Epithelial membrane antigen (EMA)

Stains
Epithelial membrane antigen (EMA)

Author: Nat Pernick, M.D.

Topic Completed: 1 May 2012

Revised: 5 April 2019

Copyright: 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: Epithelial membrane antigen [title]

Page views in 2018: 22,531

Page views in 2019 to date: 14,108

Table of Contents

Cite this page: Pernick N. Epithelial membrane antigen (EMA). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stainsema.html. Accessed July 21st, 2019.

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

Images hosted on PathOut server:

Bladder, high grade urothelial carc

Cervix, adenoid cystic carcinoma

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

Colon, perineurioma of perineum, 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

J Leukoc Biol 2002;72:692