What is a muscle biopsy?
A muscle biopsy is a procedure used to diagnose diseases involving muscle tissue.
Your healthcare provider will remove tissue and cells from a specific muscle and view
them under a microscope. Your provider will only need to remove a small piece of tissue
from the muscle.
Your healthcare provider takes the tissue sample by inserting a biopsy needle into
your muscle. If a larger sample is required, your healthcare provider may make an
incision in your skin (open biopsy) and remove a larger section of muscle.
The muscle selected for your biopsy depends on the location of symptoms, which may
include pain or weakness. The muscles often selected for sampling are the bicep (upper
arm muscle), deltoid (shoulder muscle), or quadriceps (thigh muscle).
Why might I need a muscle biopsy?
You may need a muscle biopsy to assess your musculoskeletal system for abnormalities.
Various diseases can cause muscle weakness or pain. These conditions may be related
to problems with your nervous system, connective tissue, vascular system, or musculoskeletal
A muscle biopsy helps determine the source of the disease process. This ensures the
Your healthcare provider may do a muscle biopsy to diagnose neuromuscular disorders,
infections that affect your muscle, and other abnormalities in your muscle tissue.
These may include:
Muscular dystrophy (MD). A broad term that describes a genetic (inherited) disorder of the muscles. MD affects
skeletal muscles and other organ systems. When the muscles break down, fatty deposits
replace them over time. There are many different types of MD.
Duchenne muscular dystrophy (DMD). The most common form of MD. DMD usually affects only males.
Becker muscular dystrophy. Similar to DMD this form is usually more mild and symptoms start later in life.
Myasthenia gravis (MG). A complex, autoimmune disorder in which antibodies destroy neuromuscular connections.
This causes problems with the nerves that communicate with muscles. MG affects the
voluntary muscles of the body, especially your eyes, mouth, throat, and limbs.
Polymyositis. A chronic disease involving skeletal muscles.
Dermatomyositis. A collagen disorder that causes inflammation to the skin, muscles, and subcutaneous
tissue, often resulting in weakened muscles.
Amyotrophic lateral sclerosis (ALS). Also known as Lou Gehrig disease. ALS is a disease that attacks the nerves signaling
voluntary muscle movement, eventually causing paralysis.
Friedreich ataxia. An inherited, genetic disorder that involves balance and coordination.
Trichinosis. An infection caused by a parasite that lives in raw meat. Symptoms may include muscle
pain. But a muscle biopsy is rarely done to diagnose trichinosis.
There may be other reasons for your healthcare provider to recommend a muscle biopsy.
What are the risks of a muscle biopsy?
As with any surgical procedure, complications can occur. They may include:
Bruising and discomfort at the biopsy site
Prolonged bleeding from the biopsy site
Infection of the biopsy site
Other risks may exist, depending on your specific health condition. Talk about any
concerns with your healthcare provider before the procedure.
How do I get ready for a muscle biopsy?
Your healthcare provider will explain the procedure to you, and you can ask any questions
you may have.
You will be asked to sign a consent form that gives your permission to do the procedure.
Read the form carefully and ask questions if something is not clear.
In addition to a complete medical history, your healthcare provider may do a complete
physical exam to ensure you are in otherwise good health before undergoing the procedure.
You may have blood tests or other diagnostic tests.
Tell your healthcare provider if you are sensitive or allergic to any medicines, latex,
tape, or anesthetic agents (local and general).
Tell your healthcare provider of all medicines (prescribed and over-the-counter) and
herbal supplements that you take.
Tell your provider if you have a history of bleeding disorders, or if you take any
anticoagulant (blood-thinning) medicines, aspirin, or other medicines that affect
blood clotting. You may need to stop these medicines before the procedure.
If you are pregnant or think you could be, tell your healthcare provider.
You may be asked to fast for several hours before the procedure.
You may receive a sedative before the procedure to help you relax. Because the sedative
may make you drowsy, you will need to arrange for someone to drive you home.
Based on your health condition, your healthcare provider may request other specific
What happens during a muscle biopsy?
Your healthcare provider may do a muscle biopsy on an outpatient basis, or as part
of your stay in a hospital. Procedures may vary, depending on your condition and your
provider’s practices. Generally, a muscle biopsy follows these steps:
You will be asked to remove clothing and will be given a gown to wear.
During the procedure, you will need to lie as still as possible.
A healthcare provider will clean the skin over the biopsy site with an antiseptic
As your healthcare provider injects a local anesthetic to numb the area, you will
feel a needle stick and a brief stinging sensation.
Your healthcare provider will insert the biopsy needle through your numbed skin and
into the muscle to take the sample. You may feel some pressure, or pulling, during
If a larger sample is required, your healthcare provider will make a small incision
into the skin’s surface. Your provider may cut sections of your muscle tissue using
small, sharp scissors instead of a biopsy needle. You may feel mild discomfort when
the muscle is cut.
Your healthcare provider will withdraw the biopsy needle and apply firm pressure to
the biopsy site for a few minutes, until the bleeding has stopped.
Your provider will close the opening in your skin with adhesive strips or stitches,
A healthcare provider will apply a sterile bandage or dressing.
Your provider will send your muscle tissue sample to the lab for exam.
What happens after a muscle biopsy?
Once you are home, it is important to keep the biopsy area clean and dry. Your healthcare
provider will give you specific bathing instructions. If you have stitches, your healthcare
provider will remove them during a follow-up office visit. Keep adhesive strips dry
and they should fall off on their own within a few days.
The biopsy site may be tender or sore for 2 to 3 days after your muscle biopsy. Take
a pain reliever for soreness, as your healthcare provider recommends. Aspirin or certain
other pain medicines may increase your chance for bleeding. Be sure to take only recommended
Tell your healthcare provider if you have:
Redness, swelling, bleeding, or other drainage from the biopsy site
Increased pain around the biopsy site
You may resume your usual diet and activities, unless your healthcare provider advises
you otherwise. Your healthcare provider may restrict your activity for 24 hours following
the procedure and ask that you avoid excessive use of the biopsied muscle.
Your provider may give you other instructions after the procedure, depending on your
Before you agree to the test or the procedure make sure you know:
The name of the test or procedure
The reason you are having the test or procedure
What results to expect and what they mean
The risks and benefits of the test or procedure
What the possible side effects or complications are
When and where you are to have the test or procedure
Who will do the test or procedure and what that person’s qualifications are
What would happen if you did not have the test or procedure
Any alternative tests or procedures to think about
When and how you will get the results
Who to call after the test or procedure if you have questions or problems
How much you will have to pay for the test or procedure