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Test Code GCET Germinal Center B-cell Expressed Transcript 1 (GCET1) Immunostain, Technical Component Only

Advisory Information

This test includes only technical performance of the stain (no pathologist interpretation is performed). If diagnostic consultation by a pathologist is required order PATHC / Pathology Consultation.

Shipping Instructions

Attach the green pathology address label and the pink Immunostain Technical Only label included in the kit to the outside of the transport container.

Specimen Required

Supplies: Immunostain Technical Only Envelope (T693)

Specimen Type: Tissue

Container/Tube: Immunostain Technical Only Envelope (T693)

Preferred: 2 Unstained positively charged glass slide (25- x 75- x 1-mm) per test ordered; sections 4-microns thick

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

Secondary ID


Useful For

Classification of lymphomas

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
IHTOI IHC Initial, Tech Only No No
IHTOA IHC Additional, Tech Only No No

Method Name


Reporting Name

GCET1 IHC, Tech Only

Specimen Type


Specimen Stability Information

Specimen Type Temperature Time
TECHONLY Ambient (preferred)

Reject Due To








Wet/frozen tissue, Cytology smears, Nonformalin fixed tissue, Nonparaffin embedded tissue, Noncharged slides, ProbeOn slides

Clinical Information

Germinal center B-cell expressed transcript 1 (GCET1), is also known as Centerin and SERPIN9 (serine protease inhibitor). GCET1 is expressed in B cells in the germinal center of normal lymph node and tonsil tissues. Most follicular lymphomas strongly express GCET1. In addition, a proportion of diffuse large B-cell lymphomas (DLBCL) are positive. In the diagnosis of B-cell lymphomas, GCET1 can be useful in an immunohistochemical panel to assign a germinal center phenotype.


This test includes only technical performance of the stain (no pathologist interpretation is performed). Mayo Clinic cannot provide an interpretation of tech only stains outside the context of a pathology consultation. If an interpretation is needed, refer to test code PATHC / Pathology Consultation for a full diagnostic evaluation or second opinion of the case. All material associated with the case is required. Additional specific stains may be requested as part of the pathology consultation, and will be performed as necessary at the discretion of the Mayo pathologist.


The positive and negative controls are verified as showing appropriate immunoreactivity and documentation is retained at Mayo Clinic Rochester. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request. Contact 855-516-8404.


Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.

Clinical Reference

1. Choi WWL, Weisenburger DD, Greiner TC, et al: A new immunostain algorithm classifies diffuse large b-cell lymphoma into molecular subtypes with high accuracy. Clin Cancer Res 2009;15(17):5494-5502

2. Paterson MA, Hosking PS, Coughlin PB, et al: Expression of the serpin centerin defines a germinal center phenotype in b-cell lymphomas. Am J Clin Pathol 2008;130:117-126

3. Montes-Moreno S, Roncador G, Maestre L, et al: GCET1 (centerin), a highly restricted marker for a subset of germinal center-derived lymphomas. Blood 2008;111(1):351-368

Day(s) and Time(s) Performed

Monday through Friday

Analytic Time

1 day

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

88342-TC, primary

88341-TC, if additional IHC

LOINC Code Information

Result ID Test Result Name Result LOINC Value
70755 GCET1 IHC, Tech Only No LOINC Needed