Search results for "keratin"
showing 10 items of 303 documents
Increased numbers of cytokeratin-positive interstitial reticulum cells (CIRC) in reactive, inflammatory and neoplastic lymphadenopathies: hyperplasia…
1995
A total of 291 enlarged lymph nodes showing a range of reactive-inflammatory processes, primary and metastatic neoplasms were studied to determine the distribution and immunoprofile of their cytokeratin-positive interstitial reticulum cells (CIRC) in comparison with normal nodes. In 258/291 nodes (89%), CIRC numbers were distinctly increased in the subcapsular, paracortical and, occasionally, in the medullary zones; often, these increased CIRC formed networks around follicles, sinuses and vessels. CIRC had comparatively small, irregularly shaped bodies and dendritic processes; occasionally, giant forms were noted. CIRC contained cytokeratins (CK) 8 and 18 but not 19, as shown by immunohisto…
Biological and prognostic significance of stratified epithelial cytokeratins in infiltrating ductal breast carcinomas
1998
The biological significance of the differential expression of cytokeratin (CK) polypeptides in breast carcinomas is unclear. We examined the CK profiles of 101 primary infiltrating ductal breast carcinomas using monoclonal antibodies directed against 11 different CKs and against vimentin. Two major CK phenotypes were distinguished: first, a phenotype expressing only the simple-epithelial CKs 7 (variably), 8, 18 and 19, and secondly, a bimodal phenotype co-expressing significant amounts of one or more of the stratified-epithelial CKs 4, 14 and 17. The vast majority of G1 and G2 carcinomas had the simple-epithelium phenotype, as did a subgroup of G3 carcinomas. Interestingly, the majority (62…
Complex and Differential Cytokeratin Profiles in Thymomas and Correlation with Normal Thymus
1997
Cytokeratins (CKs) are characterized by highly diverse expression patterns and thus serve as potent epithelial differentiation markers. We have studied 31 cases of thymomas (12 cortical, 2 predominantly cortical, 5 mixed, and 9 medullary type thymomas as well as 3 well-differentiated thymic carcinomas) and, for comparison, 15 normal thymi, for the presence of different CK polypeptides. Immunohistochemistry was performed on cryostat sections using the indirect immunoperoxidase method.
Clear Cell Syringoid Carcinoma
2000
Syringoid carcinoma (syringoid "eccrine" carcinoma or eccrine epithelioma) is a rare cutaneous tumor with some controversy regarding its correct definition. It may also be difficult to differentiate from its benign counterpart (syringoma), other adnexal carcinomas, and cutaneous metastasis from adenocarcinomas. We present a case of a syringoid carcinoma of the clear cell variant complemented with an immunohistochemical and ultrastructural study, the latter revealing cytoplasmic accumulation of glycogen and presence of intercellular and intracellular lumina in clear tumor cells, as well as diverse hallmarks of malignancy (i.e., perineural invasion, tumor necrosis, and deep invasion). Clear t…
Characterization of a Human Carcinosarcoma Cell Line of the Ovary Established after in Vivo Change of Histologic Differentiation
2001
Abstract Objectives. Cell lines are valuable in vitro models for clinical and basic research. Most ovarian cancer cell lines described are serous cystadenocarcinomas or poorly differentiated adenocarcinomas. The establishment of ovarian cancer cell lines with rare histologic differentiation is especially of interest. We describe the establishment of a carcinosarcoma cell line of the ovary after in vivo selection. Methods. The cell line OV-MZ-22 was established from a solid tumor mass in the upper abdomen. At the time of establishment, the patient underwent secondary debulking and was pretreated with six cycles of cis -platinum/epirubicin/cyclophosphamide. Features of the cell line studied i…
Sarcomatoid carcinoma of urinary bladder: Immunohistochemical study of an uncommon case
2002
A case of sarcomatoid carcinoma of the bladder is reported herein. Immunohistochemical staining with human pancytokeratin antibody was negative, while vimentin staining was strongly positive, suggesting a diagnosis of sarcoma of the bladder. Further immunohistochemical analysis revealed positivity for AE1/AE3 cytokeratins, permitting a correct diagnosis of sarcomatoid carcinoma of the bladder. It can be difficult to distinguish between sarcomatoid carcinoma, undifferentiated carcinoma and sarcoma, particularly if the biopsy specimens are of small size. In rare cases, sarcomatoid tumors may express epithelial markers different from those revealed by human pancytokeratin staining. Copyright ©…
Cytokeratin and Vimentin Expression in Primary and Recurrent Carcinoma of the Vulva
1996
Radical vulvectomy for the treatment of a vulvar carcinoma inevitably entails severe psychosexual consequences for the patients. Thus, for such tumors, reliable histological prognostic parameters are needed to allow; when appropriate, the use of less radical operative measures. One possible approach to this problem might be to examine tumors immunohistochemically for the presence of cytoskeletal components. To assess the utility of this method, we applied a panel of antibodies directed against cytokeratins (CKs) and vimentin to a groups of vulvar carcinomas (62 primary and 35 recurrent tumors) and examined the results for possible correlations with the course of disease and various clinical…
Merkel cells in ontogenesis of human nails
1993
Digital skin of human fetuses is known to contain a particularly high concentration of Merkel cells. Using antibodies against the simple epithelial cytokeratins (CK) 18 and 20, which are sensitive and specific Merkel cell markers, we studied immunohistochemically the main adnexal structure of digital skin, the nail anlage, in human fetuses (9-22 weeks of gestation) for the presence of Merkel cells. As early as week 9 some clustered Merkel cells were detected in the early matrix primordium. In specimens of week 12-15, abundant Merkel cells were found in the nail anlagen, particularly in the epithelium of the proximal nail-fold and the dorsal and ventral side of the apex region. In contrast, …
Formation of Epidermal and Dermal Merkel Cells During Human Fetal Skin Development
1986
The origin of Merkel cells is still a matter of debate, specifically the question of whether they are derived from epithelial cells of the epidermis or from immigrated neural crest cells. As an argument for the latter hypothesis the occurrence of dermal, nerve-associated Merkel cells in human fetal skin has often been mentioned. Therefore, we analyzed the distribution of Merkel cells in epidermis and dermis of plantar skin of human embryos and fetuses, ranging in gestational age between 7 and 17 weeks. Merkel cells were identified by immunocytochemistry on frozen sections using antibodies against simple epithelium-type cytokeratins and by electron microscopy. In the 17-week-old fetus, 17% o…
An immunohistochemical and biochemical study of cytokeratin polypeptides in a non-Paget type adenocarcinoma of the vulva
1988
SummaryThe intermediate filament composition was studied in a malignant neoplasm of the vulva in a 42 year old patient. The absence of vimentin excluded the diagnosis of malignant melanoma. Anaplastic squamous cell carcinoma could be excluded by the presence of glandular type cytokeratins numbers 7, 8, 18, 19 in the neoplastic cells. Intermediate filament typing did not support a diagnosis of epithelioid sarcoma. Since the typical epidermal involvement by tumour cells was lacking, Paget's disease was excluded. Metastatic adenocarcinoma was excluded by the lack of relevant clinical findings. It was concluded that the lesion represented an adenocarcinoma of the vulva of the non-Paget type mos…