摘要:

DNA microarray technology is revolutionizing the way fundamental biologic questions are addressed in the postgenomic era. In this study by Hedenfalk et al., the authors attempted to identify discrete gene expression profiles for patients with known hereditary breast cancers caused by mutations inBRCA1andBRCA2, both of which increase the lifetime risk of developing breast cancer. The genome-wide perspective identified discrete sets of genes that discriminated betweenBRCA, BRCA2,and sporadic breast tumors. This commentary discusses some limitations of studying a small number of cases. The authors also address the need for validation on independent tumor sets, and the potential benefit of multivariable-type analyses to consider other potential confounding factors such as tumor grade, receptor status, tumor stage, and treatment information.

ISSN:1072-4109    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Ret proto-oncogene rearrangements are common in papillary thyroid carcinoma. The relationship of hyalinizing trabecular tumors (HTT) to papillary thyroid carcinoma (PTC) was analyzed in a recent report in which the presence of RET rearrangements was detected by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry in several HTT. This commentary examines this report and related studies in the literature emphasizing the limitations of these approaches and the practical implications of these findings.

ISSN:1072-4109    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Since its first description more than four decades ago, the atypical endometrial change associated with chorionic tissue effect has been widely confirmed in the literature. However, errors and inaccuracies in text books and other publications often occur. This review clarifies some of these misconceptions and presents a summary of new data on the histologic and immunohistochemical characteristics of the change. A brief discussion of the pathogenesis and biologic significance of the alteration is included.

ISSN:1072-4109    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Infiltrative astrocytic neoplasms are the most common malignancies of the central nervous system. They remain clinically problematic because of their involvement of brain structures critical to proper cognitive, behavioral, and motor function; their widely invasive properties, which make them difficult to resect totally; and their nearly inevitable biologic progression in spite of adjuvant therapy. Glioblastoma multiforme (GBM, World Health Organization grade IV), the most malignant form of infiltrating astrocytoma, can present as a high-grade lesion from the outset (so-called de novo GBM) or can evolve from a lower grade precursor lesion (secondary GBM). Molecular genetic investigations suggest that GBM is best regarded as a clinicopathologic entity composed of multiple molecular genetic subsets. Molecular alterations associated with progression to GBM and that define genetic subsets include epidermal growth factor receptor amplifications, p53 mutations, retinoblastoma pathway alterations [most commonly, p16(CDKN2A) losses], and chromosome 10 alterations, including PTEN mutations. Despite the wide range of genetic events that ultimately lead to GBM, the vascular changes that evolve are remarkably similar. Microvascular hyperplasia is spatially and temporally associated with pseudopalisading necrosis in GBM and is believed to be driven by hypoxia-induced expression of proangiogenic cytokines such vascular endothelial growth factor. In addition, genetic alterations in GBM are thought to contribute directly or indirectly to angiogenic dysregulation. Both p53 mutations and genetic losses on chromosome 10 may tip the balance toward an angiogenic phenotype through upregulation of proangiogenic factors and/or downregulation of angiogenesis inhibitors. Understanding genetic events and their relation to angiogenic regulation in astrocytic neoplasms may eventually lead to therapies that are specifically directed at molecularly defined subsets of these diseases.

ISSN:1072-4109    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Nonalcoholic fatty liver disease (NAFD) comprises a spectrum of conditions characterized by the presence of predominantly macrovesicular fatty change in the liver and the absence of alcohol consumption in amounts considered detrimental to the liver. The histologic spectrum of NAFLD includes fatty liver alone or steatohepatitis (NASH). Nonalcoholic steatohepatitis is associated with increasing fibrosis is some cases and may progress to cirrhosis. Nonalcoholic fatty liver disease is often associated with insulin resistance. It is likely that there are one or more additional pathophysiologic defects in those with NASH, rendering them more susceptible to injury from oxidative stress. The clinical and histologic features of NASH are described, and an approach to the diagnosis and treatment of NAFLD is provided.

ISSN:1072-4109    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Utilizing abrasive, exfoliative, and fine-needle aspiration techniques to diagnose infectious organisms by cytopathologic means is common practice. The increase in the number of immunosuppressed patients in conjunction with the relative ease with which specimens are procured has resulted in the need for rapid interpretation to ensure prompt and adequate treatment. Although some organisms cannot be definitively classified on cytologic preparations, morphologic clues that can guide the pathologist toward rendering a diagnosis helpful to clinicians are often present. In addition, some fungi and parasites rarely identified in cytopathology in the past are more frequently found in cytologic specimens today. This review focuses on organisms found in the United States. Special attention is paid to the morphologic findings on routine Papanicolaou- and Diff Quik–stained cytologic preparations and readily available special stains.

ISSN:1072-4109    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

CD 117 (KIT) is a transmembrane, tyrosine kinase growth factor receptor which is expressed on numerous diverse fetal and adult cells including hematopoietic cells, mast cells, melanocytes, germ cells, and the interstitial cells of Cajal. Its expression in tumors is also diverse, but with selective use and attention to specific staining patterns, this marker is useful in the identification of gastrointestinal stromal tumors, mast cell tumors, and seminomatous germ cell tumors.

ISSN:1072-4109    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:2002

数据来源: OVID