摘要:

Summary:Genetic, immunohistochemical, and histologic data has led to the reclassification of renal cell carcinoma in the last decade. Recent studies suggest that renal cell carcinomas in children and young adults may represent a distinct group of tumors. These tumors have unique genetic findings (most commonly t(x;1)(p11;q21)), a predominantly papillary architecture, numerous calcifications, granular cytoplasm, and a possible relationship with neuroblastoma.

ISSN:1072-4109    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Summary:Parachordoma is a very rare peripheral soft tissue tumor of unknown lineage, which has been described under other names, all of which imply a similarity to chordoma. It forms a circumscribed firm tumor, usually in deep soft tissue, with a variety of histologic patterns and cytologic features, including cords and nests of cells, some of which are vacuolated. The ultrastructure and immunophenotype indicate epithelial differentiation and parachordomas are additionally S‐100 protein positive. This tumor is distinct from extraskeletal myxoid chondrosarcoma and probably from soft tissue myoepithelioma. While histologically it somewhat resembles chordoma, parachordoma has a wider range of appearances, and the two neoplasms differ in their detailed cytokeratin immunophenotype and their clinical behavior. Parachordoma is a slowly growing tumor with occasional late recurrence; cases with reported metastasis have not been histologically convincing. This commentary discusses the terminology, origin, and possible nature of this enigmatic neoplasm.

ISSN:1072-4109    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Summary:Approximately 25% of patients with stage I (node negative) breast cancer relapse at a rate similar to those with stage II disease. Inadvertent pathologic “under‐staging” of lymph node status is one plausible explanation for this phenomenon. While many studies have shown that additional sectioning +/− immunohistochemical staining for epithelial markers increases the rate of detection of small deposits of metastatic carcinoma, few have had sufficient statistical power to examine the impact of “occult” metastasis on clinical outcome. This provocative update by the International Ludwig Breast Cancer Study Group provides support for considering going “the extra mile” to detect lymph node metastasis in postmenopausal patients and those with the lobular subtype of invasive breast cancer.

ISSN:1072-4109    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Summary:Grading schemes for meningiomas have traditionally designated tumors as “meningioma,” “atypical meningioma,” or “anaplastic (malignant) meningioma,” depending upon the presence of histopathologic features thought to indicate aggressive behavior. In the past, most systems have considered brain invasion by tumor as the best evidence of malignancy. Perry et al. have recently investigated the significance brain invasion as a prognostic feature in meningiomas. The authors studied a series of 116 patients who had been diagnosed previously with “malignant meningioma” due to the presence of brain invasion, histologic anaplasia, or metastasis. On the basis of a multivariate analysis of histopathologic features and their relationship to tumor recurrence and patient survival, the authors concluded that brain invasion should be considered one of the diagnostic features of atypical meningioma. Accordingly, the diagnosis of malignant meningioma should be reserved for those tumors that are frankly anaplastic and/or contain (≥20 mitoses per 10 high‐power fields (HPF). Due in large part to the strength of evidence in this study, the World Health Organization (WHO) has adopted a grading scheme for meningiomas that incorporates many of the authors' proposals. New diagnostic criteria will result in improved reproducibility with fewer diagnoses of malignant meningioma (WHO grade III).

ISSN:1072-4109    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Summary:HER‐2/neu (also known as c‐erbB‐2) oncogene is a member of the epidermal growth factor receptor family and its amplification is one of the most common genetic alterations associated with human breast cancer. Preclinical studies have suggested that HER‐2/neu overexpression enhances metastatic potential of breast cancer cells. Although some discrepancies exist in clinical studies, in general, HER‐2/neu amplification is found to be associated with more aggressive clinicopathologic features. HER‐2/neu amplification is also associated with drug resistance or sensitivity to specific chemotherapy and hormonal therapy regimens. Advances in breast cancer therapies in recent years have moved towards the development of tumor‐specific targeted therapies. Monoclonal antibodies directed against HER‐2/neu have been developed and used in clinical practice. These developments necessitate a reliable assay for assessment of HER‐2/neu. This article is a review of biologic and clinical significance of HER‐2/neu and summarizes HER‐2/neu detection methods.

ISSN:1072-4109    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Summary:Mucosal melanomas, far fewer in number than melanomas of the skin, manifest a far more aggressive and more rapid life‐consuming biologic course. This behavior attends melanomas at any mucosal site, upper aerodigestive tracts, anorectum, and male and female genital tracts. Prognostic factors for both groups of melanoma are similar, but most mucosal melanomas have reached the dangerous limits, e.g., depth of invasion or thickness of melanoma at the time of diagnosis. In general, the mucosal melanomas are also more refractory to therapeutic modalities. In part, this may be due to anatomic restrictions of site and the large size of tumor when first discovered. This review presents a contemporary assessment of melanomas at all of the major mucosal sites.

ISSN:1072-4109    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Summary:The term malignant rhabdoid tumor (MRT) has been used to describe a heterogeneous group of neoplasms, having in common distinct so‐called “rhabdoid” cytologic features. The recent discovery of a candidate tumor suppressor gene for MRT, INI1 on chromosome (Ch)22q11.2, has re‐established this neoplasm as a distinct entity. Malignant rhabdoid tumor may arise either de novo from nonneoplastic cells or through tumor progression from other types of neoplasms. These latter tumors, in which other nonrhabdoid tumor components are identified, may be termed composite MRT. In order to avoid misdiagnosing MRT as other types of neoplasia, one must keep in mind three distinct clinicopathologic features—young age of onset, variable histologic and immunohistochemical patterns, and an aggressive infiltrative character. In difficult cases, cytogenetics, fluorescence in situ hybridization (FISH), and molecular genetic analysis may assist in diagnosing MRT.

ISSN:1072-4109    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:2000

数据来源: OVID