Stains
Epithelial Membrane Antigen (EMA)

Author: Nat Pernick, M.D. (see Authors page)

Revised: 11 November 2015, last major update May 2012

Copyright: (c) 2002-2015, PathologyOutlines.com, Inc.

PubMed Search: Epithelial Membrane Antigen [title]

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)
Micro Images

Images hosted on PathOut server:

Missing Image

Bladder, high grade urothelial carc

Missing Image

Cervix, adenoid cystic carcinoma

Missing Image

Heart, synovial sarcoma

Missing Image

Kidney, papillary carcinoma, solid

Missing Image

Pancreas, IPMN, intestinal, MUC1-

Missing Image

Scrotum, epithelioid sarcoma

Missing Image

Soft tissue, parachordoma



Images hosted on Other servers:

Missing Image

Bladder, high grade urothelial carc

Missing Image

CNS, meningioma, EMA+, F4

Missing Image

CNS, meningioma, chordoid (L), clear cell (R)

Missing Image

CNS, papillary ependymoma

Missing Image

Colon, perineurioma of perineum, F4

Missing Image

Pancreas, micropapillary carcinoma

Missing Image Missing Image

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