1,720,969 research outputs found
Perivascular epithelioid cell tumor (PEComa) in the genitourinary tract
No full textPerivascular epithelioid cell tumors (PEComas) are mesenchymal tumors composed of histologically, immunohistochemically, ultrastructurally, and genetically distinctive cells. PEComas have been described in different organs and are considered ubiquitous tumors. In this review we discuss recent informations related to PEComas in the genitourinary tract
Risk of neoplastic transformation in asymptomatic radial scar. Analysis of 117 cases
No full textBACKGROUND: Radial scar (RS) is a benign breast lesion but a variable percentage of cases are associated with atypical epithelial proliferations and cancer. Previous studies have shown that patient age and the size of RS are correlated to a potential neoplastic transformation. METHOD: We collected 117 asymptomatic patients with suspected RS following a mammogram, histologically confirmed. The clinical, pathological and immunophenotypical analysis is reported. The cases are subdivided into three different groups: (1) RS "Pure", without epithelial atypia; (2) RS associated with epithelial atypical hyperplasia; (3) RS with cancer. RESULTS: "Pure" RS was detected in 55 patients (47\%); the mean age was 48.1 years and the mean size 0.94 cm. RS associated with atypical epithelial hyperplasia was identified in 25 cases (21\%) with a mean age of 53.1 years and a mean size of 0.98 cm. Carcinoma in RS was observed in 37 cases (32\%); the mean age was 55.5 years and the mean size was 1.16 cm. The mean age was statistically significant (P = 0.004) in separating RS with cancer from the two other RS groups. The size of RS was not sufficiently statistically significant (P = 0.2) to differentiate the risk. Atypical lesions and cancers showed a morphology and marker of low-grade aggressiveness. CONCLUSION: RS seems to represent a natural model of carcinogenesis starting from a proliferative lesion in patients of less than 50 years of age and developing into an atypical and later into a carcinomatous lesion. The fact that most carcinomas arising in RS are low grade also favors this hypothesis. All RS should be excised
PEComas: the past, the present and the future
No full textThe perivascular epithelioid cell (PEC) is a cell type constantly present in a group of tumors called PEComas. PEC expresses myogenic and melanocytic markers, such as HMB45 and actin. Recently, recurrent chromosomal alterations have been demonstrated in PEC. At present, PEComa is a widely accepted entity. In the past 10 years, the use of this term has allowed to report and describe numerous cases permitting to start highlighting the biology of this group of lesions. PEComas are related to the genetic alterations of tuberous sclerosis complex (TSC), an autosomal dominant genetic disease due to losses of TSC1 (9q34) or TSC2 (16p13.3) genes which seem to have a role in the regulation of the Rheb/mTOR/p70S6K pathway. There are some open questions about PEComas regarding its histogenesis, the definition of epithelioid angiomyolipoma and the identification of the histological criteria of malignancy. An innovative therapeutic trial using rapamycin is under way for tumors occurring in TSC such as renal angiomyolipoma and lymphangioleiomyomatosis. Its success could provide the rationale for the use of the same drug in other lesions composed of PECs, especially in the malignant ones
Molecular pathology of lymphangioleiomyomatosis and other perivascular epithelioid cell tumors
No full textCONTEXT: Lymphangioleiomyomatosis (LAM) is a cystic lung disease that can be included in the wide group of proliferative lesions named PEComas (perivascular epithelioid cell tumors). These proliferative tumors are characterized by the coexpression of myogenic and melanogenesis-related markers. In all these lesions, genetic alterations related to the tuberous sclerosis complex (TSC) have been demonstrated. Striking improvements in the understanding of the genetic basis of this autosomal dominant genetic disease are coupled to the understanding of the mechanisms that link the loss of TSC1 (9q34) or TSC2 (16p13.3) genes with the regulation of the Rheb/m-TOR/p70S6K pathway. These data have opened a new era in the comprehension of the pathogenesis of LAM and have also suggested new therapeutic strategies for this potentially lethal disease. OBJECTIVE: To present and discuss the pathologic and molecular features of LAM within the spectrum of PEComas, providing a rational approach to their diagnosis. DATA SOURCES: The published literature and personal experience. CONCLUSIONS: The inclusion of LAM within the PEComa category is supported by a variety of biologic data and can significantly help in providing a comprehensive view of this interesting and clinically relevant group of lesions. The demonstration of molecular alterations of the mTOR pathway in LAM and other PEComas represents a rational basis for innovative therapeutic approaches with inhibitors of mTOR signalin
Cancer Size, Histotype, and Cellular Grade May Limit the Success of Fine-Needle Aspiration Cytology for Screen-Detected Breast Carcinoma
No full textBACKGROUND: Fine-needle aspiration cytology (FNAC) was adopted as the first-line method to assess breast lesions in the Verona Breast Cancer Screening Program. The radiological and pathological factors relating to the success of FNAC in breast cancer series were evaluated. METHODS: Between July 1999 and June 2004, 418 breast cancers were submitted to FNAC in the Verona Breast Cancer Screening Program. The results of FNAC diagnoses were compared with final histology. The FNAC sensitivity rate, underestimation of malignancy rate, and inadequacy rate were correlated with histotype, size, grading, and radiologic imaging. RESULTS: Of the 418 cancers, 95 were in situ, and 323 were invasive. The sensitivity rate was higher in invasive cancers (P < .001), and the underestimation of malignancy rate was greater in in situ cancers (P = .002). Lobular type cancers had a lower sensitivity rate in invasive and in situ cancers. The sensitivity rate was 100% in medullary, mucinous, and papi! llary cancers, and no case had inadequate sampling. The underestimation of malignancy rate was higher in tubular carcinoma (18.2%); lobular carcinoma showed a higher inadequacy rate (10.4%). The sensitivity rate was lower and the underestimation of malignancy rate was higher in low-grade carcinomas and in lesions <1 cm (P < .001). The performance of FNAC was not significantly influenced by mammographic imaging of lesions. CONCLUSIONS: Low-grade cancer histotype, cancer size <1 cm, and lobular and tubular histotypes limit the possibility of obtaining positive results by FNAC. Operator experience and multidisciplinary consultation may help in overcoming these limitations. Pathologists must be aware of the limits of FNAC; results must be critically evaluated in light of the triple assessment. Cancer (Cancer Cytopathol) 2009;117:491-9. (C) 2009 American Cancer Society
HER-2/neu assessment in breast cancer using the original FDA and new ASCO/CAP guideline recommendations: impact on selecting patients for herceptin therapy
No full textWe evaluated HER-2/neu status in 100 consecutive ductal breast carcinomas by using the Food and Drug Administration (FDA) and American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) scoring systems. With the FDA system, scores were 3+ in 23.0\%, 2+ in 25.0\%, and 0 or 1+ in 52.0\% of cases. With the ASCO/CAP system, scores were 3+ in 16.0\%, 2+ in 34.0\%, and 0 or 1+ in 50.0\%. With the FDA and ASCO/CAP systems, respectively, 3+ cases (n = 23 and 16, respectively) showed high-grade, granular HER-2/neu amplification in 15 (65\%) and 14 (88\%); low-grade, borderline amplification in 7 (30\%) and 1 (6\%); and chromosome 17 polysomy without amplification in 1 (4\%) and 1 (6\%).Concordance between schemes was higher for cases with high-grade, granular HER-2/neu amplification (concordance coefficient, 0.74). Cases with low-grade, borderline HER-2/neu amplification showed poor concordance (concordance coefficient, 0.20).The FDA and ASCO/CAP schemes for HER-2/neu evaluation select patients differently for trastuzumab therapy. Major discordance is present for low-grade, borderline HER-2/neu amplification. FDA low-grade, borderline tumors would be reclassified as without HER-2/neu amplification or as polysomic. The ASCO/CAP scheme has a great concordance coefficient between strong 3+ immunohistochemical cases and cases with high-grade, granular HER-2/neu amplification
Is there still a role for fine-needle aspiration cytology in breast cancer screening? Experience of the Verona Mammographic Breast Cancer Screening Program with real-time integrated radiopathologic activity (1999-2004).
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Tasso di inadeguatezza della citologia agoaspirativa con ago sottile (FNAC) di masse superficiali e profonde nell'ambito di un'attività diagnostica integrata cito-radiologica
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