Muscle Biopsy

About This Test

A muscle biopsy is a procedure often used to diagnose neuromuscular disorders or diseases involving muscle tissue.

A needle muscle biopsy offers a less invasive alternative to conventional open muscle biopsies for sampling muscle for clinical and research purposes. There is a very small chance that the tissue obtained in a needle biopsy may not be entirely adequate for evaluation. If that happens, an open biopsy may have to be scheduled on a different day.

How to Prepare

• When you are scheduling the biopsy you will be asked if you have a history of bleeding disorders or if you take any anticoagulant (blood-thinning) medicines. You may need to stop these medicines before the procedure
• You should arrange for someone to accompany you and drive on the day of the procedure
• The doctor performing the biopsy will obtain consent from you and answer questions about the biopsy procedure
• Please tell the doctor if you are sensitive or allergic to any medicines, latex, tape, or anesthetic agents (local and general)
• Your PCP or the doctor that has ordered the muscle biopsy should explain to you why they have ordered this procedure

What to Expect

The area to be biopsied (usually the thigh, calf or upper arm) will be cleaned and sanitized. Then, the doctor will administer a small amount of lidocaine via needle to numb the area, and you will be asked to lie still.

The doctor will make a small incision with a surgical blade, just deep enough to insert the needle and obtain adequate muscle tissue. A specialized hollow needle attached to wall suction will be inserted into the muscle 3 or 4 times to obtain sufficient sample. You may feel some pressure or pulling during the procedure; we will check your comfort before, during and after.

After the sample is obtained pressure will be applied for several seconds, the incision site will be cleaned with antiseptic and closed with steri-strips (thin adhesive bandages often used instead of stitches). The steri-strips will fall off naturally over the next few days. Please do not pull them off. Following the procedure, you will be asked to remain flat for 20 – 30 minutes with biopsied limb slightly elevated.

After Your Test

• You may experience tenderness at and around the site for a few days
• You should take it easy the day of the procedure but may shower. You can return to normal but not strenuous activity the day after
• You should call our office if you have a fever, prolonged bleeding or increased pain around the incision
• Your PCP or the doctor that has ordered the muscle biopsy will receive the results in 3-4 weeks