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Osteosarcoma (Os) is the most common malignant bone tumor in childhood and not rare in adults. In recent years, much research has focused on the role of angiogenesis in tumor development, growth, invasion, and metastasis. The aims of this study were to characterize neovascularization established between the xenotransplanted Os and the host at histological, immunohistochemical, ultrastructural, and molecular level, and to evaluate if this model could be used in testing new anti-angiogenic drugs. Three xenotransplanted human Os were evaluated. Tumor pieces 3-4 mm in size were implanted subcutaneously on the back of athymic Balb-c nude mice ( n = 14). The animals were killed at 24, 48, and 72 h and 7, 14, 21, and 28 days after implantation. Tumor samples were either fixed in 10 % formaldehyde and embedded in paraffin for histological analysis, or fixed with glutaraldehyde (2 %) for electron microscopy or retained non-fixed for molecular analysis (ELISA and qRT-PCR). Morphologically, intense neo-vasculogenesis within tumor parenchyma was present between the first and third week after transplantation. Immunohistochemistry demonstrated overexpression of VEGF and their receptors together with PDFGFRA 24-48 h after tumor implantation. Additionally, neoplastic cells co-expressed chemokines (CXCL9, CXCL10, and GRO) and their receptors. Molecular studies showed two expression profiles, distinguishing an early and a late phase in the angiogenic process. In Os, our model showed two stages of induced angiogenesis, with close association between histological and molecular events. This approximation could be of use for testing the effect of different anti-angiogenic agents. [ABSTRACT FROM AUTHOR]

Non-seminomatous germ cell tumours of the testis (NSGCT) form a heterogeneous group of neoplasms. Cell lines derived from NSGCT may provide useful data concerning the biology of neoplasic precursor germ cells, differentiation of tumour stem cells and the relationship between various tissue components of these tumours. Four NSGCT were studied, two mixed tumours composed of teratocarcinoma, yolk sac and trophoblastic elements, and two malignant teratomas with a massive neuroectodermal component, equivalent to primary neuroectodermal tumours (PNET) of the testis. The explanted tumours gave rise to various cell populations, including epitheloid cells, flattened large cells, spindle cells and tear drop cells of neuroblastic type. Ultrastructurally, cultured cells expressed various degrees of neural and muscular differentiation: neurosecretory granules, intermediate filaments of glial nature, and filaments resembling Z-bands. Cultured cells showed the expression of several neural and muscular markers, including neurofilaments, cytokeratin, actin, desmin, neuron-specific enolase, glial fibrillary acidic protein and HNK-1. In addition, three cases expressed HBA-71 antigen and two expressed MyoD1 protein. All cases were aneuploid, and an isochromosome 12p, i(12p), was detected in three cases. Myoblastic and neural cells are the predominant tumour cells that grow in vitro, independent of the nature and composition of the primary germ cell tumour. A histogenetic relationship between germ cell tumours and small round cell tumours of childhood is suggested. [ABSTRACT FROM AUTHOR]

The present study describes a new case of EWSR1-negative undifferentiated sarcoma with CIC/DUX4 gene fusion. This case is similar to tumors described as primitive undifferentiated round cell sarcomas that occur mainly in the trunk and display an aggressive behavior. To our knowledge, this is the first report of such a tumor presenting locoregional lymph node metastasis. In view of previous studies that prove the existence of a particular variant of undifferentiated sarcoma with Ewing-like morphology and CIC/DUX-4 gene fusion, a search for this gene fusion in all undifferentiated round cell sarcomas should be considered if a conclusive diagnosis cannot be reached following other conventional studies. Although additional cases with more extensive follow-up studies are needed, we believe that EWSR1-negative undifferentiated small round cell sarcoma with CIC/DUX4 gene fusion should be added to the list of new sarcoma variants with the possibility of lymph node metastasis. [ABSTRACT FROM AUTHOR]

The present study describes a new case of EWSR1-negative undifferentiated sarcoma with CIC/ DUX4 gene fusion. This case is similar to tumors described as primitive undifferentiated round cell sarcomas that occur mainly in the trunk and display an aggressive behavior. To our knowledge, this is the first report of such a tumor presenting locoregional lymph node metastasis. In view of previous studies that prove the existence of a particular variant of undifferentiated sarcoma with Ewing-like morphology and CIC/ DUX- 4 gene fusion, a search for this gene fusion in all undifferentiated round cell sarcomas should be considered if a conclusive diagnosis cannot be reached following other conventional studies. Although additional cases with more extensive follow-up studies are needed, we believe that EWSR1- negative undifferentiated small round cell sarcoma with CIC/ DUX4 gene fusion should be added to the list of new sarcoma variants with the possibility of lymph node metastasis. [ABSTRACT FROM AUTHOR]

Galectin-1 (GAL-1) is frequently expressed in osteosarcomas. Although a valuable diagnostic marker to differentiate between chondroblastic osteosarcomas and conventional chondrosarcomas, it has not been tested in the Ewing sarcoma family of tumors (ESFTs). We studied by immunohistochemistry GAL-1 expression in 43 osteosarcomas, 23 chondrosarcomas, and 217 genetically confirmed ESFTs using a tissue microarray. GAL-1 was expressed in 78 % of osteosarcomas, 33 % of chondrosarcomas, and 8 % of ESFTs. Osteoblastic and small cell osteosarcoma subtypes expressed GAL-1 in a high percentage of cells when compared with the other histological subtypes, whereas two chondroblastic osteosarcomas were negative. GAL-1 was mainly expressed in high-grade chondrosarcomas (grade III). ESFTs were rarely positive (8 %), and this was not related to the histological subtype nor to the clinical outcome. Although GAL-1 expression distinguishes chondroblastic osteosarcomas from conventional chondrosarcomas and is usually negative in conventional chondrosarcomas, the final diagnosis needs to incorporate histopathology since some chondroblastic osteosarcomas fail to express GAL-1, while high-grade chondrosarcomas are GAL-1 positive. Since GAL-1 is frequently expressed in osteogenic tumors, including small cell osteosarcoma, but rarely positive in ESFTs, its expression seems a valuable tool for distinguishing between these lesions. GAL-1 immunoexpression is not indicative of prognosis in ESFT. [ABSTRACT FROM AUTHOR]

The objectives of this work are to study angiogenesis in pancreatic ductal adenocarcinoma using computerized morphometric and image analysis and to compare the microvascular density in intratumoral and peritumoral areas and normal pancreatic tissue. Microvascular density was analyzed in 60 cases of pancreatic ductal adenocarcinoma and 30 samples of normal pancreatic tissue using an avidin-biotin immunoperoxidase technique with an anti-CD31 antibody. Microvascular density (MVD) was analyzed through digital microimaging and computerized analysis. The blood vessel density in the tumor was significantly higher than in peritumoral areas and in normal pancreatic tissue. Well differentiated pancreatic ductal adenocarcinomas contained higher MVD than poorly differentiated carcinomas. In pancreatic adenocarcinoma, MVD is higher than in peritumoral tissue or normal pancreatic tissue. [ABSTRACT FROM AUTHOR]

Epithelial marker and adhesion molecule expression has been reported in Ewing's sarcoma family of tumors (ESFTs), although the prognostic significance has not been assessed systematically. We performed immunohistochemical analysis of epithelial cell adhesion molecule and epithelial mesenchymal transition markers on 415 genetically confirmed ESFTs. Survival analyses were performed in 217 patients. The atypical histological subtype expressed a high proportion of the epithelial markers compared with conventional and PNET variants. We observed that expression of desmoplakin ( p < 0.001) and PI3K ( p = 0.003) was higher in disseminated than in localized disease. Multivariate analysis showed that desmoplakin and pGSK3β constitute independent good prognostic factors for progression free survival (PFS), while ZO-1 and Snail represent independent good prognostic factors for overall survival (OS). In contrast, CK8/18 represents an independent poor prognostic factor for OS and the radiotherapy treatment group demonstrated an independent poor prognostic factor for PFS and OS. Although the expression of pan-cytokeratin has been previously highlighted in a significant proportion of ESFT, its expression did not reveal prognostic significance in the present series. Considering the results of prognostic analysis herein reported, we strongly recommend a prospective validation of at least the immunomarkers with prognostic significance (desmoplakin, ZO-1, CK8/18, pGSK3β, and Snail) in prospective series that include localized and disseminated tumors. [ABSTRACT FROM AUTHOR]

During the 25-year period subsequent to the Chernobyl accident, the morbidity of malignant renal tumors in Ukraine has increased from 4.7 to 10.7 per 100,000 of the total population. Recent studies of our group have shown that increases in morbidity, aggressiveness, and proliferative activity of renal cell carcinomas (RCCs), especially clear-cell renal cell carcinoma (CCRCC), in Ukrainian patients continuously inhabiting the radio-contaminated areas could be explained by specific molecular changes influenced by the so-called 'chronic persistent low-dose ionizing radiation' (CPLDIR) exposure. This study aimed to examine the role of angiogenesis in CCRCC carcinogenesis associated with CPLDIR in patients living more than 20 years in cesium 137 (Cs) contaminated areas after the Chernobyl accident in Ukraine. Paraffin-embedded specimens of 106 CCRCs were studied: Control cases were 18 tumors from Spanish patients (group 1), 25 tumors from Ukrainian patients from so-called clean areas without known radio-contamination (group 2), and 63 tumors from Ukrainian patients from radio-contaminated areas (group 3). For intratumoral microvessel density (MVD) determination, anti-CD31 antibody was used. A computerized image analysis program was used to quantitatively calculate the vascular density. Seventy-three percent of group 3 and 72 % of group 2 CCRCCs displayed the highest MVD. A striking increase in MVD was seen in group 3 CCRCCs, in comparison with groups 1 and 2 ( p < 0.001). The majority of the hot spot vessels in group 3 was poorly differentiated. Moreover, MVD values for total vessels as well as for capillaries and tumor grade were strongly correlated. When we compared only tumor-node-metastasis tumor stages I and II, the differences remained statistically significant ( p < 0.1). The ratio of the average total vessels and capillaries in the Ukrainian groups combined was 1.65:1 in comparison to the Spanish group. Our results provide evidence that CPLDIR exposure increases MVD (particularly capillary) in CCRCCs and is associated with a higher histological grade. [ABSTRACT FROM AUTHOR]

Epithelial marker expression has been reported in Ewing's sarcoma family of tumors (ESFT). However, cytokeratin (CK), epithelial membrane antigen (EMA), and carcino embryonic antigen (CEA) prevalence has not been assessed thoroughly in a large series of genetically confirmed ESFT. The aim of the present study is to confirm the presence of epithelial markers in a large group of ESFT tested genetically for any of their specific gene fusions and the differential diagnosis with other small round cell tumors. To establish the prevalence of epithelial markers, we then performed immunohistochemical studies with antibodies CK (AE1/AE3), CK8/18, CK34β12, EMA, E-cadherin, and CEA on 415 genetically confirmed ESFT. Immunoreactivity to cytokeratin, EMA, and CEA was present in 19.2%, 6.6%, and 20.8% of cases, respectively. There was no significant association between epithelial markers and histological subtypes, but the atypical variant of ESFT expressed these markers in a high proportion compared with the peripheral neuroectodermal tumors and the conventional variant. The present findings confirm that epithelial marker expression in ESFT, including EMA and CEA, does not rule out a diagnosis of ESFT, and the integration of clinical, radiological, histopathological, immunohistochemical, and molecular genetic findings should form the basis for the diagnosis of bone and soft tissue sarcomas, especially in tumors with atypical or unusual phenotype. [ABSTRACT FROM AUTHOR]

We determined whether ubiquitylation and sumoylation processes are involved in conventional renal cell carcinogenesis associated with chronic, long-term, persistent low doses of ionizing radiation (IR) in patients living for more than 20 years in cesium-137 ((137)Cs)-contaminated areas after the Chernobyl accident in Ukraine. To this end, we assessed the immunohistochemical expression of ubiquitin (Ub), SUMO1, SUMO E2 conjugating enzyme Ubc9, and the cell cycle regulators p53, mdm2, and p14(ARF) in 38 conventional renal cell carcinomas from Ukrainian patients with different degrees of radiation exposure after the Chernobyl accident. As control cases, 18 conventional renal carcinoma (cRCC) tissues from a Spanish cohort were analyzed. No significant differences between the Ukrainian and Spanish groups were found regarding Ub overexpression, although being higher in the Ukrainian cases. Furthermore, this expression was inversely associated with SUMO1 and Ubc9, with no correlation with tumor nuclear grade. There was also a direct relationship between Ubc9 and inflammatory response. These findings do not allow us to consider the immunohistochemical expression of ubiquitylation and sumoylation as valuable markers for discriminating the effects of long-term, low-dose IR exposure in cRCC carcinogenesis. [ABSTRACT FROM AUTHOR]

Ewing's sarcoma family of tumours (ESFT) comprises a group of small round cell tumours (SRCT) genetically defined by specific chromosomal translocations resulting in a fusion of the EWSR1 gene with a member of the ETS family of transcription factors. Atypical ESFT are the most challenging of the ESFT subtypes, and the differential diagnosis with other SRCT of bone and soft tissue is difficult since these subtypes can resemble other neoplasms. The present article describes nine cases of genetically confirmed, atypical ESFT, having unusual alterations at morphological and immunohistochemical (IHC) levels associated with atypical clinical presentation mimicking sarcomas, carcinomas and lymphomas. Present results demonstrate that ESFT showing overlapping morphological and immunohistochemical features with other SRCT of soft tissue and bone, or even with carcinomas or lymphoma, can be differentiated using molecular techniques. In SRCT with EWSR1 translocation demonstrated by FISH, the RT-PCR analysis of specific sarcoma-related gene fusion can offer important clues for the diagnosis of specific entities, especially in tumours with unusual histopathology and/or IHC findings. Thus, we confirm that the integration of clinical, histopathological, IHC and genetic data becomes decisive in the diagnosis of bone and soft tissue sarcomas. [ABSTRACT FROM AUTHOR]

Ewing's sarcoma (ES)/peripheral neuroectodermal tumor (PNET) are malignant neoplasms affecting children and young adults. We performed a study to typify the histological diversity and evaluate antibodies that may offer diagnostic/prognostic support. In total, 415 cases of genetically confirmed paraffin-embedded ES/PNET were analyzed on whole sections and in tissue microarrays. This study confirms the structural heterogeneity of ES/PNET, distinguishing three major subtypes: conventional ES (280 cases); PNET (53 cases); and atypical ES/PNET (80), including large cells, vascular-like patterns, spindle pattern, and adamantinoma-like configuration. All cases presented positivity for at least three of the four tested antibodies (CD99, FLI1, HNK1, and CAV1). CAV1 appeared as a diagnostic immunomarker of ES/PNET being positive in CD99-negative cases. Hence, the immunohistochemical analysis confirmed the diagnostic value of all four antibodies, which together cover more than 99% of the tumors, independently of the histological variety. The univariate analysis for survival revealed atypical ES as the only histological parameter apparently associated with less favorable clinical outcome, particularly in the subgroup of patients treated with surgery. In conclusion, the diagnosis of atypical ES is a challenge for the pathologist and needs support from molecular techniques to perform an optimal differential diagnosis with other small round cell tumors. [ABSTRACT FROM AUTHOR]

Abstract  Ewing’s sarcoma (ES)/peripheral neuroectodermal tumor (PNET) are malignant neoplasms affecting children and young adults. We performed a study to typify the histological diversity and evaluate antibodies that may offer diagnostic/prognostic support. In total, 415 cases of genetically confirmed paraffin-embedded ES/PNET were analyzed on whole sections and in tissue microarrays. This study confirms the structural heterogeneity of ES/PNET, distinguishing three major subtypes: conventional ES (280 cases); PNET (53 cases); and atypical ES/PNET (80), including large cells, vascular-like patterns, spindle pattern, and adamantinoma-like configuration. All cases presented positivity for at least three of the four tested antibodies (CD99, FLI1, HNK1, and CAV1). CAV1 appeared as a diagnostic immunomarker of ES/PNET being positive in CD99-negative cases. Hence, the immunohistochemical analysis confirmed the diagnostic value of all four antibodies, which together cover more than 99% of the tumors, independently of the histological variety. The univariate analysis for survival revealed atypical ES as the only histological parameter apparently associated with less favorable clinical outcome, particularly in the subgroup of patients treated with surgery. In conclusion, the diagnosis of atypical ES is a challenge for the pathologist and needs support from molecular techniques to perform an optimal differential diagnosis with other small round cell tumors. [ABSTRACT FROM AUTHOR]

Ubiquitin and telomerase immunohistochemical expression patterns in cervical cancer were compared with normal cervical tissue samples. Eighty-one cervical cancer cases and 22 normal exo-endocervical tissue were examined with polyclonal antibody for ubiquitin and 44G12 clone for telomerase using tissue microarrays. The results were interpreted using a semiquantitative scale The average age of patients was 50.67 years. The most frequent histological types were moderately differentiated epidermoid carcinoma (43.5%), according to the degree of differentiation, and endocervical adenocarcinoma (42.1%). Immunohistochemical findings were as follows: 98.7% of cervical cancers showed immunoexpression for ubiquitin and 52.6% for telomerase. Statistically significant differences were found in tumor immunoreactivity when compared with control tissue (p < 0.0007) for both biomarkers. There was no significant difference in biomarker expression at different histological types of tumors, although telomerase was less expressed in endocervical adenocarcinoma. Our findings confirm that abnormal immunoexpression pattern of ubiquitin and telomerase is common in HPV-positive cervical cancer, indicating the existence of an intense degradation of proteins, subsequent cellular immortalization and maintenance of the malignant phenotype. [ABSTRACT FROM AUTHOR]

Inflammatory fibroid polyp (IFP) is a benign reactive uncommon submucosal lesion of the gastrointestinal tract, the small intestine being the most common site of origin. Histologically, IFPs are characterized by spindle cells, a heavy inflammatory infiltrate including eosinophils and onion-sheet-like formation of lesional cells around blood vessels. We present a case report of an IFP harboring an activation mutation in the PDGFR alpha gene. The lesion was positive for CD34, PDGFR alpha, and p-PDGFR alpha immunostaining but was negative for c-KIT and desmin. After a sequencing analysis of KIT and PDGFR alpha, a mutation consisting of an in-frame deletion of codons 567-571 and a missense mutation in codon 566 (S566R) of PDGFR alpha was observed. This mutation could activate key cellular pathways with involvement in the pathogenesis of this entity. We concluded that more studies are necessary in order to clarify if this finding is a biologically distinct behavior or, on the contrary, represents a specific feature of the IFP. [ABSTRACT FROM AUTHOR]

Abstract  We aimed to detect truncated CCN3 protein variants in formalin-fixed paraffin-embedded samples of eight Wilms’ tumors using anti-K19M and novel domain-specific antibodies, anti-NH2, anti-NH3, anti-NH4, and anti-NH5 raised against C-terminal (CT) domain and modules 1, 2, 3, and 4 of the CCN3 protein, respectively. In Wilms’ tumors, all the domain antibodies except anti-NH4 exhibited both nuclear and cytoplasmic staining in blastema as well as primitive tubules. NH4 was detected only in the cytoplasm of tumor cells. Normal fetal kidneys revealed mainly cytoplasmic immunoreactivity for all antibodies in tubules and glomeruli, except for K19 and NH5, which showed some nuclear staining. Our data suggest expression of a truncated nuclear CCN3 variant lacking the thrombospondin type-1-like domain and cytoplasmic full-length CCN3 protein in Wilms’ tumor cells. In addition, normal fetal kidneys express mainly full-length protein mostly localized to cytoplasm. Truncated CCN3 protein in Wilms’ tumor cells may provide evidence for its tumorigenic role in these tumors. Uniform NH5 staining compared to variable expression of K19M indicates that using NH5 is a better approach for detecting the CT domain of CCN3 protein in archival specimens. Thus, the domain-specific antibodies represent valuable tools for detecting CCN3 protein variants in normal and neoplastic kidneys. [ABSTRACT FROM AUTHOR]

Abstract  In addition to clinical and biological factors, further valuable prognostic information in neuroblastoma (Schwannian stroma-poor) (NB) patients is provided by the histopathologic analysis and the application of the International Neuroblastoma Pathology Classification (INPC) system. The objective of this study was to assess the prognostic impact of the INPC classification in a series of NB (Schwannian stroma-poor) and its relation with other prognostic factors. One hundred eighty-two cases of NB were collected from the files of the Spanish Neuroblastoma Registry. Slides were reviewed, and NB cases were grouped into favorable and unfavorable categories according to INPC criteria, taking into account morphological features (mitosis–karyorrhexis index, histological subtype) and patient’s age at diagnosis. Other pathological [presence of calcifications, tissular components, and number of mitotic cells per 10 high-power field (HPF)], immunohistochemical (P-glycoprotein and Ki-67 protein expression) and genetic (MYCN amplification and chromosome 1p deletion) features were also studied. Statistical analyses of overall survival with Kaplan–Meier curves and a multivariate study using Cox regression were performed (40.3% of NBs were considered favorable and 59.7% unfavorable). Unfavorable NB showed a mean survival time of 57 months compared with 89 months in favorable cases. Advanced stage, more than ten mitoses per 10 HPF, Ki-67 expression in more than 30% of tumor cells, MYCN oncogene amplification and chromosome 1p deletion were observed more frequently in unfavorable NB. The Cox regression analysis demonstrated that clinical stage (International Neuroblastoma Staging System stage 4) and histological subtype (undifferentiated NB) were the most important factors that influence the overall survival (p<0.001). INPC classification results are major prognostic indicators in NB and should be considered in the therapeutic stratification of NB patients. [ABSTRACT FROM AUTHOR]

Abstract  This paper discusses the diversity of synovial sarcomas (SSs) [biphasic (BSS), monophasic fibrous (MFSS), and poorly differentiated (PDSS)] and tissue microarray (TMA) evaluation of the immunophenotypic and histological progression of SSs in nude mice using three TMAs comprising 11 primary SSs (8 MFSSs, 2 BSSs, and 1 PDSS) and their xenografts. BSS and MFSS progressively transformed to a similar undifferentiated phenotype with loss of glandular component in the xenografts. Epidermal growth factor receptor and SALL2 were expressed in primary tumors and xenografts. Enhanced bcl-2 and bax expression were noted in xenografts. Ki-67 overexpression in xenografts correlated with high mitotic index. Epithelial membrane antigen (EMA) and cytokeratin AE1/AE3 were detected in all original and xenografted SSs. Hierarchical clustering differentiated original MFSS and BSS, but their xenografts clustered together due to similar immunoexpression profile. Our study demonstrates definite phenotypic variability of BSS and MFSS in the xenografts. Differences in immunoexpression for various markers existed between primary tumor and xenografts but not between subtypes. Hierarchical clustering grouped TMA immunostaining data and confirmed immunophenotypic variability; however, it failed to reveal any immunophenotypic differences between SYT-SSX1 and SYT-SSX2 type tumors. Nonetheless, reverse-transcriptase–polymerase chain reaction detected SYT-SSX transcripts in all primary SSs and their xenografts, thereby demonstrating their genetic stability. [ABSTRACT FROM AUTHOR]

The present study was carried out in order to examine molecular alterations of extracellular matrix (ECM), associated with cell-cell communication in conventional (clear-cell) renal cell carcinomas (cRCCs) influenced by persistent long-term, low-dose ionizing radiation (IR) exposure to patients living more than 19 years after the Chernobyl accident in Cesium 137 (137Cs)-contaminated areas of Ukraine. The ECM major components such as fibronectin, laminin, E-cadherin/beta-catenin complexes and p53 tumor suppressor gene protein, and transforming growth factor beta 1 (TGF-beta1) were immunohistochemically (IHC) evaluated in cRCCs from 59 Ukrainian patients, which represented 18 patients living in non-contaminated areas and 41 patients from 137Cs-contaminated areas. In contrast, a control group of 19 Spanish patients with analogue tumors were also investigated. For IHC evaluation, a tissue microarray technique was used. Decrease or loss and abnormal distribution of fibronectin, laminin, E-cadherin/beta-catenin complexes accompanied by elevated levels of p53 and TGF-beta1 were detected in the Ukrainian cRCCs from 137Cs-contaminated areas with statistically significant differences. Thus, our study suggests that chronic long-term, low-dose IR exposure might result in global remodeling of ECM components of the cRCCs with disruption in peri-epithelial stroma and epithelial basement membranes. [ABSTRACT FROM AUTHOR]

Anaplastic carcinoma of the thyroid gland (ACT) is a highly malignant tumor that is almost invariably associated with a fatal outcome. It demonstrates a variety of peculiar histological features, with squamoid, giant cell and spindle cell growth patterns. The spindle cell variant of ACT is usually indistinguishable from a true sarcoma and it can simulate fibrosarcoma, malignant fibrous histiocytoma (MFH), hemangiopericytoma and angiosarcoma or rhabdomyosarcoma. Although a rhabdomyosarcomatous appearance has sometimes been mentioned in the literature, true skeletal muscle differentiation has never been consistently proved. We report two cases of ACT with rhabdomyosarcomatous differentiation, as demonstrated by means of immunohistochemistry and electron microscopy. Both cases disclosed a very similar histological appearance, with a main population of small, pleomorphic, round-to-oval cells arranged in a storiform pattern, admixed with scattered pleomorphic giant cells, an image similar to that of the usual type of MFH. Stains for epithelial markers showed only few, scattered, weakly positive cells. Thyroglobulin and calcitonin were negative in tumor cells in both cases. On the contrary, positivity to vimentin was strong and generalized. Immunomarkers of muscular differentiation showed a consistent positivity. At the ultrastructural level, the cells disclosed the same spindle and pleomorphic morphology, with large, bizarre nuclei and cytoplasm with abundant mitochondria, rough endoplasmic reticulum, secretory granules and lipid droplets. There were also cells with wide cytoplasm filled with filamentous material, either of actin or myosin, as well as Z-band material. In conclusion, the cases reported here show a clear-cut rhabdomyosarcomatous differentiation of ACT, confirmed both immunohistochemically and ultrastructurally, a feature not previously reported in the literature. These findings may contribute to the broadening of the differentiation spectrum of this unusual neoplasm. [ABSTRACT FROM AUTHOR]

Anaplastic carcinoma of the thyroid gland (ACT) is a highly malignant tumor that is almost invariably associated with a fatal outcome. It demonstrates a variety of peculiar histological features, with squamoid, giant cell and spindle cell growth patterns. The spindle cell variant of ACT is usually indistinguishable from a true sarcoma and it can simulate fibrosarcoma, malignant fibrous histiocytoma (MFH), hemangiopericytoma and angiosarcoma or rhabdomyosarcoma. Although a rhabdomyosarcomatous appearance has sometimes been mentioned in the literature, true skeletal muscle differentiation has never been consistently proved. We report two cases of ACT with rhabdomyosarcomatous differentiation, as demonstrated by means of immunohistochemistry and electron microscopy. Both cases disclosed a very similar histological appearance, with a main population of small, pleomorphic, round-to-oval cells arranged in a storiform pattern, admixed with scattered pleomorphic giant cells, an image similar to that of the usual type of MFH. Stains for epithelial markers showed only few, scattered, weakly positive cells. Thyroglobulin and calcitonin were negative in tumor cells in both cases. On the contrary, positivity to vimentin was strong and generalized. Immunomarkers of muscular differentiation showed a consistent positivity. At the ultrastructural level, the cells disclosed the same spindle and pleomorphic morphology, with large, bizarre nuclei and cytoplasm with abundant mitochondria, rough endoplasmic reticulum, secretory granules and lipid droplets. There were also cells with wide cytoplasm filled with filamentous material, either of actin or myosin, as well as Z-band material. In conclusion, the cases reported here show a clear-cut rhabdomyosarcomatous differentiation of ACT, confirmed both immunohistochemically and ultrastructurally, a feature not previously reported in the literature. These findings may contribute to the broadening of the differentiation spectrum of this unusual neoplasm. [ABSTRACT FROM AUTHOR]

Previous studies have shown that during the period subsequent to the Chernobyl accident, increases in morbidity, aggressivity and proliferative activity of renal-cell carcinomas (RCCs) in Ukrainian patients were recognized. The present paper describes the molecular alterations of those tumor suppressor genes located on chromosome 9p21 ( INK4a/ARF locus and p15 INK4B) in 26 primary renal-cell epithelial tumors from patients with different degrees of radiation exposure after the Chernobyl accident in Ukraine. Radiometric measurement of Cesium 137 ( 137Cs) was conducted with 1-day urine from all patients before surgery. Our results demonstrate that RCCs from patients living in the radio-contaminated areas showed aberrant hypermethylation of p14 ARF and p16 INK4A genes, associated with increased p38MAPK, p14 ARF, mdm2, cyclinD1 and Ki67 protein expression levels. Present findings show the possibility that chronic long-term low-dose radiation activates the INK4a/ARF locus, targeted by activation of the p38MAPK cascade. These actions could lead to disruptions and loss of cell cycle checkpoints and, thereby, to cellular transformation. [ABSTRACT FROM AUTHOR]

Small-cell carcinoma (SCC) of the urinary bladder is an infrequent neoplasia accounting for 0.5% of all tumors located at this level. There is a predilection for males over females with a 4:1 proportion and a median age of 66 years. In most cases, the initial diagnosis is made at the metastatic or progressive stage of the disease. For this study, we collected ten cases of SCC of the urinary bladder, diagnosed over a period of 16 years, to describe the morphological and immunocytochemical characteristics of these infrequent neoplasia. In all cases, clinical data such as age at presentation, personal background, clinical symptoms, stage, treatment, clinical outcome and present status were available. Primary antibodies included chromogranin, neuron-specific enolase, synaptophysin, PGP 9.5, HNK-1, cytokeratin 34betaE12, cytokeratin 20, thyroid transcription factor-1 (TTF-1), c-erbB2 (CB-11), p53 (DO7), and Ki67 (MIB-1). In addition to the expression of neural/neuroendocrine markers, immunostaining for p53 and c-erbB2 was found in 80% and 50% of cases, respectively. In this paper, we confirm the aggressive course of the neoplastic disease. The expression of c-erbB2 in 50% of cases opens up hypothetical new possibilities for the use of immunotherapy in such cases. [ABSTRACT FROM AUTHOR]

Previous studies have shown that during the period subsequent to the Chernobyl accident, increases in morbidity, aggressivity and proliferative activity of renal-cell carcinomas (RCCs) in Ukrainian patients were recognized. The present paper describes the molecular alterations of those tumor suppressor genes located on chromosome 9p21 ( INK4a/ARF locus and p15(INK4B)) in 26 primary renal-cell epithelial tumors from patients with different degrees of radiation exposure after the Chernobyl accident in Ukraine. Radiometric measurement of Cesium 137 ((137)Cs) was conducted with 1-day urine from all patients before surgery. Our results demonstrate that RCCs from patients living in the radio-contaminated areas showed aberrant hypermethylation of p14(ARF) and p16(INK4A) genes, associated with increased p38MAPK, p14(ARF), mdm2, cyclinD1 and Ki67 protein expression levels. Present findings show the possibility that chronic long-term low-dose radiation activates the INK4a/ARF locus, targeted by activation of the p38MAPK cascade. These actions could lead to disruptions and loss of cell cycle checkpoints and, thereby, to cellular transformation. [ABSTRACT FROM AUTHOR]

Small-cell carcinoma (SCC) of the urinary bladder is an infrequent neoplasia accounting for 0.5% of all tumors located at this level. There is a predilection for males over females with a 4:1 proportion and a median age of 66 years. In most cases, the initial diagnosis is made at the metastatic or progressive stage of the disease. For this study, we collected ten cases of SCC of the urinary bladder, diagnosed over a period of 16 years, to describe the morphological and immunocytochemical characteristics of these infrequent neoplasia. In all cases, clinical data such as age at presentation, personal background, clinical symptoms, stage, treatment, clinical outcome and present status were available. Primary antibodies included chromogranin, neuron-specific enolase, synaptophysin, PGP 9.5, HNK-1, cytokeratin 34ßE12, cytokeratin 20, thyroid transcription factor-1 (TTF-1), c-erbB2 (CB-11), p53 (DO7), and Ki67 (MIB-1). In addition to the expression of neural/neuroendocrine markers, immunostaining for p53 and c-erbB2 was found in 80% and 50% of cases, respectively. In this paper, we confirm the aggressive course of the neoplastic disease. The expression of c-erbB2 in 50% of cases opens up hypothetical new possibilities for the use of immunotherapy in such cases. [ABSTRACT FROM AUTHOR]

After the Chernobyl accident, the morbidity of renal-cell carcinomas in Ukraine increased gradually from 4.7 to 7.5 per 100,000 of the total population. Cesium 137 (137Cs) is responsible for 80-90% of the internal radioactivity in people living in radiocontaminated areas of Ukraine, and 90% of 137Cs is eliminated through the kidneys. Histological and immunohistochemical study of proliferating cell nuclear antigen (PCNA) and K-ras protein was performed in peritumoral kidney tissues of 167 Ukrainian patients (groups I-III, according to varying degrees of internal exposure to radiation), and of 85 analog Spanish patients, as a control group. Our data showed in the majority of Ukrainian patients a radiation sclerosing proliferative atypical nephropathy (RSPAN) in association with an increase in the incidences of tubular epithelial nuclear atypia and carcinoma in situ (CIS). Areas of epithelial nuclear atypia and CIS of the cortex and medulla showed significant PCNA expression with means of extent as 12, 14, and 15% of stained nuclei in groups I, II, and III respectively. K-ras expression of the same areas occurred in 67, 87, and 85% of cases in groups I, II, and III respectively. The present study points to a strong relationship between the long term of low-dose radiation exposure of the Ukrainian population and the development of RSPAN as a possible precursor of malignancy. In addition, it confirms the possible initiator, promoter, or progressor role of chronic low-level radiation of renal human carcinogenesis in Ukraine. [ABSTRACT FROM AUTHOR]

TP53 and MDM2 genes and their protein expression were evaluated in frozen and paraffin-embedded tissue from 27 patients with malignant fibrous histiocytoma to elucidate the relationship between them, their implication in tumor progression mechanisms and their possible diagnostic-prognostic value in malignant fibrous histiocytoma. Single-strand conformation polymorphism analysis and direct sequencing of polymerase chain reaction-amplified DNA were used to establish two TP53 mutations (7.4%): a point mutation and a 63-bp duplication. Amplification of the MDM2 gene was observed in two tumors (7.4%) by means of Southern-blot analysis, one of them also carrying the TP53 point mutation. Immunohistochemical and Western-blot techniques were used to study nuclear accumulation of p53 and mdm2 proteins: 11 cases (40.7%) with p53 protein expression and thirteen cases (48.1%) with mdm2 protein expression were detected. We confirmed overexpression of mdm2 protein in eight of ten cases (80%) with p53 protein expression without TP53 gene mutation. Statistical analysis shows that simultaneous co-expression of p53 and mdm2 in malignant fibrous histiocytoma is significantly correlated with survival in absence of gene alteration in contrast to the lack of statistical correlation with survival of p53 protein expression alone. [ABSTRACT FROM AUTHOR]

A new case of hepatoid adenocarcinoma was diagnosed in fragments obtained at transurethral resection (TUR) from a 71-year-old man who had complained of haematuria. The tumour was composed of trabeculae and small solid nests of polygonal atypical cells simulating hepatocarcinoma, together with glandular areas of an otherwise typical adenocarcinoma. Immunohistochemistry showed cytoplasmic reactivity to AFP, AAT, albumin and CAM 5.2. Membrane reactivity was seen in EMA immunostaining, and there was also positivity to polyclonal CEA following a canalicular pattern. Immunoperoxidase studies of hepatocyte growth factor (HGF) and its receptor, c-met, were positive. Their expression may be related to the aggressive behaviour of this tumour. [ABSTRACT FROM AUTHOR]

The incidence of p53 gene abnormalities in human hepatocellular carcinoma (HCC) varies in different geographical areas, being higher in regions where hepatitis virus infection and dietary exposure to aflatoxin B1 are the most common aetiological agents. These mutations are less frequently encountered in Europe, although some studies have reported p53 protein overexpression in up to 45% of cases analysed. We have analysed 129 tumour samples of primary malignant hepatic neoplasms recovered from paraffin blocks processed in two pathology laboratories in a Mediterranean area of Spain (Valencia and Gerona). Among 14 cases in which p53 immunohistochemistry expression proved positive, 5 stained in more than 50% of the cell nuclei. By PCR-SSCP analysis we could detect the complete sequence from exon 5 through 8 in 70 cases and part of this region in the remaining cases, but no mutations were found. We found no relationship with the clinical stage, tumour stage or clinical outcome. We conclude that p53 gene alterations are not a major event in the malignant transformation of hepatic cells in this region of the Mediterranean. The variable incidence of p53 gene alterations in other geographical areas may reflect a different genetic background for the aetiology of HCC. [ABSTRACT FROM AUTHOR]

Uterine sarcomas are approximately 3% of all malignant uterine corpus tumours. Of these, the tumours that originate solely in the stromal elements of the uterine wall are infrequent and have not been well characterized cytogenetically. We report two cases of endometrial stromal sarcomas (ESS), one low grade and one high grade, diagnosed by conventional histology, immunocytochemistry, electron microscopy and cytogenetics. Morphologically clear-cut differential structures were seen at optical, immunohistochemical, and electron microscopic levels, permitting a clear differential diagnosis. The low-grade ESS expressed hormonal receptors and vimentin, whereas the high-grade ESS showed no hormone receptors, high Ki-67 activity, and occasional cytokeratin-positive cells. Ultrastructurally, no malignant epithelial differentiation was seen in the tumour cells, but cilia were found in both cases. Cytogenetic study of the low-grade ESS showed pseudodiploid karyotype with chromosomes 6 and 20 rearranged. The high-grade ESS showed a complex karyotype with clonal numerical and structural anomalies. The chromosomes involved in the structural rearrangements were 1, 3, 6, 7, 13, 14, 15, 17, 19, and 21. [ABSTRACT FROM AUTHOR]

An immunohistochemical study on frozen sections was carried out on 51 malignant tumours of soft tissue and bone using the FU-3 monoclonal antibody. This antibody is claimed to be specific for malignant fibrous histiocytoma (MFH) and liposarcoma and for normal and tumour cells located in perivascular fields. The results show a lack of specificity in MFH staining: several malignant tumours such as synovial sarcoma, fibrosarcoma, rhabdomyosarcoma, osteogenic sarcoma, and including an anaplastic malignant melanoma, presented positive staining somewhat similar to that found in MFH. The value of this antibody in the differential diagnosis of MFH is doubtful. It might be useful to recognize a common pathway of terminal differentiation expressed by several pleomorphic sarcomatous neoplasms. [ABSTRACT FROM AUTHOR]