Test Code NF2 Merlin (NF2) 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 "Attention Pathology" address label (T498) and the pink Immunostain Technical Only label included in the kit to the outside of the transport container.
Specimen Required
Specimen Type: Tissue
Supplies: Immunostain Technical Only Envelope (T693)
Container/Tube: Immunostain Technical Only Envelope
Submit:
-Formalin-fixed, paraffin-embedded tissue block
OR
-2 Unstained, positively charged glass slides (25- x 75- x 1-mm) per test ordered; sections 4-microns thick
Useful For
The distinction of reactive mesothelial proliferation from mesothelioma
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
IHTOI | IHC Initial, Tech Only | No | No |
IHTOA | IHC Additional, Tech Only | No | No |
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).
Method Name
Immunohistochemistry (IHC)
Reporting Name
Merlin (NF2) IHC, Tech OnlySpecimen Type
TECHONLYSpecimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
TECHONLY | Ambient (preferred) | |
Refrigerated |
Interpretation
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. 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. Offin M, Yang S, Egger J, et. al. Molecular characterization of peritoneal mesotheliomas. J Thorac Oncol.2022; 17(3): 455-460
2. Chapel DB, Hornick JL, Barlow J, et. al. Clinical and molecular validation of BAP1, MTAP, P53, and Merlin immunohistochemistry in diagnosis of pleural mesothelioma. Mod Pathol. 2022;35(10):1383-1397
3. Collins K, Hwang M, Antic T, et. al. Merlin immunohistochemistry is useful in diagnosis of tumours within the spectrum of biphasic hyalinizing psammomatous renal cell carcinoma. Histopathology 2022;81(5):577-586
4. Martin SD, Cheung S, and Churg A. Immunohistochemical demonstration of Merlin/NF2 loss in mesothelioma. Mod Pathol. 2023;36(1): 100036
Day(s) Performed
Monday through Friday
Report Available
1 to 3 daysPerforming Laboratory

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
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
622011 | Merlin (NF2) IHC, Tech Only | No LOINC Needed |
Forms
If not ordering electronically, complete, print, and send a Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request (T763) with the specimen.