Pathology Outlines

Stains
ERG

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

Revised: 1 August 2018, last major update November 2012

Copyright: (c) 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: ERG [title]

Table of Contents

Cite this page: Pernick, N. ERG. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/stainserg.html. Accessed August 20th, 2018.

Definition / general

Transcription factor highly specific and 50% sensitive for prostatic adenocarcinoma
Detect via FISH or immunohistochemistry

Terminology

V-ets erythroblastosis virus E26 oncogen homologue
ETS family transcription factor present at 22q12

Uses by pathologists

TMPRSS2-ERG fusion is one of most common translocations for any malignancy
- 50% sensitive and highly specific for prostate adenocarcinoma, usually by FISH (Am J Surg Pathol 2007;31:882)
- Lower frequency (28%) in patients from Japan (Mod Pathol 2010;23:1492) and Korea (Korean J Pathol 2012;46:423)
ERG immunohistochemistry (nuclear stain) accurately assesses presence of TMPRSS2-ERG fusion protein
- Simpler and less costly than FISH (Am J Surg Pathol 2011;35:1014)
IHC is more specific for prostatic adenocarcinoma than AMACR
- Staining of atypical focus is specific for carcinoma if high-grade PIN can be excluded (Arch Pathol Lab Med 2012;136:935, Hum Pathol 2013;44:786)
Differentiate small cell carcinoma of prostate (positive) from bladder (negative, Mod Pathol 2011;24:1120)
Strong nuclear ERG immunoreactivity is specific for Ewing sarcoma / PNET with EWSR1-ERG rearrangement / t(21;22)(q22;q12) (Mod Pathol 2012;25:1378)
Component of fusion protein in acute myeloid leukemia (J Clin Oncol 2009;27:5031)

Diagrams / tables

Images hosted on other servers:

TMPRSS2:ERG gene rearrangements

ERG rearrangement

Clinical features

TMPRSS2-ERG fusion may be an early event in prostate cancer (Arch Pathol Lab Med 2009;133:1033), although marked intrafocal heterogeneity exists (Mod Pathol 2013;26:106)
ERG does not appear to have prognostic value in prostate adenocarcinoma after radical prostatectomy (Mod Pathol 2012;25:471) or in high grade PIN (BJU Int 2012;110:E751)
ERG rearrangement is more common in peripheral zone prostatic adenocarcinomas, but also present in 12% of transition zone cancers (Mod Pathol 2010;23:1499)
Similar TMPRSS2-ERG gene fusion status between primary and metastatic prostate cancers (Hum Pathol 2012;43:644)
Quantification of T2:ERG in postdigital rectal examination urine is specific for prostate cancer (Am J Clin Pathol 2012;138:685)

Microscopic (histologic) images

Images hosted on other servers:

Prostate, adenocarcinoma

Prostate, small cell carcinoma

Prostate needle biopsies

Prostatectomy specimens

HGPIN

Positive staining - normal

Endothelial cells, some bone marrow precursors
Also early fetal mesenchyme and subpopulations of fetal cartilage (Am J Surg Pathol 2011;35:432)

Positive staining - disease

Prostatic adenocarcinoma (40 - 60%), 20 - 30% of HGPIN or benign glands adjacent to prostatic adenocarcinoma (Am J Surg Pathol 2011;35:1062) and other HGPIN or benign glands (Am J Surg Pathol 2011;35:608, Mod Pathol 2011;24:1128)
Prostatic small cell carcinoma, but not small cell carcinoma from lung or bladder (Hum Pathol 2011;42:11, Mod Pathol 2011;24:820)
Vascular tumors (> 90%): angiosarcoma, epithelioid hemangioendothelioma, hemangioma, Kaposi sarcoma and lymphangioma (Am J Surg Pathol 2011;35:432)
Ewing sarcoma associated with EWSR1-ERG rearrangement (strong nuclear staining)

Negative staining

Benign prostatic glands distant from adenocarcinoma
Most other carcinomas and epitheliod tumors (Mod Pathol 2010;23:1061)

Molecular / cytogenetics images

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Prostatic adenocarcinoma (FISH)

Prostatic small cell carcinoma, FISH for ERG