摘要:

Summary:Various cervical lesions at times may be difficult to distinguish from one another on routine hematoxylin and eosin stains, and immunostaining for the proliferation-associated antigen Ki-67, using monoclonal antibody MIB-1, can aid their distinction. The reduced MIB-1 expression in atrophy and increased MIB-1 expression in dysplasia permits easy distinction between these conditions. Presence of MIB-1 in more than 15% of basal cells and/or in surface half of the epithelium favor a diagnosis of condyloma over squamous metaplasia or inflammatory changes. Normal endocervix shows MIB-1 positivity in less than 10% of the cells, but usually in more than 20% of cells in cervical adenocarcinoma. With increasing grade of dysplasia, the percentage of MIB-1 positive cells is increased, and positive cells are seen in the higher levels of the epithelium. Presence of more than 20% MIB-1 positive cells in Pap smears showing atypical cells of uncertain significance is associated with a diagnosis of dysplasia on subsequent biopsies. Cauterized tissues with dysplasia show MIB-1 expression similar to adjacent noncauterized dysplastic areas. MIB-1 expression is, therefore, useful in evaluating various cervical lesions.

ISSN:1072-4109    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:The histogenesis of granular cell tumor (GCT) has been a source of controversy since its recognition as an entity by Abrikossoff in 1926. These lesions can occur in virtually any location. Benign GCTs are not uncommon, but malignant ones are rare and at times difficult to diagnose. The main morphologic feature is the granularity of the cytoplasm which is caused by a massive accumulation of lysosomes. Early suggestions that GCT may have a myoblastic origin have been discounted and use of the term granular cell myoblastoma as a designation for this tumor is discouraged. Although most investigators currently favor a Schwann cell derivation based on immunohistochemical and electron microscopic findings and advocate the designation of granular cell schwannoma, some differences exist between schwannomas and GCTs in their ultrastructural characteristics and the expression of some immunohistochemical markers. Other investigators believe that GCT is not a specific entity but rather a degenerative change that can occur not only in Schwann cells but also in a variety of other normal and neoplastic cells. Until more information becomes available, particularly that derived from cytogenetic studies, this lesion should be considered a separate entity and the descriptive designation of granular cell tumor continues to be appropriate.

ISSN:1072-4109    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:Skeletal myxoid chondrosarcoma is a histologic variant of conventional skeletal myxoid chondrosarcoma, whereas extraskeletal myxoid chondrosarcoma is a distinct entity characterized by a reciprocal t(9;22) translocation resulting in fusion of theEWSandCHNgenes. Rarely, extraskeletal myxoid chondrosarcoma can occur in bone, and it is difficult to describe such tumors, unambiguously, using the present nomenclature. Designation as “chordoid sarcoma of bone” would distinguish these cases from conventional skeletal myxoid chondrosarcoma.

ISSN:1072-4109    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:The condensed article reports the results of the histopathologic evaluation of the colorectal biopsy specimens from 14 patients who developed abdominal pain and bloody stools or diarrhea while receiving nonsteroidal anti-inflammatory drugs (NSAIDs). All patients had a mixed inflammatory infiltrate (predominantly neutrophilic in four patients and lymphocytic in two) and about one-half also had minimal crypt disarray. The intestinal symptoms resolved in all patients after NSAIDs were discontinued, but there was no histopathologic verification that the inflammatory changes had subsided.Nonspecific changes (“focal colitis”), similar to those described in this group, are present in most patients who undergo a colonoscopy for the investigation of diarrhea. This article calls attention on one of the possible and neglected causes for nonspecific colitis. However, larger controlled studies are needed to firmly establish a cause-and-effect relationship with NSAID intake.

ISSN:1072-4109    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:This commentary relates to ameliorative effects of myoepithelial cells in carcinomas of salivary glands and the breast as viewed not only by proliferative characteristics, but also by laboratory experiments and clinicopathologic evidence. The tumor suppressor action of myoepithelium is, in part, associated with its matrix-synthesizing and proteinase inhibitor properties. Loss of the myoepithelial phenotype yields a more aggressive carcinoma with enhanced invasive and metastatic capability.

ISSN:1072-4109    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:1999

数据来源: OVID