[Primary pulmonary rabdomyosarcoma: clinical-pathological and immunohistochemical findings]. / Rabdomiosarcoma pulmonar primario: hallazgos clínico-patológicos e inmunohistoquímicos.

Pulmonary rhabdomyosarcona is a rare entity and the histopatological differential diagnosis can be difficult. We report on a case of a 48-year-old male patient with a neoplasm located at the hilum of the right lung. The histological study of the lobectomy specimen allowed the diagnosis of embryonal rhabdomyosarcoma to be made. Given the absence of tumor lesions in other sites, it was classified as primary pulmonary neoplasm. The patient underwent chemotherapy and subsequently a completion pneumonectomy for recurrence of the tumor. One year after the initial surgery, he presented a metastasis in the right adrenal gland. He died 20 months after the original diagnosis. The importance of immunohistochemistry in the diagnosis is emphasized and the different theories that attempt to explain the histogénesis of these tumors in unusual sites are analyzed.

El rabdomiosarcoma pulmonar es una entidad rara y muy poco frecuente, más aún en la población adulta, lo que puede dificultar el diagnóstico correcto. Se presenta el caso de un varón de 48 años con un tumor pulmonar. El estudio histológico reveló que se trataba de un rabdomiosaroma embrionario pulmonar primario. Dada la ausencia de lesiones tumorales en otros sitios fue catalogado como primario pulmonar. El paciente realizó quimioterapia y posteriormente fue sometido a una neumonectomía por recidiva de la neoplasia. Al año de la cirugía inicial presentó una metástasis en glándula suprarrenal derecha. Falleció al cabo de 20 meses del diagnóstico original. Se enfatiza la importancia de la inmunohistoquímica en el diagnóstico y se analizan las distintas teorías vigentes que intentan explicar la histogénesis de estos tumores en sitios no habituales.

Rabdomiosarcoma pulmonar primario: hallazgos clínico-patológicos e inmunohistoquímicos / Primary pulmonary rabdomyosarcoma: clinical-pathological and immunohistochemical findings

Resumen El rabdomiosarcoma pulmonar es una entidad rara y muy poco frecuente, más aún en la población adulta, lo que puede dificultar el diagnóstico correcto. Se presenta el caso de un varón de 48 años con un tumor pulmonar. El estudio histológico reveló que se trataba de un rabdomiosaroma embrionario pulmonar primario. Dada la ausencia de lesiones tumorales en otros sitios fue catalogado como primario pulmonar. El pa ciente realizó quimioterapia y posteriormente fue sometido a una neumonectomía por recidiva de la neoplasia. Al año de la cirugía inicial presentó una metástasis en glándula suprarrenal derecha. Falleció al cabo de 20 meses del diagnóstico original. Se enfatiza la importancia de la inmunohistoquímica en el diagnóstico y se analizan las distintas teorías vigentes que intentan explicar la histogénesis de estos tumores en sitios no habituales.

Abstract Pulmonary rhabdomyosarcona is a rare entity and the histopatological differential diagnosis can be difficult. We report on a case of a 48-year-old male patient with a neoplasm located at the hilum of the right lung. The histological study of the lobectomy specimen allowed the diagnosis of embryonal rhabdomyosarcoma to be made. Given the absence of tumor lesions in other sites, it was classified as primary pulmonary neoplasm. The patient underwent chemotherapy and subsequently a completion pneumonectomy for recurrence of the tumor. One year after the initial surgery, he presented a metastasis in the right adrenal gland. He died 20 months after the original diagnosis. The importance of immunohistochemistry in the diagnosis is emphasized and the different theories that attempt to explain the histogénesis of these tumors in unusual sites are analyzed.

El análisis inmunohistoquímico para el diagnóstico del tumor fibroso solitario/hemangiopericitoma / Immunohistochemical analysis for the diagnosis of solitary fibrous tumor/hemangiopericytoma

Resumen El tumor fibroso solitario/ hemangiopericitoma (TFS/HP) es un tumor extraaxial de origen mesenquimático de infrecuente observación, que usualmente se confunde con el meningioma, del cual puede ser clínica y radiológicamente indistinguible. El análisis molecular con la detección de la expresión nuclear STAT6 (signal transducer and activator of transcription 6) o la fusión NAB2-STAT6 (NGFI-A binding protein 2) es recomendable para confirmar el diagnóstico. Presentamos 3 casos clínicos, 2 mujeres y 1 varón, con diagnóstico anatomopatológico de meningioma meningotelial en el primer caso; y los casos 2 y 3 con sospecha radiológica de meningioma. La revisión anatomopatológica con estudio molecular permitió certificar el diagnóstico de TFS/ HP. Para el diagnóstico diferencial entre TFS/HP meníngeo y meningioma, se recomienda buscar la expresión de STAT6 como primer paso o la fusión NAB2-STAT6. La revisión de las muestras de biopsia debe estar garantizada en todos los pacientes, inclusive en aquellas que fueron estudiadas en Servicios de Patología Nivel 3.

Abstract The solitary fibrous tumor/ hemangiopericytoma (TFS/HP) is a rare mesenchymal extraaxial tumour. TFS/HP can sometimes be difficult to distinguish from other extra-axial tumors like meningioma, which can be clinically and radiologically indistinguishable. Molecular analysis with STAT6 (signal transducer and activator of transcription 6) nuclear expression or NAB2-STAT6 (NGFI-A binding protein 2) fusion is recommended to confirm the diagnosis. We present 3 cases, 2 women and 1 male, with pathological diagnosis of meningothelial meningioma in the first case; cases 2 and 3 with radiological suspicion of meningioma. The pathological review with molecular study certified the diagnosis of TFS/HP. For differential diagnosis between meningeal TFS/HP and meningioma, it is recommended to look for STAT6 expression as a first step, or NAB2-STAT6 fusion in order to confirm TFS/HP. The review of biopsy samples must be guaranteed in all patients, including those who were studied in Pathology Services Level 3.

[Immunohistochemical analysis for the diagnosis of solitary fibrous tumor/ hemangiopericytoma]. / El análisis inmunohistoquímico para el diagnóstico del tumor fibroso solitario/ hemangiopericitoma.

The solitary fibrous tumor/ hemangiopericytoma (TFS/HP) is a rare mesenchymal extraaxial tumour. TFS/HP can sometimes be difficult to distinguish from other extra-axial tumors like meningioma, which can be clinically and radiologically indistinguishable. Molecular analysis with STAT6 (signal transducer and activator of transcription 6) nuclear expression or NAB2-STAT6 (NGFI-A binding protein 2) fusion is recommended to confirm the diagnosis. We present 3 cases, 2 women and 1 male, with pathological diagnosis of meningothelial meningioma in the first case; cases 2 and 3 with radiological suspicion of meningioma. The pathological review with molecular study certified the diagnosis of TFS/HP. For differential diagnosis between meningeal TFS/HP and meningioma, it is recommended to look for STAT6 expression as a first step, or NAB2-STAT6 fusion in order to confirm TFS/HP. The review of biopsy samples must be guaranteed in all patients, including those who were studied in Pathology Services Level 3.

El tumor fibroso solitario/ hemangiopericitoma (TFS/HP) es un tumor extraaxial de origen mesenquimático de infrecuente observación, que usualmente se confunde con el meningioma, del cual puede ser clínica y radiológicamente indistinguible. El análisis molecular con la detección de la expresión nuclear STAT6 (signal transducer and activator of transcription 6) o la fusión NAB2-STAT6 (NGFI-A binding protein 2) es recomendable para confirmar el diagnóstico. Presentamos 3 casos clínicos, 2 mujeres y 1 varón, con diagnóstico anatomopatológico de meningioma meningotelial en el primer caso; y los casos 2 y 3 con sospecha radiológica de meningioma. La revisión anatomopatológica con estudio molecular permitió certificar el diagnóstico de TFS/HP. Para el diagnóstico diferencial entre TFS/HP meníngeo y meningioma, se recomienda buscar la expresión de STAT6 como primer paso o la fusión NAB2-STAT6. La revisión de las muestras de biopsia debe estar garantizada en todos los pacientes, inclusive en aquellas que fueron estudiadas en Servicios de Patología Nivel 3.

Putative Biomarkers of Response to Treatment in Breast Cancer Patients: A Pilot Assay.

Identifying tumor biomarkers associated with clinical behavior in breast cancer patients may allow higher accuracy in the selection of treatment. Different types of cells were determined in the primary tumors of stage I, II, and III of breast cancer patients, who were assigned to one of the two groups: (1) disease-free or (2) relapsed/progressed, at 5 years after primary treatment. We studied 32 tumor samples. CD4+ lymphocytes and CD44+CD24-/low cells (cancer stem cells) showed a significant association with clinical outcome at 5 years of primary treatment, while CD8+, Foxp3+, CD34+, and myeloid-derived suppressor cells did not show any association. Coincident with the results of individual analysis, we identified CD4+ cells and CD44+CD24-/low cells as good predictors of long-term clinical outcome in a logistic regression.

DLG1 polarity protein expression associates with the disease progress of low-grade cervical intraepithelial lesions.

Human Discs large tumour suppressor (DLG1) participates in regulating cell polarity and proliferation, suggesting an important connection between epithelial organization and cellular growth control. However, it was demonstrated that DLG1 could acquire oncogenic attributes in some specific contexts. In this work, we evaluated the expression of DLG1 and its contribution to the progress of cervical lesions in order to investigate a potential role of this polarity protein in human oncogenic processes. We analyzed cervical biopsies from women with low-grade squamous intraepithelial lesion (LSIL) diagnosis (n=30), for DLG1 expression by immunohistochemistry. These results were correlated with the clinical monitoring of the patients during a 24-month follow-up period. Our data indicate that while all LSIL patients with a DLG1 staining pattern similar to normal tissues are significantly more likely to regress (n=23, Pattern I), all LSIL biopsy specimens showing a diffuse and intense DLG1 staining likely progress to high-grade lesions (n=4, Pattern II). Finally, all persistent LSIL analyzed showed an undetermined DLG1 staining, with a diffuse distribution without a strong intensity (n=3, Pattern III). We found a significant association between the expression pattern of DLG1 and the evolution of the lesion (p<0.00001). This work contributes to the knowledge of DLG1 biological functions, suggesting that its expression may have an important role in the progression of early dysplastic cervical lesions, giving prognostic information.

Alteration of the microRNA-122 regulatory network in rat models of hepatotoxicity.

MicroRNAs are small RNA molecules that post-transcriptionally regulate gene expression. MicroRNA-122 is the most abundant and specific liver microRNA. Hepatotoxicity involves a significant alteration of liver gene expression. The aim of this work was to evaluate the microRNA-122 regulatory network in models of hepatotoxicity induced by thioacetamide or carbon tetrachloride. We report that the toxins decreased the expression of microRNA-122, which corresponded with an increase in two target genes: Cyclin G1 and the cationic amino acid transporter CAT-1. We found a decreased expression of its precursor, pri-microRNA-122, and of the transcription factors that specifically bind its promoter: CCAAT/enhancer-binding protein alpha, and members of the hepatocyte nuclear factor family. Therefore, microRNA-122 expression levels are under transcriptional control during hepatotoxicity. We propose that the changes observed are associated with the liver response to cope with the injury caused by the hepatotoxins, likely through a cell proliferation process to repair the damaged tissue.

Gonadoblastoma: an unusual ovarian tumor.

Gonadoblastomas are unusual benign neoplasias that frequently appear in the dysgenetic gonads of women with chromosome Y anomaly. In this study, we reviewed 3 gonadoblastoma cases, 2 of which were bilateral, in patients 21, 17, and 18 years of age. Two of them presented 46 XY karyotype and gonadal dysgenesis, whereas the third presented 46 XX karyotype. Besides, 2 of the cases were associated to dysgerminomas. In all the cases, the histologic examination showed germ cell proliferation and sex cords derivatives frequently surrounding small round deposits containing amorphous hyaline material resembling Call-Exner bodies. One of the patients died at 8 years from diagnosis because of dysgerminoma multiple metastases, one is alive with no evidence of disease at the second year of follow-up, and the evolution of the third patient remains unknown.

Immunization with an engineered mutant trans-sialidase highly protects mice from experimental Trypanosoma cruzi infection: a vaccine candidate.

Chagas' disease is a major tropical disease for which a cure for chronic phase does not exist yet. Trypanosoma cruzi trans-sialidase (TS) seems to be involved in relevant processes such as infectivity, host survival and, very importantly, disease pathogenesis. In this study, we show that mice vaccinated with an engineered enzymatically deficient mutant TS containing the catalytic domain without the immunodominant SAPA (Shed Acute Phase Antigen) repeats, were highly protected against T. cruzi infection. Adult male BALB/c mice were immunized with mutant protein, purified from Pichia pastoris yeast, using three inoculations in Freund's adjuvant. All immunized mice were protected against challenge with a lethal dose of T. cruzi trypomastigotes. The protected immunized mice developed no clinical or tissue evidence of infection throughout the study. In contrast, 60-90% mortality and 100% occurrence of myocardial lesions were observed in the non-immunized counterparts. Titers of circulating antibody against TS did not correlate with protection, while anti-SAPA antibodies were coincident with disease severity. Further studies indicated that a single inoculation of mutant recombinant protein in Freund's complete adjuvant was not associated with blood or organic alterations, per se. Mutant TS vaccination seems to be a promising tool for immune intervention strategies in Chagas' disease, aimed at preventing T. cruzi-related heart tissue damage.

Ovarian thecoma: clinicopathological analysis of 50 cases.

The clinicopathological findings of 50 thecoma cases were studied to establish the most useful diagnostic criteria helpful in characterizing this ovarian stromal tumor. Patient age ranged from 21 to 77 years (median, 57.5 years). In this study, thecoma appears to be associated with endometrial diseases (15 patients) as an incidental finding in a gynecologic routine examination (14 patients) and in a cesarean delivery (1 patient). Arteries, veins, lymphatics, and mast cells are normally present in the ovarian medulla and are absent in the cortical area. The 50 thecomas studied showed proliferation of stromal cells and presence of arteries, lymphatics, and mast cells. Thecoma tumoral growth appeared to cause atrophy or compression of the cortical area. These findings are significant for diagnosis; thus, thecoma is proposed as a tumor originating in the ovarian medulla. Fibroma and thecoma seem to be different neoplasms and should be considered distinct, separate entities because they have different origin, morphology, and potential functionality.

Benznidazole, a drug used in Chagas' disease, ameliorates LPS-induced inflammatory response in mice.

Benznidazole (BZL) is a drug currently used for treating Chagas' disease. Given our earlier demonstration in which BZL downregulated cytokine and nitric oxide (NO) synthesis by LPS and/or IFN-gamma-stimulated murine macrophages, we have now analysed whether this compound could exert beneficial effects in a model of LPS-induced inflammation in C57BL/6 mice. The lethal model consisted of two LPS intraperitoneal injections, 200 microg each separated by 2 h, with BZL given orally at a dose of 200 mg/kg, 18 and 2 h before the first challenge and 20 and 44 hr following the second one. In this model, BZL treatment led to a significantly decreased mortality in comparison with untreated counterparts. Remaining experiments were carried out in mice given a unique LPS dose, pretreated with BZL or not, since those subjected to the lethal protocol were unsuitable for laboratory handling. Analysis of IL-1beta, IL-6, TNF-alpha, IL-12 and iNOS mRNA expression in liver samples taken at 90 min post-LPS showed a marked reduction of the two latter mRNAs in BZL-treated mice. These animals also displayed significantly decreased peaks levels of serum TNF-alpha and IL-6, accompanied by a diminished number of IL-6-producing peritoneal macrophages. Present effects may broaden the potential usefulness of BZL in situations accompanied by an excessive inflammatory response.

Differential expression of the human homologue of drosophila discs large oncosuppressor in histologic samples from human papillomavirus-associated lesions as a marker for progression to malignancy.

High-risk HPVs play a causal role in the development of cervical cancer, and their E6 oncoproteins target h-Dlg for ubiquitin-mediated proteolysis. The h-Dlg oncosuppressor is associated with cell-cell interactions, and deregulation of these structures leads to defective cell adhesion, loss of cell polarity and unregulated proliferation. We evaluated the contribution of this E6 activity in the progression to malignancy in HPV infections by analyzing h-Dlg expression in HPV-associated lesions. We analyzed h-Dlg in cervical, laryngeal, vulvar, colon and kidney histologic samples by Dlg immunohistochemistry. HPV association was ascertained by a PCR-colorimetric method. Although Dlg was certainly expressed in intraepithelial cervical, vulvar and laryngeal HPV-associated lesions, its cellular and tissue distribution patterns were altered compared to normal tissue. However, marked reduction in Dlg levels was observed in HPV-positive invasive cervical carcinomas. To elucidate whether the loss of Dlg was significant for carcinogenesis in general, we investigated Dlg expression in tumors not associated with HPV. In colon and kidney carcinomas, Dlg was expressed, albeit with a different pattern of distribution with respect to the normal tissue. The loss of Dlg may be considered a late-stage marker in cervical carcinogenesis, but alterations in its expression and localization take place during the different dysplastic stages. Dlg downregulation and/or alterations in its localization may contribute to transformation and may explain some of the characteristics of the malignant cells, such as loss of polarity and high migration ability.

Influencia de la edad de la rata en la evolución de la infección com trypanosoma cruzi / Influence of the age of the rat on the course of infection with trypanosoma cruzi

En la primera parte de este trabajo se estudió en la fase aguda, la parasitemia y respuesta inmune humoral específica, en ratas de línea "1", inoculadas al destete con 1x10**6 T. cruzi vivos de la cepa Tulahuén (GD), y adultos jóvenes con 1x10**6 T. cruzi (GA) y con 7x10**6 T. cruzi, cantidad equivalente a la inoculada en los destetes según peso (GA-1). La parasitemia fue significativamente mayor en el GD que en los GA y GA-1. Por otro lado, el GD presentó bajos títulos de anticuerpos, en relación a los adultos con ambas concentraciones de T. cruzi, que tuvieron un comportamiento similar. En el período crónico se evaluaron, a los 180 días post-infección, los ECG y la histolatología de corazón en animales al destete y adultos, con sólo 1x10**6 T. cruzi. La frecuencia cardíaca en los animales infectados fue mayor que la de los testigos. La proporción de lesión cardíaca (miocarditis, pericarditis y/o fibrosis) fue superior en el GD y en el GA, con respecto al GT, y el GA presentó un 35,6% de fibrosis, significativamente diferente de los otros grupos. La lesión fue sobre todo leve, ventricular y no se visualizaron parásitos in situ. En síntesis, en la rata, en la fase aguda de la infección, se encontraron diferencias marcadas en serología y parasitemia según la edad del huésped; sin embargo, la patología miocárdica crónica fue similar, con la excepción de que 1/3 de las ratas adultas inoculadas presentaron fibrosis (AU)

Influencia de la edad de la rata en la evolución de la infección com trypanosoma cruzi / Influence of the age of the rat on the course of infection with trypanosoma cruzi

En la primera parte de este trabajo se estudió en la fase aguda, la parasitemia y respuesta inmune humoral específica, en ratas de línea "1", inoculadas al destete con 1x10**6 T. cruzi vivos de la cepa Tulahuén (GD), y adultos jóvenes con 1x10**6 T. cruzi (GA) y con 7x10**6 T. cruzi, cantidad equivalente a la inoculada en los destetes según peso (GA-1). La parasitemia fue significativamente mayor en el GD que en los GA y GA-1. Por otro lado, el GD presentó bajos títulos de anticuerpos, en relación a los adultos con ambas concentraciones de T. cruzi, que tuvieron un comportamiento similar. En el período crónico se evaluaron, a los 180 días post-infección, los ECG y la histolatología de corazón en animales al destete y adultos, con sólo 1x10**6 T. cruzi. La frecuencia cardíaca en los animales infectados fue mayor que la de los testigos. La proporción de lesión cardíaca (miocarditis, pericarditis y/o fibrosis) fue superior en el GD y en el GA, con respecto al GT, y el GA presentó un 35,6% de fibrosis, significativamente diferente de los otros grupos. La lesión fue sobre todo leve, ventricular y no se visualizaron parásitos in situ. En síntesis, en la rata, en la fase aguda de la infección, se encontraron diferencias marcadas en serología y parasitemia según la edad del huésped; sin embargo, la patología miocárdica crónica fue similar, con la excepción de que 1/3 de las ratas adultas inoculadas presentaron fibrosis