1,720,969 research outputs found
Electron microscopy: the gold standard in the differential diagnosis of chromophobe renal cell carcinoma and oncocytoma.
No full texto the Editors: We read the article “Classification and Reclassification of Adult Renal Epithelial Tumors,” by Mazzucchelli and colleagues,1 with great interest. The authors underlined that sometimes the differential diagnosis between chromophobe renal cell carcinoma and oncocytoma can be very difficult. Renal oncocytoma is always a benign lesion,2 while at other sites (salivary glands, thyroid, breast, etc.) it has a malignant counterpart. Consequently, conclusive diagnostic criteria must be acquired to diagnose renal oncocytoma definitively because the treatment should be conservative (wait and see or tumorectomy). Immunohistochemistry is not conclusive.3 Because ultrastructurally the oncocytes contain numerous mitochondria, the majority of which are of normal size and shape, the use of monoclonal antibody against human mitochondria should theoretically be conclusive in the diagnosis of the tumor. Unfortunately, chromophobe renal cell carcinoma also expresses this antibody, as do all the oncocytic lesions. This finding is in contrast to the ultrastructural characteristics of chromophobe renal cell carcinoma. In fact, the cytoplasm of neoplastic cells is crowded by loose glycogen deposits and numerous, sometimes invaginated vesicles (Table I). Therefore, electron microscopy is the gold standard for documenting oncocytic cell origin. In our experience this procedure may be used on formalin-fixed material and demonstrates that the oncocytes have rounded nuclei with compact nucleoli and numerous cytoplasmic mitochondria (Figure 1), while chromophobe renal cell carcinoma shows miocrovescicles in the cytoplasm (Figure 2). In conclusion, we think that electron microscopy on formalin-fixed material should be considered the choice procedure in the differential diagnosis of chromophobe renal cell carcinoma and oncocytoma
Resection of Congenital Cystic Intrapulmonary Lesions Is Always Necessary
No full textRecently we correlated histology and computed tomographic imaging of intrapulmonary congenital cystic lesions of the adult, including intrapulmonary cysts and congenital cystic adenomatoid malformation type I.
West and colleagues [1] described a carcinoma after a congenital lesion in a young patient. They underlined the possibility of underestimation of these lesions.
Then Lantuejoul and colleagues [2] confirmed the relation between carcinoma and this kind of congenital lesions in their study.
These two studies unequivocally demonstrate the carcinogenetic potential of type I congenital cystic adenomatoid malformation (CCAM).
This finding will radically modify the therapeutic approach to the congenital pulmonary cystic lesions in the adults.
Beside CCAM, other pulmonary cystic malformations are: congenital lobar emphysema, pulmonary sequestrions, bronchogenic cysts, and other foregut cysts, including intrapulmonary cysts [3].
The intrapulmonary bronchogenic cysts may be asymptomatic and are identified in the adult on routine imaging. All the other cystic malformations are symptomatic and found in the childhood.
In our recent experience when they are intrapulmonary lesions, the bronchogenic cysts are radiologically indistinguishable from large single CCAM type I. Only histologic examination can establish the cystic nature of the lesion. The presence of parietal cartilage islands, bronchial glands, smooth muscle, and occasionally calcifications and ossification is conclusive for intrapulmonary bronchogenic cysts in the differential diagnosis with CCAM type I [4].
Because the differential diagnosis between solitary IBC and type 1 CCAM is not possible by radiologic procedures, generally a complete surgical resection is advisable in solitary cystic congenital intrapulmonary lesions in adults at the time of diagnosis, even if asymptomatic. A delayed or incomplete resection may expose the patient to tumour development in the case of type 1 CCAM
Oncocytic sialolipoma of the submandibular gland with sebaceous differentiation: A new pathological entity
No full textCase Report: We report the case of an oncocytic sialolipoma of the submandibular gland with sebaceous differentiation in a 73-year-old man. The initial symptom was a right submandibular painless mass. Ultrasonography showed a hypoechoic oval mass posterior to the submandibular gland. The tumorectomy was performed with preservation of the salivary gland. The tumor was composed of mature adipose tissue surrounded by a thin fibrous capsule, multiple nodules of oncocytes, normal ductal-acinar units with focal ductal sebaceous differentiation. Discussion: We reviewed literature of the reported cases of mixed tumors of the salivary glands composed of mature adipose tissue with oncocytosis, salivary ducts, and acini with sebaceous differentiation. Conclusions: Sialolipoma and lipoadenoma with or without oncocytosis and/or sebaceous differentiation should be considered organ-specific tumors with a distinct histological appearance and specific terminology
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
