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Test ID BRG1 BRG1 (SMARCA4) Immunostain, Technical Component Only

Ordering Guidance

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

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

Useful For

Diagnosing ovarian small cell carcinoma of hypercalcemic type (SCCOHT)

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

BRG1 (SMARCA4) IHC, Tech Only

Specimen Type


Specimen Stability Information

Specimen Type Temperature Time Special Container
TECHONLY Ambient (preferred)

Clinical Information

BRG1 (SMARCA4) is a member of the switch/sucrose non-fermentable (SWI/SNF) chromatin remodeling complex. Biallelic mutations in BRG1 (SMARCA4) have been reported in ovarian small cell carcinoma of hypercalcemic type (SCCOHT), amongst other tumors. Tumors with these mutations demonstrate a loss of BRG1 protein expression in the nucleus. SCCOHT is difficult to diagnose and loss of BRG1 expression can help in differentiating SSCOHT from its mimics including other primary or metastatic tumors of the ovaries.


This test does not include pathologist interpretation; only technical performance of the stain is performed. If an interpretation is required, order PATHC / Pathology Consultation for a full diagnostic evaluation or second opinion of the case.


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. Clarke BA, Witkowski L, Ton Nu TN, et al: Loss of SMARCA4 (BRG1) Protein Expression by Immunohistochemistry in Small Cell Carcinoma of the Ovary, Hypercalcemic Type Distinguishes these Tumors from their Mimics. Histopathology 2016 Apr 21

2. Conlon N, Silva A, Guerra E, et al: Loss of SMARCA4 Expression Is Both Sensitive and Specific for the Diagnosis of Small Cell Carcinoma of Ovary, Hypercalcemic Type. Am J Pathol 2016;40:395-403

3. Karanian-Philippe M, Velasco V, Longy M, et al: SMARCA4 (BRG1) Loss of Expression Is a Useful Marker for the Diagnosis of Ovarian Small Cell Carcinoma of the Hypercalcemic Type (Ovarian Rhabdoid Tumor). Am J Surg Pathol 2015;39:1197-1205

4. Ramos P, Karnezls A, Craig D, et al: Small Cell Carcinoma of the Ovary, Hypercalcemic Type, Displays Frequent Inactivating Germline and Somatic Mutations in SMARCA4. Nat Genet 2014;46(5):427-430

Day(s) Performed

Monday through Friday

Report Available

1 to 3 days

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

88342-TC, primary

88341-TC, if additional IHC

LOINC Code Information

Test ID Test Order Name Order LOINC Value
BRG1 BRG1 (SMARCA4) IHC, Tech Only Order only;no result


Result ID Test Result Name Result LOINC Value
71541 BRG1 (SMARCA4) IHC, Tech Only Bill only; no result


If not ordering electronically, complete, print, and send a Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request (T763) with the specimen.

Testing Algorithm

For the initial technical component only immunohistochemical (IHC) stain performed, the appropriate bill-only test ID will be reflexed and charged (IHTOI). For each additional technical component only IHC stain performed, an additional bill-only test ID will be reflexed and charged (IHTOA).

Mayo Clinic Laboratories | IHC Catalog Additional Information: