1,720,968 research outputs found
Adenoid (acantholytic) squamous cell carcinoma of the skin.
No full textCutaneous adenoid squamous carcinoma (ASCC) is a distinctive neoplasm featuring tumor cell acantholysis. Because this lesion occasionally may prove troublesome diagnostically, we studied the clinical, histologic, and immunohistochemical features of 55 examples in order to further elucidate its characteristics. ASCC most often occurred in the skin of the head and neck in elderly patients. Of 49 patients in this series, 46 were men and 3 were women; their ages at diagnosis ranged from 25 to 90 yr, with a mean of 71. Six individuals had 2 metachronous neoplasms. ASCC generally behaved in an indolent manner, although 19\% of cases did metastasize widely and prove fatal. Tumor size of greater than 1.5 cm appeared to correlate with the risk of an adverse clinical outcome. In addition, 10 patients with ASCC of the skin subsequently developed visceral malignancies. The cutaneous neoplasms were typified by invasive, tubular or pseudoglandular profiles of polygonal cells in the dermis, with glassy eosinophilic cytoplasm and focal squamous pearl formation. Connections to the overlying epidermis were commonly apparent. Immunohistochemically, ASCC demonstrated uniform reactivity for cytokeratin, but lacked markers of specialized glandular cells. These findings militate against the interpretation that such tumors demonstrate partial adnexal differentiation, and show that immunohistology may prove helpful in the differential diagnosis between ASCC and primary or metastatic adenocarcinomas of the skin
Hemangiopericytoma: histopathological pattern or clinicopathologic entity?
No full textThe tumor designated by Stout and Murray as "hemangiopericytoma" (HPC) more than 50 years ago continues to represent a source of uncertainty and disagreement among pathologists. In particular, questions exist regarding the synonymity of a hemangiopericytomatous growth pattern--defined by a monomorphic population of compact polygonal or bluntly fusiform cells and a branching stromal vascular pattern with a "staghorn" configuration--and the presence of a reproducible biological entity. It has been shown repeatedly that these same histologic features may be observed at least focally in a diversity of neoplasms, including "true" hemangiopericytomas, synovial sarcomas, mesenchymal chondrosarcomas, infantile fibrosarcomas, malignant fibrous histiocytomas, malignant peripheral nerve sheath tumors, leiomyosarcomas, endometrial stromal sarcomas, solitary fibrous tumors, myofibromas, malignant mesotheliomas, thymomas, sarcomatoid carcinomas, malignant melanomas, and "phosphaturic mesenchymal tumors." Despite their potential sharing of the microscopic attributes in question, such neoplasms have individualistic clinical features and can also be distinguished from one another by specialized pathologic analyses. HPC is "defined" in that context by reactivity for vimentin, with or without CD34 and CD57, but it lacks other immunodeterminants of epithelial, neural, and myogenous differentiation. Paradoxically, this phenotype is indeed associated with the presence of myogenous-type cytoplasmic filaments in ultrastructural evaluations of HPC. Other lesions that may resemble "true" HPC--but which possess dissimilar subcellular and clinical characteristics--include solitary fibrous tumors, hemangiopericytomalike tumors of the sinonasal tract, and "infantile (congenital) hemangiopericytomas." Such observations suggest that the hemangiopericytoma is both a pathologic entity and a morphological pattern, and they emphasize the utility of adjuvant pathologic studies in this diagnostic context
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
Pseudovascular adenoid squamous cell carcinoma of the skin. A neoplasm that may be mistaken for angiosarcoma.
No full textThe adenoid variant of squamous cell carcinoma has been well-documented in several anatomic sites, including the skin. This tumor is characterized by acantholytic arrays of neoplastic keratinocytes that form pseudoglandular profiles. Although it is typically confused with adenocarcinomas, adenoid squamous cell carcinoma also may be mistaken for malignant vascular proliferations. This report concerns six acantholytic cutaneous squamous cell carcinomas that closely simulated angiosarcomas on conventional histologic examination. They arose in sun-exposed skin areas in middle-aged or elderly patients (mean age, 60 years), five of whom were men. In contrast to the typical clinical appearance of angiosarcoma, pseudovascular adenoid squamous cell carcinoma presented itself as a discrete cutaneous ulcer or crusted tanpink nodule. Microscopically, this lesion was characterized by interanastomosing cordlike arrays of polygonal or flattened tumor cells, with internal pseudolumina that contained detached tumor cells. A connection between the dermal neoplasm and the epidermis was apparent in three cases, but it was focal. Erythrocytes were seen in pseudovascular spaces in five tumors. Immunohistochemically, all examples of pseudovascular adenoid squamous carcinoma were reactive with antibodies to cytokeratin and epithelial membrane antigen (EMA). In addition, three expressed vimentin, two exhibited blood group antigen-positivity, and two bound Ulex europaeus I agglutinin. None of them was immunoreactive for Factor VIII-related antigen, and two of three studied for CD34-reactivity were likewise negative. A control group of six cutaneous angiosarcomas was uniformly nonreactive for cytokeratin and EMA, but they showed positivity for vimentin, Ulex binding, and CD34 positivity in all instances. Pseudovascular adenoid squamous cell carcinoma may be distinguished effectively from angiosarcoma of the skin by attention to its clinical features and by appropriate immunohistochemical studies. These two tumors differ in biologic behavior; three patients with pseudovascular adenoid squamous cell carcinoma died of their tumors, whereas all angiosarcomas in this series proved fatal
Undifferentiated small round-cell tumors of childhood: the immunocytochemical demonstration of myogenic differentiation in fine-needle aspirates.
No full textThe recognition of myogenic differentiation is not always possible using routine light or electron microscopic techniques. In this article, we describe our experience with two small round-cell neoplasms occurring in young children, each of which exhibited an undifferentiated light microscopic appearance. In both cases, myogenic features were revealed by immunocytochemical methods applied to fine-needle aspiration (FNA) biopsies. Each was immunoreactive for desmin and vimentin and failed to react with antibodies to leukocyte-common antigen. Moreover, formalin-fixed tissue sections of one case were negative for cytokeratin and epithelial membrane antigen. Sporadic reactivity for neuron-specific enolase and Leu-7 antigen was observed in occasional cells in FNA specimens, but synaptophysin was not identified. The rapidity of the method and the reliability of the immunocytochemical findings, when compared with routine cytologic evaluation, emphasize the diagnostic utility of immunocytochemical analysis when FNAs of pediatric soft-tissue tumors are obtained
Gross cystic disease fluid protein-15 in salivary gland tumors.
No full textGross cystic disease fluid protein-15 (GCDFP-15) is a 15-kd glycoprotein that is expressed by normal apocrine epithelia and in a majority of breast carcinomas. However, recent studies have demonstrated that this substance is also present in tumors of the salivary glands, sweat glands, and prostate gland. To determine whether the expression of CGDFP-15 might aid in the differential diagnosis of salivary gland lesions, the anti-GCDFP-15 monoclonal antibody D6 was applied to paraffin sections of 133 such neoplasms. Benign tumors (76\% reactive) were more often labeled than malignant lesions (28\% reactive) by this antibody; overall, 53 (41\%) of 133 cases were positive for GCDFP-15. Notably, the tubuloglandular components in 17 (81\%) of 21 pleomorphic adenomas were reactive, but no example of either adenoid cystic carcinoma or polymorphous low-grade adenocarcinoma were labeled. In contrast, 24\% of adenocarcinomas stained with this antibody. The apparent expression of GCDFP-15 by a spectrum of salivary gland tumors supports their biologic relationship to lesions of the cutaneous apocrine glands and breast. Furthermore, the demonstration of this determinant may be of use in suggesting the salivary gland nature of poorly differentiated carcinomas of the head and neck, and it may facilitate the separation of pleomorphic adenoma from histologically similar malignant neoplasms in the salivary glands themselves
Classical and cellular (atypical) congenital mesoblastic nephroma: a clinicopathologic, ultrastructural, immunohistochemical, and flow cytometric study.
No full textSixteen cases of congenital mesoblastic nephroma (CMN) were studied. The tumors showed variable patterns of growth, degrees of cellularity, and mitotic activity. Six tumors had the classical pattern of CMN, seven were of the cellular or atypical variant and three showed combined features. The mean ages at presentation were 16 days, 5.3 months, and 2.3 months, respectively. Average size and weight were 5.1 cm and 94 g for classical CMN, 9.1 cm and 620 g for cellular CMN and 10.5 cm and 150 g for combined tumors. Cyst formation, hemorrhage and necrosis were confined to cellular CMNs and to cellular areas of combined CMNs. Mitotic activity ranged from 0 to 1/10 high-power fields (HPFs) in classical tumors to 25 to 30/10 HPFs in cellular tumors. Clear cell sarcoma-like areas were observed in three neoplasms. In ten cases there was invasion of perirenal fat; in one case each, invasion of the psoas muscle, renal vein wall, and renal vein lumen was observed. Ultrastructural and immunohistochemical studies showed features consistent with myofibroblastic differentiation. Flow cytometric analysis revealed euploidy in one classic CMN, one cellular CMN and in classic areas of a combined CMN; cellular areas of the latter tumor were aneuploid. All patients with follow-up were alive without evidence of disease after a mean period of 5 years following nephrectomy alone. No correlation was observed between the pathologic features assessed and the biologic behavior of these neoplasms
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
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