Stains & molecular markers
Epithelial membrane antigen (EMA)
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Epithelial membrane antigen [title]
Epithelial membrane antigen (EMA)
Author: Nat Pernick, M.D.
Topic Completed: 1 May 2012
Minor changes: 8 October 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Epithelial membrane antigen [title]
Table of Contents
Definition / general | Pathophysiology | Clinical features | Uses by pathologists | Microscopic (histologic) images | Positive staining - normal | Positive staining - disease | Negative staining | Additional referencesCite this page: Pernick N. Epithelial membrane antigen (EMA). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stainsema.html. Accessed January 22nd, 2021.
Definition / general
- Also called CD227, MUC1 and episialin
- Large cell surface mucin glycoprotein expressed by most glandular and ductal epithelial cells and some hematopoietic cells
Pathophysiology
- Normally acts as barrier to apical surface of epithelial cells, playing a protective and regulatory role
- Inhibits formation of E-cadherin / beta catenin complex
- Micropapillary carcinoma may be due to reversal in cell polarity of MUC1, changing from apical surface (normal) to stroma-facing surface (micropapillary carcinoma, Mod Pathol 2004;17:1045)
- Partial reverse cell polarity may identify breast carcinomas that represent part of spectrum of invasive micropapillary carcinoma but lack its morphology (Am J Surg Pathol 2010;34:1637)
- Reactive gastropathy associated with loss of MUC1 expression in 67% of cases, may play a role in development of its serrated profile (Arch Pathol Lab Med 2007;131:86)
Clinical features
- Highly expressed by most adenocarcinomas, associated with poor prognosis (Hum Pathol 1995;26:432)
- In breast cancer, aberrant cytoplasmic and membranous localization (associated with micropapillary subtype) is associated with poor outcome (Mod Pathol 2005;18:1295)
- Shed into the bloodstream of adenocarcinoma patients, used in commercial serum tumor marker assays (CA15-3)
Uses by pathologists
- Common epithelial marker
- Marker of meningioma
- Marker of Paget disease (Am J Surg Pathol 2001;25:1469)
- In breast and bladder micropapillary carcinoma, MUC1 stains stroma-facing surface of cell clusters (basal), which accentuates outlines of micropapillary units to form a distinct band on this surface
- Distinguish systemic anaplastic large cell lymphoma (MUC1+) from cutaneous anaplastic large cell lymphoma (usually MUC1-, Am J Surg Pathol 2008;32:1421)
Microscopic (histologic) images
Contributed by Jijgee Munkhdelger, M.D., Ph.D. and Andrey Bychkov, M.D., Ph.D.
Epithelioid mesothelioma immunoprofile
Epithelioid mesothelioma EMA
Contributed by Ihab Hosny, M.D.
Cervix, Adenoid cystic carcinoma
Cases #219, 150, 48, 154, 69 and 149
Bladder, high grade urothelial carc
Heart, synovial sarcoma
Kidney, papillary carcinoma, solid
Pancreas, IPMN, intestinal, MUC1-
Scrotum, epithelioid sarcoma
Soft tissue, parachordoma
Images hosted on other servers:
CNS, meningioma, EMA+, F4
Pancreas, micropapillary carcinoma
Pancreas, MUC1 staining
Positive staining - normal
- Apical surface of almost all glandular and ductal epithelial cells including breast (and Toker cells), kidney distal tubules, lung (type II pneumocytes), pancreas, salivary glands, skin (eccrine and apocrine glands)
- Activated T cells, some B cells, monocytes, follicular dendritic cells and perineurial cells
Positive staining - disease
- Adenocarcinomas (breast, colorectal, pancreatic, other)
- Carcinoid tumor, chordoma
- Choriocarcinoma
- Desmoplastic small round cell tumor
- Epithelioid sarcoma
- Follicular dendritic cell sarcoma, interdigitating dendritic cell / reticulum cell sarcoma
- Lung: type II pneumocyte lesions (type II cell hyperplasia, dysplastic type II cells, apical alveolar hyperplasia)
- Lymphoma: anaplastic large cell, diffuse large B cell (variable), plasmablastic, primary effusion
- Meningioma
- Mesotheliomas (epithelioid)
- Myeloma
- Paget’s disease
- Perineurioma
- Plasmacytomas
- Renal cell carcinoma
- Synovial sarcoma (epithelial areas)
- Thymic carcinoma (often)
Negative staining
- Myoepithelial cells
- Adrenal and hepatocellular carcinoma, germ cell tumors (except choriocarcinoma)
- Acquired cystic disease associated renal cell carcinoma
- Leiomyosarcoma (usually), liposarcoma
- Melanoma
- Neuroblastoma
- Paraganglioma
- Solitary fibrous tumor
Additional references
