Skip navigation

Muscle biopsy

A muscle biopsy is the removal of a small piece of muscle tissue for examination.

How the Test is Performed

This procedure is usually done while you are awake. The health care provider will apply a numbing medicine (local anesthesia) to the biopsy area.

There are two types of muscle biopsy:

A needle biopsy involves inserting a needle into the muscle. When the needle is removed, a small piece of tissue remains in the needle. More than one needle stick may be needed to get a large enough sample.

An open biopsy involves making a small cut in the skin and into the muscle. The muscle tissue is then removed.

After either type of biopsy, the tissue is sent to a laboratory for examination.

How to Prepare for the Test

No special preparation is usually needed. If you will have anesthesia, follow instructions on not eating or drinking anything before the test.

How the Test will Feel

During the biopsy, there is usually little or no discomfort. You may feel some pressure or tugging.

The anesthetic may burn or sting when injected (before the area becomes numb). After the anesthetic wears off, the area may be sore for about a week.

Why the Test is Performed

A muscle biopsy may be done to identify or detect:

A muscle biopsy may also be done to tell the difference between nerve and muscle disorders.

A muscle that has recently been injured, such as by an EMG needle, or is affected by a pre-existing condition, such as nerve compression, is not a good choice for a biopsy.

Normal Results

A normal result means the muscle is normal.

What Abnormal Results Mean

A muscle biopsy can help diagnose the following conditions:

Additional conditions under which the test may be performed include:

Risks

The risks are small, but may include:

  • Bleeding
  • Bruising
  • Damage to the muscle tissue or other tissues in the area (very rare)
  • Infection (a slight risk any time the skin is broken)

Alternative Names

Biopsy - muscle

References

Shepich JR. Muscle biopsy. In: Pfenninger JL, Fowler GC, eds. Pfenninger & Fowler's Procedures for Primary Care. 3rd ed. Philadelphia, PA: Elsevier Mosby; 2010:chap 228.

Update Date: 9/8/2014

Updated by: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

A.D.A.M Quality Logo

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2014, A.D.A.M., Inc. Duplication for commercial use must be authorized in writing by ADAM Health Solutions.

A.D.A.M Logo