1,721,418 research outputs found
Sinonasal tumor pathology: what's new?
No full textThe sinonasal tract is an anatomical region affected by a wide variety of tumors with different clinical behavior, histologic and molecular features. Substantial advances have been made in the field of sinonasal tumor pathology in recent years, including improvement in the diagnosis, treatment and genetic characterization. In this article, a review of the histological features of new distinctive pathologic entities as well as newly described molecular alterations of these rare tumors is presented
Epidemiology and classification of bone tumors
Full text linkPrimary bone tumors are uncommon and this has certainly contributed to the scarcity of data about their relative frequency,and to the limited understanding of the risk factors.
Overall, bone sarcomas account for 0.2% of all malignancies, and the adjusted incidence rate for all bone and joint malignancies is 0.9 per 100,000 persons per year, while the 5-year overall survival rate is 67.9%. The age specific incidence rates of bone sarcomas show a bimodal distribution, with a first peak occurring in the second decade, and a second peak occurring in patients older than sixty, in relation with the age distribution of the main histological subtypes. Several bone tumor types occur in the setting of inherited syndromes, while some other develop in association with non-neoplastic precursors or in the setting of previous benign tumors. In recent years, significant advances have occurred in the molecular and cytogenetic characterization of benign and malignant bone tumors. The detection of clonal chromosomal aberrations, specific molecular genetic changes, and the identification of growth related tumor cell signaling pathways have resulted in a better understanding of the pathogenesis of several neoplastic entities, and have provided the basis for an improvement in the diagnostic workup and differential diagnosis of several bone tumors presenting with overlapping clinical, radiological and pathological features, as well as for the identification of new prognostic factors and therapeutic target
An Update on Sinonasal Round Cell Undifferentiated Tumors
No full textThe sinonasal cavities host a wide variety of undifferentiated malignancies with round cell morphology, including neoplasms of epithelial, mesenchymal, neuroectodermal, and hematolymphoid lineage. The differential diagnosis may be difficult, especially in small biopsy material, due to overlapping morphology, but their correct classification is clinically relevant. The aim of this review is to provide practical guidelines for the differential diagnosis of these malignancies, with emphasis on recently described entities and special reference to the role of ancillary techniques
Tenascin expression in cutaneous fibrohistiocytic tumors: Immunohistochemical investigation of 24 cases
No full textGranulation tissue-like spindle cell (sarcomatoid) carcinoma of the head and neck: a deceptively bland-looking underdiagnosed malignancy
Full text linkThe diagnosis of head and neck spindle cell squamous carcinoma (SC-SCC) is often challenging. Lesions with a prominent inflammatory infiltrate and reactive vessels may have a granulation tissue-like appearance, therefore being difficult to distinguish from reactive lesions, like contact ulcers, post-intubation granulomas, inflammatory pseudotumors, or benign vascular lesions. In this study, we analyzed the clinicopathological features of a series of 17 head and neck SC-SCC with granulation tissue-like appearance. All patients, but two, were males, ranging in age between 57 and 80 years. The larynx was the most frequently affected site (n = 12), followed by the tongue (n = 4). One tumor was hypopharyngeal. Most consult cases were submitted with benign suggestion or because of unexpected recurrences of granulation tissue polyps. Histologically, all lesions consisted of an ulcerated polypoid proliferation of moderately to markedly atypical spindle cells, with a minor component of conventional invasive or in situ squamous carcinoma. At least one cytokeratin cocktail was positive in 13 cases. The staining was limited to a few neoplastic cells in most cases. Positivity for p63, p40, and cytokeratins 5/6 was detected only in the conventional squamous cell carcinoma component, when present. ALK1 was negative in all cases. Sixteen cases were tested for p53 and all showed aberrant expression (12 diffusely positive and 4 of null-phenotype). The diagnosis of granulation tissue-like SC-SCC is challenging due to the close clinical and histological overlap with several benign conditions. Since the expression of epithelial markers is limited, the use of an immunohistochemical panel including p53 is recommended
The contribution of electron microscopy to the characterization of soft tissue fibrosarcomas
No full textIn recent years, with the application of immunohistochemical and cytogenetic methods, numerous lesions formerly diagnosed as fibrosarcoma were reclassified as other malignant soft tissue tumors, and therefore conventional fibrosarcoma has largely become a diagnosis of exclusion. On the other hand, several new entities belonging to the group of fibrosarcomas have been characterized, including low-grade fibromyxoid sarcoma / hyalinizing spindle cell tumor with giant rosettes, sclerosing epithelioid fibrosarcoma, acral myxoinflammatory fibroblastic sarcoma, and the epithelioid variant of myxofibrosarcoma. Electron microscopy has contributed to the identification of the fibroblastic phenotype in these fibrosarcoma variants and still retains a central role in the differential diagnosis of these soft tissue sarcomas, thus helping to render specific diagnoses and to broaden the spectrum of fibrosarcoma variants. © 2013 Informa Healthcare USA, Inc
Recognising hidden phenotypes in sarcomas through the electron microscope
No full textDifferentiation along a distinct cell lineage can be identified either morphologically or with the adjunct of different ancillary techniques. While immunohistochemistry has progressively supplanted electron microscopy as the method of choice to characterize the phenotype of neoplastic cells in soft tissue tumors and in solving most differential diagnoses, a number of lesions still lack reliable specific markers or show overlapping antigen expression, which can be categorized by ultrastructural analysis through the recognition of submicroscopic features indicative of a specific line of differentiation. This review discusses the role of electron microscopy in the identification of the phenotype of neoplastic cells in soft tissue sarcomas, with particular reference to the diagnostic aspects. Sarcomas in which the cellular phenotype that can be better recognized by electron microscopy include those belonging to the fibroblastic/myofibroblastic group, particularly those displaying a poorly differentiated/pleomorphic morphology. Occasionally, in tumors with smooth muscle, skeletal muscle, adipocytic, vascular endothelial, and Schwann cell differentiation electron microscopy may help in the differential diagnosis
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