METHODS: We obtained 19 cases from the archives of the Department of Pathology of the ABC Medical Center, in Mexico City. GIST were classified into risk groups according to the Fletcher et al. classification. We performed an immunohistochemestry panel including CD117, CD34, actin, desmin, P-S100, p53 and BCl-2 and correlated their expression to the risk group and anatomical site of the tumors. RESULTS: There was less expression of p53 in the gastric tumors (27%) than in small bowel tumors (100%). There was greater expression of p53 in the high-risk tumors than in the very low-risk ones, regardless of the anatomical site. Bcl-2 expression was more expressed in the small intestine tumors (100%) than in those located in the duodenum (50%) The high risk tumors showed slightly more expression of Bcl-2 than the low risk ones (89% vs. 100%), despite the anatomical location. CONCLUSIONS: Both, p53 and Bcl-2 are important markers to establish the anatomical site of GIST and are also helpful to predict the clinical behavior of these tumors.

Enfermedad de Kikuchi-Fujimoto (linfadenitis histiocítica necrosante): Estudio clinicopatológico e inmunohistoquímico de 14 casos y su diagnóstico diferencial con otras linfadenitis necrosantes reactivas y neoplásicas / Kikuchi-Fujimoto disease (histiocytic necrotizing lymphadenopathy) clinicopathologic and immunohistochemical study of 14 cases and its differential diagnosis with other reactive and neoplastic necrotizing lymphadenopathies

Kikuchi-Fujimoto disease also known as histiocytic necrotizing lymphadenopaty (HNL) is a rare entity, originally described in Japanese population, although currently it has been described all over the world. It is more frequent in young women and it is usually located in cervical lymph nodes. We report 14 cases of HNL in Mexican population, their clinicopathological and immunohistochemical study as well as a comparative study with other necrotizing lymphadenopaties due to B or T-cell lymphomas, tuberculosis, Epstein Barr virus infection, and non-specific necrosis. In our study we found that there was more expression of the immunomarkers CD68, MPO, CD123 and antikerat in OSCAR in the cases of HNL in contrast with the lesser or even null expression of the same markers in the necrotized lymph nodes of the comparative study group.

La enfermedad de Kikuchi-Fujimoto o linfadenitis histiocítica necrosante (LHN) es una entidad poco frecuente, inicialmente descrita en población japonesa. Sin embargo, actualmente se ha descrito alrededor de todo el mundo. Es más frecuente en mujeres jóvenes y su localización habitual es en ganglios linfáticos cervicales. Presentamos estudio clinicopatológico de 14 casos de LHN en pacientes mexicanos, y los comparamos con linfadenitis necrosantes secundarias a linfomas B y T, tuberculosis, virus de Epstein Barr y necrosis inespecífica. Encontramos mayor expresión de los anticuerpos CD68, MPO, CD 123 y antiqueratina OSCAR en los casos de LHN comparados con la expresión baja o nula de los mismos anticuerpos en las necrosis ganglionares del grupo comparativo.

Glioblastoma multiforme with small cell neuronal-like component: association with human neurotropic JC virus.

The human polyomavirus JCV, the etiological agent of progressive multifocal leukoencephalopathy, has been associated with primitive neuroectodermal tumors and various glial-derived tumors, including glioblastoma multiforme (GBM). Here we describe the unique clinical case of a 54-year-old man who presented with headaches, hemiparesis and drowsiness. T1 and T2 magnetic resonance images revealed a large solid tumor with a cystic component located in the right temporal lobe, with extension into the parietal lobe. Histologically, the tumor was composed of two areas, a main area of large neoplastic cells with pleomorphic atypical nuclei and abundant cytoplasm, which by immunohistochemistry was reactive for glial fibrillary acidic protein, mixed with several foci of poorly differentiated tumoral cells with elongated nuclei and scant cytoplasm, negative for GFAP, but robustly immunoreactive for synaptophysin and phosphoneurofilaments. Results from PCR in laser capture microdissected cells from both areas of the tumor revealed the presence of DNA sequences corresponding to the early, late and control regions (CR) of the JCV genome and expression of JCV proteins T-antigen and Agnoprotein in both phenotypes. No evidence for capsid protein was observed, excluding productive viral infection. Sequencing demonstrated the presence of the JCV Mad-1 strain with distinct point mutations in the CR of isolates from both, GBM and small cell architectural areas. The presence of JCV DNA sequences and expression of viral proteins further reinforces the role of the widely spread human neurotropic virus in early transformation and in the development of brain tumors.

[Kikuchi-Fujimoto disease (histiocytic necrotizing lymphadenopathy) clinicopathologic and immunohistochemical study of 14 cases and its differential diagnosis with other reactive and neoplastic necrotizing lymphadenopathies]. / Enfermedad de Kikuchi-Fujimoto (linfadenitis histiocítica necrosante). Estudio clinicopatológico e inmunohistoquímico de 14 casos y su diagnóstico diferencial con otras linfadenitis necrosantes reactivas y neoplásicas.

Kikuchi-Fujimoto disease also known as histiocytic necrotizing lymphadenopaty (HNL) is a rare entity, originally described in Japanese population, although currently it has been described all over the world. It is more frequent in young women and it is usually located in cervical lymph nodes. We report 14 cases of HNL in Mexican population, their clinicopathological and immunohistochemical study as well as a comparative study with other necrotizing lymphadenopaties due to B or T-cell lymphomas, tuberculosis, Epstein Barr virus infection, and non-specific necrosis. In our study we found that there was more expression of the immunomarkers CD68, MPO, CD123 and antikerat in OSCAR in the cases of HNL in contrast with the lesser or even null expression of the same markers in the necrotized lymph nodes of the comparative study group.

[Cholesterol ester storage disease]. / Enfermedad por depósito de ésteres de colesterol.

The goal of this paper is to present a clinical case of a 4 year old boy, with hepatomegaly, splenomegaly and intestinal lipid infiltration due to a inborn error of lipid metabolism known as cholesterol ester storage disease. The main clinical manifestations were hepatomegaly, splenomegaly, hypertriglyceridemia, hypercholesterolemia. Duodenal endoscopy showed a yellow appearance of the mucous, and the histological study revealed the presence of macrophages with granular material. Liver biopsy showed steatosis infiltration at the hepatocytes, and macrophages with lipids. This disease is due to a lisosomal acid lipase partial deficiency, that is a glicoprotein that metabolize the hydrolysis of ester of cholesterol and triglycerides. The name of this pathology is cholesterol ester storage disease, but when the deficiency is total the name is Wolman's disease. We conclude that in all the children whit a clinical picture of hepatomegaly, splenomegaly, hypertriglyceridemia and hypercholesterolemia it is obligatory to rule out an inborn error of lipid metabolism like Wolman's disease or cholesterol ester storage disease.

Intestinal intussusception associated with adenovirus infection in Mexican children.

Formalin-fixed intestinal tissue specimens from 12 Mexican pediatric patients with intussusception were examined for the presence of adenovirus. Four patients (33%) had detectable adenovirus antigen in epithelial cells as determined by using immunohistochemical analysis. Two of the patients with positive immunohistochemical results had antigens in dendritic and mononuclear inflammatory cells, and 3 patients had positive results for species C adenovirus by in situ hybridization using adenovirus species-specific probes (A-F). A real-time polymerase chain reaction assay specific for species C (nonenteric) adenoviruses was used to confirm immunohistochemical results and to amplify adenovirus DNA for sequencing. A sequence similar to that for adenovirus serotype 1 was found in 1 patient, serotype 2 in another, and serotype 6 in a third; in the fourth patient, the sequence was indeterminate between serotypes 2 and 6. The assays used in this study proved useful for the identification of species C adenoviruses in formalin-fixed specimens from Mexican pediatric patients with intussusception.

Cerebral malignant nerve sheath tumor, triton tumor variant: case report.

A case of a cerebral malignant triton tumor in a 3-year-old boy with a 2-month history of frontal headache and no clinical evidence of neurofibromatosis is reported. The computed tomography (CT) scan showed a large, irregular tumor in the right parietooccipital lobe. A partial surgical resection was performed. Histologically, the tumor was highly cellular and consisted of spindle cells with hyperchromatic and pleomorphic nuclei. Focally, neoplastic cells with rhabdomyoblastic features were found. The immunohistochemical study showed that tumor cells were positive for S-100 protein and CD57, and the rhabdomyoblasts expressed desmin, Myo-D1, and myoglobin. During the postoperative period, a massive intraparenchymal hemorrhage was identified and surgical drainage was performed. The patient worsened and died 10 days after the first surgery. Postmortem study was not authorized. Six cases of cerebral malignant nerve sheath tumor have been described; however, primary intraparenchymal malignant triton tumor has not been previously described.

[Breast angiosarcoma in a patient with multiple surgical procedures and breast implant. Report of a case]. / Angiosarcoma de la mama en paciente con cirugías múltiples e implante mamario. Informe de un caso.

We report the case of a 39 years old woman, with bilateral fibrocystic breast disease and several surgeries for this cause, including bilateral mammary implants. Nineteen months after the implants an angiosarcoma of the left breast was diagnosed. In the specimen from radical mastectomy infiltration of the adipose tissue was found but no metastases to the axillary lymph node resected. Prognostic factors were investigated in surgical specimen and immunophenotypic characterization was made, considering Ki-67 and p53 expression. The patient finished chemotherapic treatment and is well, without neoplastic disease relapse, 16 months after diagnosis. We comment the possible relation between silicona's implants and angiosarcoma's genesis, association not reported before in the literature. The adverse effects of silicone implants and angiosarcoma histogenesis were reviewed.

Melanoma primario en el esófago. Caso inusual con esófago de Barrett / Primary melanoma in the esophagus. An unusual case with Barrettïs esophagus

Objetivo: presentar una entidad clinicopatológica rara, de difícil diagnóstico preoperatorio. Antecedentes: el melanoma primario esofágico no rebasa 0.1 por ciento de todas las neoplasias malignas en esta región, y puede asociarse con melanocitosis y melanosis en mucosa esofágica. Aunque la presentación clínica es semejante a la de cualquier otra neoplasia en el esófago, el comportamiento de los melanomas es más agresivo y fatal en la mayoría de los casos. La endoscopia generalmente muestra lesiones vegetantes no obstructivas, la pigmentación es oscura de la variante melánica, la única evidencia sugestiva diagnóstica previa al estudio microscópico. Es indispensable descartar clínicamente la posibilidad de un melanoma metastásico. Método: se revisan las características clínicas, imagenológicas, endoscópicas y anatomopatológicas de una neoplasia ulcerovegetante en la unión esofagogástrica, resecada a un hombre de 65 años de edad, que padecía disfagia progresiva. El paciente ha permanecido sin recidiva tumoral durante 18 meses ulteriores a la cirugía. Resultados: la masa tumoral resultó ser un tumor de células anaplásicas, con pigmentación melánica muy focal, teñido de manera difusa con el antígeno HMB-45 y la proteína S100, considerándolo como melanoma esofágico primario. La mucosa aledaña mostró un típico esófago de Barrett con hiperplasia melanocítica. Conclusiones: 1) la endoscopia puede sugerir la posibilidad de melanoma esofágico cuando se observa un tumor vegetante no obstructivo y pigmentado; 2) la inmunohistoquímica corrobora la entidad con la positividad para HMB-45 y S100, la negatividad para queratina y antígeno común leucocitario descartan carcinoma y linfoma, y 3) en este caso, la presencia de esófago de Barrett es excepcional, porque no ha sido descrita previamente en la literatura revisada.

Tumores sólidos seudopapilares del páncreas / Solid pseudopapillary tumors of the pancreas

El informe de tumores sólidos seudopapilares del páncreas, lesiones de potencial maligno incierto o francamente malignos, ha venido incrementándose a partir de su más amplio reconocimiento y caracterización como entidad anatomoclínica distintiva. Se les estima una frecuencia del 2 por ciento entre todas las neoplasias exocrinas del páncreas. Crecen lentamente sin correlación exacta entre aspecto histológico y comportamiento biológico. Presentamos los casos de dos pacientes femeninas de 24 y 15 años (casos 1 y 2), con excelente evolución luego del diagnóstico posquirúrgico, en el Centro Médico ABC de la Ciudad de México, de tumores sólidos seudopapilares del páncreas. Acudieron al hospital, por dolor abdominal, en el segundo caso precedido de trauma leve. El primer caso fue predominantemente quístico y el segundo predominantemente sólido, con 14 y 12 cm de diámetro respectivo. La histología, semejante en ambos, consistió en zonas sólidas y áreas de aspecto papilar con cambios mixoides. La inmunotinción destacó positividad para vimentina, expresión variable para marcadores neuroendocrinos, citoqueratina, receptores de progesterona y un hallazgo interesante: complejos ductuloinsulares en páncreas residual. Conclusiones: Ocurrencia en mujeres jóvenes; aspecto sólido-quístico; fácil exéresis; gran tamaño e histología sólida-papilar sugieren diagnóstico de tumor sólido seudopapilar pancreático, pudiendo evitar resecciones quirúrgicas excesivas.

Metástasis de carcinoma mamario lobulillar a vesícula biliar: estudio con inmunohistoquímica de receptores hormonales / Mammary lobular carcinoma metastatic to the gallbladder: immunohitochemistry and estrogen/progesterone receptors study

Se presenta un caso de carcinoma mamario lobulillar que cinco años después presenta metástasis a vesícula biliar. La metástasis fue sospechada por el estudio histológico y confirmada por medio de inmunohistoquímica para receptores de estrógenos y progesterona.

Páncreas ectópico en vesícula biliar. Hallazgo incidental / Ectopic pancreas in gallbladder. An incidental finding

Se informa el caso de un paciente de 35 años de edad con diagnóstico de colecistitis crónica alitiásica, que fue intervenido mediante cirugía laparoscópica, durante la cual se encontró incidentalmente páncreas ectópico en la serosa del cuello de una vesícula inflamada y colesterolosis polipoide

Amiloidoma hepático / Hepatic amyloidoma

Se presenta un caso clínico excepcional al diagnosticarse en forma incidental amiloidoma hepático sin enfermedad sistémica asociada, en un paciente masculino de 63 años de edad, quien acudió a consulta por presentar un cuadro clínico de esofagitis por reflujo con esófago de barrett y colecistitis crónica alitiásica. El paciente fue intervenido por vía laparoscópica, practicándole funduplicatura parcial de 270 grados (Touppet), colecistectomía y biopsia de lesión de aspecto granulomatoso en hígado, donde se encontró una lesión compuesta por material amorfo eosinófilo de tipo amiloide (amiloidoma)

Opportunistic infections in children with AIDS/HIV. A study of twenty five autopsies from the National Institute of Pediatrics in Mexico City

Veinticinco niños que murieron con SIDA/infección por VIH fueron sometidos a estudio postmortem; representan el 1.5 por ciento de las autopsias efectuadas desde enero de 1986 a junio de 1996. incluyen 16 pacientes infectados por vía materna y 6 por transfusión. Solo un caso se infectó por vía sexual y en dos casos se desconoce el mecanismo de infección. La infección materna en los 16 casos de infección vertical fue por transfusión prenatal en 5 transfusión postnatal en 4, sexual en 5 y no se determinó en un caso. La infección secundaria fue la causa de muerte en 23 de los 25 casos. La infección bacteriana estuvo presente en 56 por ciento de los niños infectados por vía materna y en 33 por ciento de los infectados por transfusión. Pseudomonas en 6 casos y Salmonella B en 4 fueron las bacterias mas frecuentes. Los gérmenes oportunistas fueron frecuentes, en especial Histoplasma (4 casos), Citomegalovirus (9 casos) y Herpes/Varicela (5 casos)