Epithelial Membrane Antigen (EMA)
Masahiko Mori in Histochemistry of the Salivary Glands, 2019
Epithelial membrane antigen (EMA) is a high molecular weight glycoprotein, low in protein and high in carbohydrate, with galactose and N-acetylgalactosamine residues as major sugars. It is isolated from human milk fat globule membrane.1 Polyclonal and monoclonal antibodies to EMA have been used in pathologic studies.2–8 Immunohistochemical deposition of EMA has been found at luminal surfaces of glandular structures, lateral borders of acinar cells, and in cytoplasms of squamous-cells of tumors. Reactivity of EMA is limited to human tissues. EMA does not cross-react to the other species. Immunohistochemical methods have detected EMA in normal human salivary glands, obstructive lesions, and many types of tumors.9,10 Two patterns appear in salivary gland lesions: surface-positive and whole cell-positive types.9 The former distribution is similar to carcinoembryonic antigen (CEA) when polyclonal CEA antibody is used, but is different when monoclonal CEA antibody is used. EMA immunohistochemistry may be used in diagnostic surgical pathology for epithelial, mesenchymal, and hematopoietic tumors in paraffin sections.11–14
The Non-Hodgkin’s Lymphomas and Plasma Cell Dyscrasias
Harold R. Schumacher, William A. Rock, Sanford A. Stass in Handbook of Hematologic Pathology, 2019
The immunophenotype of plasma cell myeloma and plasmacytoma is similar to benign plasma cells. Like benign plasma cells, the neoplastic cells express cytoplasmic, but not surface, immunoglobulin. However, unlike reactive process, which contains a mixture of kappa-and lambda-positive plasma cells, neoplastic plasma cells express monoclonal immunoglobulin and show a light chain restriction. A population is said to demonstrate a light chain restriction when the ratio of one light chain type to the other exceeds 16:1. Both benign and malignant plasma cells fail to express most B-cell-associated antigens, such as CD19, CD20, and CD22. However, they express the B-cell-associated antigen CD79a, which is also expressed on plasma cells. Like benign plasma cells, the neoplastic cells are usually negative for CD45 (leukocyte common antigen), positive for CD38 and the mature plasma cell antigens, PC-1, and PCA-1. They also may express epithelial membrane antigen (EMA). Neoplastic plasma cells, but not benign plasma cells, stain with the antibody MB2, and also often epxress CD56, an adhesion molecule that is associated with natural killer cell differentiation. A minority of cases express CD10 (CALLA), and markers of myelomonocytic differentiation, such as CD11b, CD11c, CD13, CD15, and CD33.
Pathology and Epidemiology
John T. Kemshead in Pediatric Tumors: Immunological and Molecular Markers, 2020
Neuron-specific enolase can also be identified immunohistologically in the cytoplasm of cells of the neuroblastoma lineage. Many investigators find that this antigen is expressed poorly, if at all, in those morphologically undifferentiated tumors where diagnostic assistance is most needed. Tsokos et al.,33 found that this cytoplasmic component was demonstrable in every one of a group of neuroblastomas which they investigated, while it was found in one rhabdomyosarcoma among a large, heterogeneous group of other tumors. A similar criticism can be leveled at S-100 protein in neuroblastoma, in that it is only expressed in the better differentiated tumors, but in this latter group it has proved to be of some diagnostic value. Epithelial-membrane antigen is another marker of considerable value demonstrable immunohistologically on the surface of epithelial-derived tumors such as primary or secondary carcinomas.
Cranio-spinal Rosai Dorfman disease: case series and literature review
Published in British Journal of Neurosurgery, 2019
Shashank S. Joshi, Shilpa Joshi, Girish Muzumdar, Keki E. Turel, Rajan M. Shah, Indoo Ammbulkar, Muhammad Masood Hussain, Kishor A. Choudhari
Immunohistochemistry-The characteristic RDD histiocytes are strongly positive for S-100 protein (Figure 4(B)) and CD 68 and negative for CD 1a.45,46 Staining for CD 20 and CD 3 show mixed populations of B and T lymphocytes in the background. Kappa and lambda light chain immunohistochemistry show polytypic staining in the plasma cell infiltrates. The stain for epithelial membrane antigen (EMA) decorates plasma cells and meningeal cells. Immunohistochemistry finding in various conditions which can mimic cranial RDD are summarised in Table 3.47 Intracranial Hodgkin’s disease is rare and is typically associated with relapse.48 Classic Reed Sternberg cells can readily distinguish them from RDD histiocytes. Classic Reed Sternberg cells and variants, lack emperipolesis and S-100 immunoreactivity and are typically positive for CD 15 and CD 30.49 Intracranial affection by plasmacytoma is relatively rare but similar to the case of intracranial RDD, these lesions are dural-based. This diagnosis is easily excluded by demonstrating plasma cell infiltrates of plasmacytoma are monoclonal whilst RDD are polyclonal.50,51 Plasma cell granuloma is a discrete, inflammatory mass lesion attached to dura and associated with fibrosis.52–55 Many lesions previously reported as intracranial plasma cell granulomas or inflammatory pseudotumours are in fact RDD.56–58 The various differential diagnoses for craniospinal RDD are summarised in Table 3 and include meningioma, lymphoma, plasmacytoma and chordoma.
Sinonasal undifferentiated carcinoma with metastasis to the extradural spine
Published in British Journal of Neurosurgery, 2023
Samuel Jones, Heather O’Connor, Fraser Henderson, Adriana Olar, Sunil Patel
SNUC is diagnosed by histopathological examination. Grossly, these tumors are usually larger than four centimeters with fungating, ill-defined margins. Invasion into adjacent structures and anatomic compartments with bone destruction is common. Histologically, the tumor is characterized by a submucosal cellular proliferation with lobular and trabecular growth patterns predominating. The cellular infiltrate consists of polygonal medium- to large-sized cells with a high nuclear-to-cytoplasmic ratio, eosinophilic cytoplasm, and well-defined borders. The nuclei can be hyperchromatic or vesicular with variably prominent nucleoli. SNUCs have a high mitotic rate with prominent confluent tumor necrosis and individual cell apoptosis. As seen in our case, lymph-vascular and perineural invasion are common.7 These tumors are consistently positive for neuron specific enolase.8 About 50% of cases will also express epithelial membrane antigen.7 We present here the histopathological features of this SNUC tumor (Figure 2) from the original resection specimen (day +8) and the cervical spine metastasis (day +302).
Clinical value of a diagnostic score for colon cancer based on serum CEA, CA19-9, cytokeratin-1 and mucin-1
Published in British Journal of Biomedical Science, 2018
AM Attallah, M El-Far, AR Ibrahim, MA El-desouky, MM Omran, MS Elbendary, KA Attallah, ER Qura, SO Abdallah
Biomarkers can be used for detecting early stage of colon cancer [15]. Higher levels of mucins and cytokeratins have been found in hepatocellular carcinoma, breast and colon cancers, and play important roles in diagnosis and prognosis of colon cancer [16,17]. In the present study, using western blot analysis CK1 was identified at 67 kDa and MUC1 was identified at 130 kDa in sera of patients with colon cancer and patients with a benign condition. Several authors reported that CK1 have high molecular weight range (40–68 kDa) [17–20]. MUC epithelial membrane antigen molecular weight ranging from 35 to 1500 kDa have been reported [13,21,22]. We report a significant increase in serum CK1 and MUC1 levels in patients with colon cancer compared with healthy controls and those with a benign growth. In the cancer patients, CK1 and MUC1 levels increased with late stage, positive lymph node invasion, and with distant organ metastasis. The high level of MUC1 may be explained in terms of inflammation and immunity, and have been previously reported in a small study [23].
Related Knowledge Centers
- Epithelium
- Glycosylation
- Mucin
- Oligosaccharide
- Variable Number Tandem Repeat
- Glycoprotein
- Pathogen
- Gene
- O-Linked Glycosylation
- Sheddase