Glutamine synthetase by IHC

Alphabetical Test listing

Glutamine synthetase by IHC-12376 - Technical only, 12379 - Technical & interpretation

Test name:

Test number:

12376 - Technical only, 12379 - Technical & interpretation

Excellian order number:

LAB12376
LAB12379

Alternate names:

Tests included:

All IHC stains will include a positive control tissue

Useful for:

In normal liver, GS is present in the centrilobular regions of the liver, usually around the central veins
In FNH of the liver, GS is present in large groups of hepatocytes, in an anastomosing pattern, typically around hepatic veins (referred to as a geographic or "map-like" pattern)
HA show no staining, focal staining of hepatocytes around central veins, or patchy staining at the periphery (non-uniform and non-intense)
Diffuse GS staining is seen in 13-70% of early hepatocellular carcinomas (HCC)
High-grade dysplastic nodules (HGDN) are either GS negative, or show patchy positive staining for GS

Specimen type:

Tissue

Processing instructions:

Submit a formalin-fixed, paraffin-embedded tissue

Transport container:

Formalin-fixed, paraffin-embedded (FFPE) tissue block

Alternate transport container:

FFPE tissue section mounted on a charged, unstained slide

Transport and stability:

Ambient (preferred)

Reason for rejection:

Unlabeled/mislabeled block
Insufficient tissue
Slides broken beyond repair

Performing lab:

AHL - Immunohistochemistry

Days set up:

Mo - Fr

TAT:

1 - 2 days

Method:

Immunohistochemical staining and microscopic examination

Reference ranges:

If requested, an interpretive report will be provided

Clinical information:

Specifications

Glutamine synthetase (GS) is an enzyme that converts glutamate and ammonia to glutamine
GS can be used in a panel with serum amyloid A and beta catenin to help differentiate between hepatic adenomas (HA) and focal nodular hyperplasia (FNH)

Staining pattern

Strong cytoplasmic staining

References

Shafizadeh N et al: Diagnosis of well-differentiated hepatocellular lesions: role of immunohistochemistry and other ancillary techniques. Adv Anat Pathol 2011;18:438-445).
Joseph NM et al: Diagnostic utility and limitations of glutamine synthetase and serum amyloid-associated protein immunohistochemistry in the distinction of focal nodular hyperplasia and inflammatory hepatocellular adenoma. Modern Pathology (2014) 27, 62-72; doi:10.1038/modpathol.2013.114.

CPT codes:

88342 - 1st stain
88341 - each additional stain

Date created:

07/03/2017

Revised date:

10/18/2018

Review date:

01/12/2024