Biopsy of muscle

For this test, a piece of the muscle is collected. The muscle tissue is examined and used to evaluate and manage suspected neuromuscular diseases including congenital myopathy.

Laboratory tests may be done for many reasons. Tests are performed for routine health screenings or if a disease or toxicity is suspected. Lab tests may be used to determine if a medical condition is improving or worsening. Lab tests may also be used to measure the success or failure of a medication or treatment plan. Lab tests may be ordered for professional or legal reasons. You may need this test if you have:

• Benign congenital myopathy
• Dermatomyositis
• Inclusion body myositis
• Inflammatory disorder of muscle
• Metabolic myopathy
• Muscular dystrophy
• Polymyositis
• Spinal muscular atrophy

A muscle biopsy is a procedure that requires your written consent. Review the consent form with the healthcare worker and ask any questions that you have before signing the consent form. You may need to have other tests done before having a muscle biopsy.

Tell the healthcare worker if you have a medical condition or are using a medication or supplement that causes excessive bleeding. Report any past or present muscle diseases or conditions, and if any of your muscles have had previous medical treatments. Tell the healthcare worker if you have a history of allergic or other reactions to local anesthetics.

One or more muscles will be selected for a muscle tissue biopsy. The vastus lateralis (a muscle of the upper leg) is the muscle most often selected for biopsy. However, the reasons for choosing certain muscles or areas on the muscle vary widely. Muscle selection depends on the type of test, disease suspected, and many other factors. There are several different ways that a biopsy may be performed. A needle biopsy is used to obtain a small sample of muscle tissue. An open biopsy is used to collect a larger muscle sample.

An open biopsy is a surgical procedure. A regional block or general anesthetic may be used for sedation during this procedure. After you are sedated, the biopsy area will be cleaned and prepared for the procedure. During an open biopsy, an incision will be made over or near the muscle to be biopsied. The muscle tissue sample will be collected, and the incision closed.

Before a needle biopsy, local anesthetic will be injected in the procedure area. This medication makes the area numb. A needle will be advanced through the skin and fat layers, and into the muscle. The muscle may be squeezed toward the needle. The needle may be moved in and out, and then removed with the muscle tissue sample.

During the procedure, one or more incisions may be made, and multiple sections of tissue removed. Over time, you may need to have more muscle tissue samples taken. Muscle samples may also be taken on infants before or after they are born.

The amount of discomfort you feel will depend on many factors, including your sensitivity to pain. Communicate how you are feeling with the person doing the procedure. Inform the person doing the procedure if you feel that you cannot continue with the procedure.

Before a needle biopsy into a muscle, local anesthetic is given to the procedure site to numb the area. You may feel mild discomfort or stinging when the numbing medicine is injected. You may still be able to feel pressure or discomfort. For an open muscle biopsy, an anesthesiologist will give you a general or regional anesthetic. During general anesthesia you receive medicine that puts you into a deep sleep where you are unable to feel pain. With regional anesthesia or a block, you receive medicine that numbs a nerve or group of nerves that supply a certain area of your body. With a regional anesthetic, you are awake but will not feel pain or pressure in the numbed area. For a muscle biopsy, you may experience discomfort in the area for several days.

After a muscle tissue biopsy, bandages and/or sterile tape may be secured over the incision. Follow the instructions given to you by the healthcare worker regarding changing bandages and caring for the wound or wounds. The biopsy site may be painful for about a week after the procedure. Contact healthcare workers if you see increasing redness, swelling or pus at the procedure site, or for increased pain or new loss of feeling (numbness) in an area.

You have the right to help plan your care. To help with this plan, you must learn about your health condition and how it may be treated. You can then discuss treatment options with your caregivers. Work with them to decide what care may be used to treat you. You always have the right to refuse treatment.