Epithelial markers

Demirkesen C, Hoede N, Moll R (1995) Epithelial markers and differentiation in adnexal neoplasms of the skin an immunohistochemical study including individual cytokeratins. JCutan Pathol 22(6) 518 535... 

Another way of increasing sensitivity and minimizing false negatives besides monoclonal antibody cocktails is to use antibody panels. Rather than test for just one epithelial marker such as cytokerafin to diagnose carcinoma, it... 

Some sarcomas besides epithelioid sarcoma or synovial sarcoma show coexpression of vimentin and keratin (18). Examining these tumors for the expression of other epithelial markers will help clarify their true nature. 

Although not specific for tissue lineage, these epithelial markers demonstrate characteristic immunostaining patterns for certain tissue types and therefore are useful in corroborating a diagnosis when used as part of a panel of antibodies. 

Best epithelial markers to distinguish adenocarcinomas from mesothelioma. 

Rosenberg AE, O Connell JX, Dickersin GR, Bhan AK. Expression of epithelial markers in malignant fibrous histiocytoma of the musculoskeletal system an immunohistochemical and electron microscopic study. Hum Pathol. 1993 24 284-293. 

Kwaspen EH, Smedts EM, Broos A, et al. Reproducible and highly sensitive detection of the broad spectrum epithelial marker keratin 19 in routine cancer diagnosis. Histopathology. 1997 31 503-516. 

Ben-Izhak O, Stark P, Levy R, et al. Epithelial markers in malignant melanoma. A study of primary lesions and their metasta-ses. Am J Dermatopathol. 1994 16 241-246. 

Multiple cytokeratin and epithelial markers may be necessary to show positive staining in the spindle cells, but... 

ITACs have features of a sinonasal-derived tumor but also share some immunohistochemical markers seen in the colorectal tumors that they resemble. For example, most ITACs will stain positive for CK7, which is the typical epithelial marker of the Schneiderian membrane. 456 They are also usually positive for CK20 and CDX2, which are typical of intestinal-derived malignancies.Villin and MUC2 have also been described in... 

Immunohistochemically, the fusiform and pleomorphic cells of STCs express vimentin. Labeling for keratin and EMA is also seen, but it may be quite focal (Fig. 11.34). This finding opens the door to the possibility that a small biopsy specimen could fail to demonstrate any epithelial markers because of sampling artifact. 

Marchevsky recently reviewed the application of immunohistochemistry to the diagnosis of malignant mesothelioma. Marchevsky stated that antibody panels that had been proposed for the distinction between malignant mesothelioma and other neoplasms included two or more epithelial markers used to exclude the diagnosis of carcinoma (e.g., monoclonal and polyclonal CEA, BerEP4, B72.3, CD 15, MOC-31,... 

Another contentious issue concerns the aberrant expression of keratin and EMA in smooth muscle tumors. Although some authors have reported a high incidence of that phenomenon in general, with no particular reference to specific soft tissue sites,the authors experience indicates that cutaneous leiomyomas and leiomyosarcomas only rarely show the presence of epithelial markers. 

Heyderman E, Graham RM, Ghapman DV, et al. Epithelial markers in primary skin cancer an immunoperoxidase study of the distribution of epithelial membrane antigen (EMA) and carcinoembryonic antigen (GEA) in 65 primary skin carcinomas. Histopathology. 1984 8 423-434. 

SPN typically expresses a nonspecific acinar marker, ai-antityripsin, similar to ACC however, it also consistently expresses vimentin, CD56, 3-catenin, CD10, and progesterone receptors. Furthermore, in SPN, in contrast with ACC, more specific acinar markers (trypsin, chymotrypsin, and lipases) are not expressed and epithelial markers are usually either focal or weak. 

Heyderman E, Brown BM, Richardson TC. Epithelial markers in prostatic, bladder, and colorectal cancer an immunoper-oxidase study of epithelial membrane antigen, carcinoembry-onic antigen, and prostatic acid phosphatase. J Clin Pathol. 1984 37 1363. 

Immunohistochemistry is an invaluable adjunct technique because of the potential for many different neoplasms to display a rhabdoid appearance. Figure 17.27 shows an immunohistogram of the most frequently found markers in MRT, compiled from four series. 793,i97,200 MRT is typically a polyphenotypic neoplasm with coexpression of vimentin (Fig. 17.28) at least one epithelial marker such as cytokeratin (Fig. 17.29) or epithelial membrane antigen (Fig. 17.30) neuroectodermal markers such as neuron-specific enolase, synaptophysin... 

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