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.
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.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
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 Instructions.
Necessary Information
All requisition and supporting information must be submitted in English.
Each of the following items 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 provider
-Anatomic site and collection date
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: Prepare and transport specimen per instructions in Muscle Biopsy Specimen Preparation Instructions.
Additional Information:
1. All specimens and additional paperwork must be labeled with:
-Two patient identifiers (first and last name, date of birth, or medical record number)
-Pathology accession/case number
-Anatomic site
2. Contact the Mayo Clinic Muscle Laboratory at 800-533-1710 for special problems to maximize benefit of the muscle biopsy.
Acceptable:
Specimen Type: Stained muscle biopsy slides
Collection Instructions:
1. Submit all stains performed on the case.
2. All specimens must be labeled with anatomic site.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Forms
Muscle Histochemistry Patient Information (T361) is required.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
1.5 cm biopsy
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
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, and 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 and 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).
The 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 Instructions. 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, 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;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;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;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;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;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;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;30(3):236-240
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
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.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
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 account representative. 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 was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
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.
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 |