A muscle biopsy involves removal of a plug of tissue usually by a needle to be later used for examination. Sometimes more than one needle insertion may be needed to obtain a large enough specimen. If there is a patchy condition expected an open biopsy may be used. Open biopsy involves a small incision through the skin and into the muscle, so that a sample of muscle tissue can be removed from the affected area. There may be some slight bruising or bleeding at the site but the risks are minimal with the procedure.
Review Date 7/10/2018
Updated by: Gordon A. Starkebaum, MD, ABIM Board Certified in Rheumatology, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.