Basal phenotype of ductal carcinoma in situ: recognition and immunohistologic profile.
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The basal phenotype of breast carcinoma was demonstrated from a study of gene expression profiles, which demonstrated five carcinoma phenotypes with differing immunohistologic profiles and outcomes. The basal phenotype, so-named because of an immunohistologic profile that is similar to myoepithelial cells of the breast, has poor outcomes. While the invasive basal phenotype has been described, there is a paucity of literature regarding the existence or recognition of a precursor lesion. We searched our CoPath database for breast carcinomas in the age group of 37 years or less, and this yielded 98 cases from the years 2001 to April 2006. Pathology reports were screened for those cases that were negative for estrogen and progesterone receptors and HER-2/neu (triple negative). A total of 16 cases (16/98, 16%) fulfilled these criteria. Histology was reviewed and immunostains were performed for Cytokeratins 14, 17, and 5/6, vimentin, EGFR, c-kit, smooth muscle actin and p63. All 16 cases had a high-grade invasive ductal carcinoma, Nottingham score 9/9, with geographic necrosis, good circumscription and lymphoid infiltrates. Of the 16 cases, 13 exhibited at least one area of ductal carcinoma in situ (DCIS). The DCIS types were solid, flat or micropapillary, high nuclear grade, with comedonecrosis and invariably associated with intense lymphoid inflammatory cell infiltration. Of 16 invasive cases, 14 (88%) were positive for CK14, CK17, CK5/6 and EGFR; 94% were vimentin positive, while half or less of cases were positive for smooth muscle actin, c-kit or p63. All of the DCIS components demonstrated the same immunohistologic profile as the invasive component. A DCIS component of solid, flat or micropapillary type exists in the basal phenotype of breast carcinoma, and it demonstrates the same immunophenotype as the invasive carcinoma, typically positive for CK5/6, CK14, CK17, vimentin and EGFR, but negative for ER/PR and HER-2/neu. (+info)
CK17 and p16 expression patterns distinguish (atypical) immature squamous metaplasia from high-grade cervical intraepithelial neoplasia (CIN III).
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AIMS: Atypical immature metaplasia (AIM) refers to a full-thickness intraepithelial basaloid lesion in the uterine cervix that features both metaplasia and atypia and is therefore difficult to distinguish from high-grade cervical intraepithelial neoplasia (CIN III). p16 is a marker for human papillomavirus (HPV)-induced dysplasia. Cytokeratin (CK) 17 is a marker for cervical reserve (stem) cells, which give rise to metaplasia. The aim was to determine whether AIM can be reclassified into metaplasia and CIN III based on p16 and CK17 immunohistochemistry. MATERIAL AND RESULTS: Seventy-five cervical biopsy specimens, curettings and cone excisions containing varying proportions of dysplasia and metaplasia and 20 cases regarded as AIM were analysed immunohistochemically with antibodies to CK17, p16 and p63. In immature metaplasia all proliferating cells were immunoreactive with antibodies to CK17 and p63, while p16 was negative. All dysplastic cells of CIN III demonstrated uniform immunoreactivity for p16 and p63, but were CK17-. Based on the reciprocal immunoreactivity of p16 and CK17, 17/20 cases of AIM were reclassified as metaplasia (n = 10) and CIN III (n = 7). Three cases of AIM stained for both CK17 and p16 and were classified as CIN III. CONCLUSION: 'AIM' is a helpful histological descriptor but it should not be used as a final diagnosis. Immunohistochemistry for p16 and CK17 allows distinction between metaplasia and high-grade CIN. (+info)
Pachyonychia congenita associated with median rhomboid glossitis.
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A 3-year-old girl presented with subungual hyperkeratosis and nail plates with increased transverse curvature, distal elevation, yellow-brown discoloration, and mild thickening. The changes, which affected all 20 nails, had developed during the first year of life. Mucocutaneous examination showed the presence of median rhomboid glossitis. The patient's mother had similar nail changes, which had been present since infancy as well as a focal plantar keratoderma and hyperhidrosis. The patient's clinical presentation and history were compatible with a diagnosis of pachyonychia congenita, a rare heritable disease that affects the nails, skin, oral and laryngeal mucosae, teeth, and hair. Dominant-negative mutations in four keratin genes (K6a, K6b, K16, and K17) lead to keratinocyte fragility and the resultant pachyonychia congenita phenotype. Successful targeted therapies are currently lacking for this oftentimes disabling disorder. Although oral manifestations are a common feature of PC, to our knowledge, this represents the first report of median rhomboid glossitis in association with PC. (+info)
Differentiation between pancreaticobiliary and upper gastrointestinal adenocarcinomas: is analysis of cytokeratin 17 expression helpful?
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Metastatic adenocarcinoma of unknown primary site, eg, to lymph nodes, liver, or lung, may originate from many organs. Microscopic differentiation of adenocarcinomas from the pancreaticobiliary and upper gastrointestinal tracts may be difficult because of shared histologic and immunohistologic features. A high prevalence of cytokeratin (CK)17 expression in pancreaticobiliary adenocarcinoma was reported, and preliminary data indicate infrequent or missing expression in gastric adenocarcinoma. The prevalence of CK17 expression in gastric cardiac and esophageal adenocarcinomas has not been studied. We studied CK17 expression in tissue microarrays of 67 distal gastric, 71 gastric cardiac, and 46 esophageal adenocarcinomas and compared it with expression in 55 pancreatic, 23 extrahepatic bile duct, and 49 colorectal adenocarcinomas. CK17 expression was as follows: pancreatic, 88%; bile duct, 59%; esophageal, 30%; distal gastric, 28%; gastric cardiac, 27%; and colorectal adenocarcinoma, 6%. These differences were statistically significant for all tumor types except in comparisons of esophageal, cardiac, and distal gastric adenocarcinoma. The prevalence of CK17 expression in pancreatic and extrahepatic bile duct adenocarcinomas is substantially higher than in upper gastrointestinal tract and colorectal adenocarcinomas. However, in individual cases of adenocarcinoma of unknown primary site, CK17 results alone are insufficient to differentiate the analyzed tumor entities. (+info)
Abortive placode formation in the feather tract of the scaleless chicken embryo.
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The featherless phenotype of the scaleless mutant provides a model for delineating the process of feather follicle formation. Initial studies established that the mutation affects the epidermis and suggested that epidermis is unable to respond to signals from underlying dermis, or propagate a reciprocal signal. The work presented here demonstrates that scaleless epidermis does indeed respond to the initial inductive signals from dermis, as indicated by the localization of nuclear beta-catenin and transient focal expression of genes expressed in the placode of wild-type feather rudiments. In the sporadic "escaper" feathers that form in scaleless, expression of many genes associated with the progression of feather development is comparable to that in wild-type embryos. An exception is the ectodysplasin receptor gene Edar, which is expressed at lower levels in mutant feather buds. These observations suggest that the scaleless mutation impairs the locally augmented expression of Edar required to stabilize the placodal fate and sustain feather development. (+info)
Role of the Notch ligand Delta1 in embryonic and adult mouse epidermis.
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The Notch ligand Delta1 (Dll1) is expressed in human interfollicular epidermis (IFE) and regulates differentiation and adhesion of cultured human keratinocytes. However, the consequences of deleting Dll1 in mouse epidermis have not been examined. Here, we report that in embryonic mouse skin Dll1 is expressed by patches of keratinocytes in the basal layer of the IFE and in the dermal papilla and hair bulb. In a Dll1 hypomorph mutant that survives until birth, hair follicles formed normally but proliferation and thickness of the IFE were increased. Deletion of Dll1 using Cre recombinase expressed under the control of the keratin-5 (K5) promoter resulted in a delay in the first postnatal anagen, but subsequent hair cycles were normal. As in the hypomorph, IFE proliferation was stimulated and expression of K10 and K17 was disturbed. Older mice developed tumors with elements of IFE differentiation. Keratinocytes cultured from K5Cre x Dll1(flox/flox) epidermis showed a transient increase in proliferation, with a subsequent decrease in integrin expression and increased terminal differentiation. These results demonstrate that Dll1 contributes to the control of proliferation and differentiation in IFE, whereas Jagged1 regulates hair follicle differentiation. (+info)
Basal cytokeratins in breast tumours among BRCA1, BRCA2 and mutation-negative breast cancer families.
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