Muscle Biopsy Procedure: Frequently Asked Questions
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Because it is an invasive procedure, muscle biopsy is appropriate for the diagnosis of serious muscle disease such as:
- Myositis
- Muscular Dystrophy
- Toxic Myopathies
- Vasculitis
Muscle biopsy is performed under local anesthesia and is an outpatient procedure typically completed in one hour or less. Patients can expect to spend half a day or longer at the outpatient center in preparation and follow-up for the procedure.
Surgeons at any hospital or surgical facility who are familiar with diagnostic muscle biopsy procedures can obtain a specimen, which then should be sent directly to the Neuromuscular Pathology Laboratory for staining and interpretation.
Biopsies can also be performed at the Johns Hopkins Outpatient Center and for inpatients at The Johns Hopkins Hospital. Patients can expect to spend one half day or more at the outpatient center in preparation and follow-up for the procedure. The tissues obtained at the time of biopsy are prepared in the Neuromuscular Pathology Laboratory at Johns Hopkins.
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Muscle tissue obtained at biopsy is prepared for both frozen and paraffin sectioning at Johns Hopkins. Frozen sections of muscle tissue are routinely prepared using numerous different histochemical stains.
The standard staining battery on frozen tissue includes:
- H&E
- Modified Gomori trichrome
- Acid phosphatase
- Alkaline phosphatase
- Esterase
- ATPase (pH 9.4, 4.6, and 4.3)
- NADH
- COX/SDH
- Congo red
- PAS (with and without diastase)
- Phosphofructokinase
- Myophosphorylase
- Sudan black
Paraffin embedded sections are done routinely and stained with H&E and when indicated with Congo red.
Immunohistochemical staining is available for:
- C5b-9
- CD 3
- CD 8
- CD 20
- CD 68
- MHC-1
Additional muscle tissue is routinely archived for future analyses.
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Patients undergoing nerve or muscle biopsy will receive instructions in advance. Our staff will secure a patient’s insurance authorization once the appropriate referral forms have been completed.
Patients should not take aspirin, aspirin-containing products, or nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen for 10 days prior to the procedure.
Patients taking Coumadin, Lovenox, Plavix or Ticlid will need to follow specific instructions relating to these medications. -
Patients who have a biopsy in the leg must expect to use crutches or another assistive device for two full days after biopsy. Training with crutches is provided. Because of this, some patients may require assistance at home during the recuperation period.
Patients who have a biopsy in the arm must expect to wear a sling for two days.
Stitches do not need to be removed but must remain completely dry for two days. In general, there are few complications, and the resulting scar heals well. -
The results of pathological studies are interpreted by designated neuromuscular specialists in the Johns Hopkins Department of Neurology.
After the biopsy, a report on frozen or paraffin specimens will be sent to the referring physician, generally within one to two weeks. A report on plastic nerve specimens will be provided in three to four weeks.
If you have any questions or concerns, please contact 410-614-4278.
Protocol for Sending Muscle Biopsy Specimens
Notify the Lab
Please notify the Neuromuscular Pathology Laboratory two days in advance that a muscle specimen will be arriving. Please contact:
Christopher Dorsey, Histology Technician:
410-608-3902 (tele)
410-283-5090 (pager)
[email protected],
[email protected], or
Thomas E. Lloyd, MD, PhD, Lab Director:
410-955-2227 (tele)
[email protected]
Obtain the Specimen
A surgeon familiar with the diagnostic muscle biopsy procedure should obtain the specimen. Three strips of muscle approximately 2.5 cm x 0.5 cm parallel to the direction of the muscle fibers should be obtained. A muscle that is moderately but not severely weak should be used for the biopsy (4/5 on the British Medical Research Council Scale).
Electron microscopy of muscle is not routinely done but rarely indicated. If electron microscopy is requested, please contact Dr. Thomas E. Lloyd or Dr. Ahmet Hoke at 410-955-2227 before the biopsy is done as the tissue must be fixed in a special fixative at the time of the biopsy.
Send the Specimen
It is preferable that the specimen be delivered fresh within one hour after excision. If this is possible, wrap the muscle in a piece of saline-moistened gauze and place it in a container or plastic bag. DO NOT IMMERSE BIOPSY SAMPLES IN SALINE. Place in a styrofoam container with regular ice and send immediately by special messenger to:
Neuromuscular Pathology Laboratory
Johns Hopkins Hospital
600 N. Wolfe Street
Meyer Building Room 5-119
Baltimore, MD 21287-7519
Phone: 410-614-4163
Please notify us when to expect the specimen. The following information will be needed. Tissue samples cannot be processed unless this information is provided with the specimen.
- Patient's name, address, date of birth, and hospital ID number
- Hospital charge number for billing directly to the hospital
- Brief clinical history
- Identification of muscle biopsy site, date, and time
- Name, address, phone and fax # of referring pathologist and attending physicians
Specimen Freezing Procedure
If the specimen cannot be delivered in one hour, then it must be frozen immediately after excision, as follows:
- Pour 2-methylbutane (isopentane) into a metal container that will hold a minimum of 200 ml.
- Drop small pieces of dry ice into the liquid to cool it.
- Surround the container with dry ice to keep it cold.
Immediately after excision, the muscle specimen should be stretched in the direction of the fibers to just beyond its in situ resting length, and pinned at each end to a small piece of stiff card (index card). Hold the piece of cardboard with the pinned muscle using a Kelly clamp or pair of forceps, and quickly immerse it in the cold liquid, vigorously shaking the card for 15-20 seconds. This technique disperses bubbles that form around the specimen which would otherwise prevent uniform freezing. When it is thoroughly frozen, pack the specimen in sufficient dry ice and ship overnight to:
Christopher Dorsey
The Neuromuscular Pathology Laboratory
Johns Hopkins Hospital
600 N. Wolfe Street
Meyer Building Room 5-119
Baltimore, MD 21287-7519
Phone: 410-608-3902
[email protected]