Test Catalog

Test Id : MBX

Muscle Pathology Consultation

Useful For
Suggests clinical disorders or settings where the test may be helpful

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

Highlights

Our consultative practice strives to provide the highest quality diagnostic consultative service, balancing optimal patient care with a cost-conscious approach that supports the rapid turnaround time for diagnostic results.

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial 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
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Name
A short description of the method used to perform the test

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

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Muscle Path Consult

Aliases
Lists additional common names for a test, as an aid in searching

Muscle Biopsy, Enzyme Histochemistry

Muscle Tissue

Skeletal Muscle Tissue

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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.

Specimen Type
Describes the specimen type validated for testing

Varies

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
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Preferred:

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.

 

Acceptable:

Specimen Type: Stained muscle biopsy slides

1. Submit all stains performed on the case.

2. All specimens must be labeled with specimen type.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

1.5 cm biopsy

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Varies Frozen (preferred)
Ambient

Useful For
Suggests clinical disorders or settings where the test may be helpful

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

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Muscle diseases are a heterogeneous group of diseases that cause muscle weakness, muscle pain, elevated creatine kinase. They can be acquired and, potentially, treatable or inherited. A muscle biopsy allows the diagnosis of a specific muscle disease and is helpful for guiding treatment, genetic testing, as well as investigating relevance of genetic variants of unknown significance.

 

The Mayo Clinic Muscle Pathology Laboratory is staffed by neuromuscular neurologists with expertise in the whole spectrum of muscle pathology and complementary clinical competence and research interest in muscle diseases. This unique set of skills ensures the highest quality of diagnostic muscle pathology in the shortest possible time to the patients, regardless of their geographic location.

 

A series of 14 stains is routinely performed on each frozen muscle specimen. Client-submitted and in-house stained slides are reviewed in conjunction with the provided clinical history, electromyography, and other laboratory findings. A variety of ancillary studies are available (eg, immunohistochemistry, immunofluorescence) to aid in establishing the diagnosis. These ancillary studies are most efficiently utilized and interpreted in the context of the morphologic features. Each muscle pathology report includes a description of findings and diagnosis, as well as a comment to facilitate integration of pathological findings with other laboratory and clinical data and to guide subsequent testing (eg, serological or genetic tests).

 

Our goal is to provide the highest quality diagnostic service, while balancing optimal patient care with a cost-conscious approach to solve difficult diagnostic problems.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Interpretation
Provides information to assist in interpretation of the test results

Results are reported in a formal neuromuscular pathology report that includes diagnosis and an interpretive comment, if necessary. The formal pathology report is faxed or sent by mail according to the preference of the referring institution.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Be aware that poor freezing and improper handling of the muscle tissue may hinder the neuromuscular pathologist's interpretation of the biopsy. It is crucial to provide a properly handled muscle specimen. In this regard, see directions for Muscle Biopsy Specimen Preparation sheet. A shipping kit is available, Muscle Biopsy Kit (T541), and is recommended for collecting and shipping muscle specimens. It includes a container for the tissue, collection instructions, the Muscle Histochemistry Patient Information sheet, and a box to ship the specimen.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Engel AG: The muscle biopsy. In: Engel AG, Franzini-Armstrong C, eds. Myology. 3rd ed. McGraw-Hill; 2004:681-690

2. Liewluck T, Sorenson EJ, Walkiewicz MA, Rumilla KM, Milone M: Autosomal dominant distal myopathy due to a novel ACTA1 mutation. Neuromuscul Disord. 2017 Aug;27(8):742-746

3. Engel AG, Redhage KR, Tester DJ, Ackerman MJ, Selcen D: Congenital myopathy associated with the triadin knockout syndrome. Neurology. 2017 Mar 21;88(12):1153-1156

4. Niu Z, Pontifex CS, Berini S, et al: Myopathy with SQSTM1 and TIA1 variants: Clinical and pathological features. Front Neurol. 2018 Mar 19;9:147

5. Nicolau S, Liewluck T, Shen XM, Selcen D, Engel AG, Milone M: A homozygous mutation in GMPPB leads to centronuclear myopathy with combined pre- and postsynaptic defects of neuromuscular transmission. Neuromuscul Disord. 2019 Aug;29(8):614-617

6. Nicolau S, Liewluck T, Tracy JA, Laughlin RS, Milone M: Congenital myopathies in the adult neuromuscular clinic: Diagnostic challenges and pitfalls. Neurol Genet. 2019 Jun 4;5(4):e341

7. Liewluck T, Niu Z, Moore SA, Alsharabati M, Milone M: ACTA1-myopathy with prominent finger flexor weakness and rimmed vacuoles. Neuromuscul Disord. 2019 May;29(5):388-391

8. Nicolau S, Liewluck T, Elliott JL, Engel AG, Milone M: A novel heterozygous mutation in the C-terminal region of HSPB8 leads to limb-girdle rimmed vacuolar myopathy. Neuromuscul Disord. 2020 Mar;30(3):236-240

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Description
Describes how the test is performed and provides a method-specific reference

All requests will be processed as a consultation case first. Special studies will be performed only if deemed to be diagnostically indicated. Histochemical and immunohistochemical stains are only performed if frozen muscle biopsy tissue is provided.(Unpublished Mayo method)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

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

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

6 months

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

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® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
MBX Muscle Path Consult 60570-9
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
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
601822 Case Number 80398-1
601911 Disclaimer 62364-5
603614 Material Received 81178-6

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports