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Test ID MBX Muscle Pathology Consultation

Ordering Guidance

This test is not appropriate for inhalation-transmission diseases such as tuberculosis, Brucella, measles, and varicella zoster. This test is also not appropriate for suspected Creutzfeldt-Jacobs Disease (CJD).

Additional Testing Requirements

Muscle biopsies from different anatomic sites require separate orders and separate specimen vials.

Shipping Instructions

Transport specimen per instructions in Muscle Biopsy Specimen Preparation.

Necessary Information

The following information is required:

1. All requisitions must be labeled with:

-Patient name, date of birth and medical record number

-Name and phone number of the referring pathologist or ordering physician

-Anatomic site and collection date

2. All specimens must be labeled with:

-Two patient identifiers (first and last name, date of birth or medical record number)

-Specimen type and anatomic site

3. Muscle Histochemistry Patient Information must accompany all specimens.

All requisition and supporting information must be submitted in English.

Specimen Required


Specimen Type: Frozen muscle biopsy tissue

Supplies: Muscle Biopsy Kit (T541)

Collection Instructions:

1. Prepare and transport specimen per instructions in Muscle Biopsy Specimen Preparation.

2. Patient history and requests must be clearly labeled with correct patient identifiers and pathology accession/case number.

3. All specimens must be labeled with specimen type.

Additional Information: Contact the Mayo Clinic Muscle Laboratory for special problems to maximize benefit of the muscle biopsy.



Specimen Type: Stained muscle biopsy slides

1. Submit all stains performed on the case.

2. All specimens must be labeled with specimen type.

Useful For

Obtaining a rapid, expert opinion on muscle biopsy specimens for diagnosis of acquired or inherited muscle diseases


Guiding treatment and genetic testing, as well as investigating relevance of genetic variants of unknown significance

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
IHPCI IHC Initial No, (Bill Only) No
IHPCA IHC Additional No, (Bill Only) No
IFPCI IF Initial No, (Bill Only) No
IFPCA IF Additional No, (Bill Only) No
SS2PC SpecStain, Grp II, other No, (Bill Only) No
SS3PC SpecStain, Grp III, enzyme No, (Bill Only) No
HCFPC SpecStain, frozen No, (Bill Only) No
COSPC Consult, Outside Slide No, (Bill Only) No
CSPPC Consult, w/Slide Prep No, (Bill Only) No
CUPPC Consult, w/USS Prof No, (Bill Only) No
CRHPC Consult, w/Comp Rvw of His No, (Bill Only) No
LV4RP Level 4 Gross and Microscopic, RB No, (Bill Only) No

Testing Algorithm

A battery of enzyme histochemical stains will be performed on frozen tissue; additional histochemical stains or immunostains may be performed on frozen tissue; other tests can be performed at an additional charge. The reviewing neuromuscular pathologist will determine the need for additional testing. The patient's provided clinical history, creatine kinase values, and electromyography results are helpful in guiding the additional tests.


For all consultations, ancillary testing necessary to determine a diagnosis is ordered at the discretion of the Mayo Clinic neuromuscular pathologist. An interpretation, which includes an evaluation of the specimen and determination of a diagnosis, will be provided within a formal pathology report.


Frozen tissue sent for consultation: Appropriate additional stains may be performed at an additional charge.


Slides sent for consultation: Special stains and studies performed on the case should be sent with the case for review. In order to determine an accurate diagnosis, some of these stains or studies may be deemed to warrant repeat testing, at an additional charge, at the discretion of the reviewing Mayo Clinic neuromuscular pathologist. The interpreting neuromuscular pathologist may also request frozen tissue to perform additional studies considered necessary for diagnosis.

Note: Testing requested by the referring physician (immunostains, etc) may not be performed if deemed unnecessary by the reviewing Mayo neuromuscular pathologist. Electron microscopic studies are not performed on muscle biopsy specimens. For more information see Why Electron Microscopy is Not Performed on Muscle Biopsy Specimens.


For more information see Pathology Consultation Ordering Algorithm.

Method Name

Muscle Biopsy Surgical Pathology Consultation and/or Review of Outside Material

Reporting Name

Muscle Path Consult

Specimen Type


Specimen Minimum Volume

1.5 cm biopsy

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Frozen (preferred)

Reference Values

An interpretive report will be provided.

Day(s) Performed

Monday through Friday

Report Available

3 to 14 days; Cases requiring additional material or ancillary testing may require additional time.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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 (if appropriate)

88341 (if appropriate)

88346 (if appropriate)

88350 (if appropriate)

88305 (if appropriate)

88313 (if appropriate)

88319 (if appropriate)

88314 (if appropriate)

88321 (if appropriate)

88323 (if appropriate)

88323-26 (if appropriate)

88325 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
MBX Muscle Path Consult 60570-9


Result ID Test Result Name Result LOINC Value
601767 Interpretation 59465-5
601769 Participated in the Interpretation No LOINC Needed
601770 Report electronically signed by 19139-5
601771 Addendum 35265-8
601773 Gross Description 22634-0
603614 Material Received 81178-6
601822 Case Number 80398-1
601911 Disclaimer 62364-5