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Test ID MUM1B MUM-1/IRF4 Immunostain, Bone Marrow, 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 slides (25- x 75- x 1-mm) per test ordered; sections 4-microns thick; B5 fixed, decalcified, paraffin-embedded bone marrow tissue

Acceptable: B5 fixed, decalcified, paraffin-embedded bone marrow tissue block


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

Useful For

Aiding in the identification of hematolymphoid neoplasms and melanomas

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

Bone Marrow MUM-1/IRF4 IHC, T Only

Specimen Type


Specimen Stability Information

Specimen Type Temperature Time Special Container
TECHONLY Ambient (preferred)

Clinical Information

MUM-1 (multiple myeloma oncogene-1), expressed by the IRF4 gene, is seen in a subset of B cells in the light zone of the germinal center (representing late stages of B cell differentiation), plasma cells, activated T cells, and a variety of hematolymphoid neoplasms derived from these cells. Among non-hematolymphoid neoplasms, MUM-1 expression has been reported in melanomas. A separate protocol optimized for B5 fixed/decalcified bone marrow specimens has been validated.


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. Rada G, Nagla S, Ali G: MUM1 and Ki67 Expression Best Predictors of Treatment Response in Diffuse Large B Cell Lymphoma Not Otherwise Specified. Amer J Clin Pathol 2015 Oct;144(2,1):A147

2. Cozzolino I, Varone V, Picardi M, et al: CD10, BCL6, and MUM1 expression in diffuse large B-cell lymphoma on FNA samples. Cancer Cytopathol 2016;124:135-143. doi:10.1002/cncy.21626

3. Heo MH, Park HY, Ko YH, et al: IRF4/MUM1 expression is associated with poor survival outcomes in patients with peripheral T-cell lymphoma. J Cancer 2017;8(6):1018-1024. doi:10.7150/jca.17358

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
MUM1B Bone Marrow MUM-1/IRF4 IHC, T Only Order only;no result


Result ID Test Result Name Result LOINC Value
603218 Bone Marrow MUM-1/IRF4 IHC, T Only Bill only; no result
Mayo Clinic Laboratories | IHC Catalog Additional Information: