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Test ID CALPN Calponin 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

Marker for myoepithelium when differentiating ductal carcinomas in situ from infiltrating breast carcinoma


Characterization of tumors of smooth muscle or myoepithelial lineage

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

Immunohistochemistry (IHC)

Reporting Name

Calponin IHC, Tech Only

Specimen Type


Specimen Stability Information

Specimen Type Temperature Time Special Container
TECHONLY Ambient (preferred)

Clinical Information

Calponin is a cytoskeleton-associated protein that can bind to actin, tropomyosin, troponin C, and calmodulin and is involved in modulation of smooth muscle contraction.


Calponin expression has been demonstrated in smooth muscle cells of blood vessels and myoepithelial cells in the lobules, ducts, and galactophorous sinuses of normal human breast.


This test does not include pathologist interpretation; only technical performance of the stain. If 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, call 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. Russell T D, Jindal S, Agunbiade S, et al: Myoepithelial cell differentiation markers in ductal carcinoma in situ progression.  Am J Pathol. 2015;185(11):3076-3089. doi: 10.1016/j.ajpath.2015.07.004

2. Gray E, Mitchell, E, Jindal S, Schedin P, Chang YH: A method for quantification of calponin expression in myoepithelial cells in immunohistochemical images of ductal carcinoma in situ. Proc IEEE Int Symp Biomed Imaging. 2018 Apr;2018:796-799. doi: 10.1109/isbi.2018.8363692

3. Liu R, Jin JP: Calponin isoforms CNN 1, CNN 2 and CNN 3: Regulators for actin cytoskeleton functions in smooth muscle and non-muscle cells. Gene. 2016;585(1):143-153. doi: 10.1016/j.gene.2016.02.040

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
CALPN Calponin IHC, Tech Only Order only;no result


Result ID Test Result Name Result LOINC Value
70683 Calponin 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.

Mayo Clinic Laboratories | IHC Catalog Additional Information: