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 7/21/2016
Updated by: Gordon A. Starkebaum, MD, Professor of Medicine, Division of Rheumatology, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.