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Differentiated Tumours (differentiated + tumour)
Selected AbstractsPoorly differentiated tumours of the anal canal: a diagnostic strategy for the surgical pathologistHISTOPATHOLOGY, Issue 1 2007B Balachandra Poorly differentiated malignancies affecting the anal canal are uncommon but pose diagnostic difficulties because of the wide range of normal cell types that may occur within a limited anatomical region. The range of lesions that may present as poorly differentiated tumours includes squamous cell carcinoma, adenocarcinoma, small and large cell neuroendocrine carcinoma, neuroendocrine carcinoma expressing epithelial cytokeratins and other patterns of mixed differentiation, undifferentiated carcinoma, malignant melanoma, lymphoma and secondary tumours. This review discusses the differential diagnosis of these neoplasms with the aid of short illustrative case studies. [source] Immunohistochemical analysis of heme oxygenase-1 in preneoplastic and neoplastic lesions during chemical hepatocarcinogenesis,INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 4 2004Fabiana Caballero Summary Heme oxygenase (HO) breaks down the pro-oxidant heme into carbon monoxide, iron and the antioxidant biliverdin. The isoform HO-1 plays an effective role to counteract oxidative damage and to control inflammation. Prolonged cellular damage due to chronic inflammation is one of the reasons leading to the development of tumours. The aim of this work was to investigate HO-1 expression and localization along the different stages of chemically induced hepatocarcinogenesis (HCC) and the occurring morphological changes. To provoke sustained oxidative stress and chronic inflammation, CF1 mice received dietary p -dimethylaminoazobenzene (DAB, 0.5%, w/w) during a whole period of 14 months. HO-1 expression increased along the experimental trial in morphologically normal hepatocytes in DAB-treated animals. HO-1 expression diminished in altered hepatic foci (AHF) and oval cells and early preneoplastic lesions. Otherwise, marked HO-1 overexpression was detected in Kupffer cells and macrophages surrounding necrotic and nodular areas. Adenomas showed decreased HO-1 immunostaining. In hepatocellular carcinomas, an inverse relationship was found between the immunohistochemical expression of HO-1 and the degree of tumour differentiation, being negative in poorly differentiated tumours. In our experimental model, down modulation of HO-1 expression correlated with malignancy progression. Thus, our data point to activation of HO-1 as a potential therapeutic tool. [source] Cell type accuracy of transthoracic fine needle aspiration material in primary lung cancerRESPIROLOGY, Issue 2 2001Adnan Yilmaz Objective: The aim of this study was to evaluate the diagnostic accuracy of transthoracic fine needle aspiration (TFNA) materials in establishing the specific cell type in primary lung cancer, and to study the influence of several factors on this accuracy. Methodology: The present study included 129 patients [(12 females, 117 males; mean age 54.6 years (range 25,75)] who underwent thoracotomy. The initial diagnosis was obtained by means of TFNA biopsy in all patients. Transthoracic fine needle aspiration was performed by 22-gauge Chiba needle with fluoroscopy guide in 93 patients and with computed tomography guide in 36 cases. Results: The overall concordance was 73.6% (Kappa = 0.52). The worst agreement was obtained for the large cell carcinoma (40%; Kappa = 0.48). The likelihood of a correct diagnosis using the TFNA specimens was 6.2-fold higher for well-differentiated tumours than for poorly differentiated tumours (P < 0.005). The stage of tumour and diameter of the lesion had no effect on cell agreement. Cell agreement was higher in central lesions than peripheral lesions, but the difference was not statistically significant (P = 0.097). This difference was more significant between patients with central and peripheral epidermoid carcinoma (P = 0.057). Conclusion: In our opinion, cell typing by TFNA may lead to incorrect results in the presence of poor differentiation, mixed tumours and peripheral epidermoid carcinomas. [source] Cholinergic switch associated with morphological differentiation in neuroblastoma,THE JOURNAL OF PATHOLOGY, Issue 4 2009Franck Bourdeaut Abstract The morphology of malignant cells distinguishes between undifferentiated, poorly differentiated and differentiating neuroblastomas and constitutes a strong prognostic factor. Spontaneous or treatment-induced maturation characterizes a subset of neuroblastomas. It constitutes the basis of retinoic acid treatment to improve survival in aggressive neuroblastomas. However, the molecular events that drive differentiation are poorly understood. In the present study we have investigated the relationships between gene expression profiles and differentiation criteria in stroma-poor neuroblastomas. This study included three undifferentiated (UN), 20 poorly differentiated (PDN) and 11 differentiating (DN) neuroblastomas. These groups could be clearly separated using unsupervised clustering methods, which further enabled a major classification impact of genes involved in neural development, differentiation and function to be identified. UNs are characterized by high ASCL1, high PHOX2B, low GATA2, low TH and low DBH expressions. Most PDNs harbour a clear adrenergic phenotype, even in the presence of missense PHOX2B mutations. Finally, all DN tumours demonstrate cholinergic features. Depending upon their association with adrenergic characteristics, this enables dual ,cholinergic/adrenergic' and ,fully cholinergic' neuroblastomas to be defined. This suggests that the cholinergic switch, a final specification process that occurs physiologically in a minority of sympathetic neurons, is a critical step of differentiation in some neuroblastic tumours. This switch is associated with a down regulation of DBH that is apparently not strictly dependent upon PHOX2B. Conversely, GATA2 and TFAP2B may play critical roles in maintaining adrenergic features in poorly differentiated tumours. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Expression of CD44s and CD44v6 in transitional cell carcinomas of the urinary bladder: comparison with tumour grade, proliferative activity and p53 immunoreactivity of tumour cells,APMIS, Issue 11 2007JITKA KUNCOVÁ Alterations of CD44 glycoproteins have been shown to play an important role in progression of various malignancies, including urothelial cancer. We investigated expression patterns of CD44s and CD44v6 in transitional cell carcinoma (TCC) of the urinary bladder in relation to tumour grade, proliferative activity, and immunoreactivity for p53. The selected markers were detected immunohistochemically in 122 samples of TCC. We found a close relationship between CD44s and CD44v6 expression and tumour grade. The extension of positive staining for CD44s and CD44v6 towards the luminal surface was a predominant feature of differentiated carcinomas (grades 1 and 2), suggesting deranged maturation of cancer cells related to their neoplastic transformation. Heterogeneous expression of CD44s and CD44v6 predominated in poorly differentiated tumours (G3,4). However, areas of squamous differentiation within the high-grade tumours displayed strong immunoreactivity for both CD44s and CD44v6. The proliferative activity and p53 overexpression increased with the dedifferentiation of the tumour. The results of this study are discussed in relation to the significance of CD44 expression in TCC and to the explanation for controversial results reported in previous studies on the relationship between CD44 expression and the biological behaviour of urothelial cells. [source] | ||||||||||