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.
Biopsy - muscle
biopsy is a procedure involving the removal and examination
of a piece of muscle tissue.
How the test
biopsy can usually be obtained while you are awake and the
area being biopsied is numbed by local anesthesia. A needle
biopsy may be adequate in children and adults with chronic
conditions. In this procedure, a needle in inserted into the
muscle. A small "plug" of tissue remains in the needle when
it is removed from the muscle. This tissue is sent to a
pathologist for examination. More than one needle insertion
may be needed to obtain a large enough specimen for testing
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.
A muscle that
has recently been traumatized, such as by an EMG needle, or
that is affected by pre-existing condition, such as nerve
compression, is not a good choice for a biopsy.
chosen for biopsy must be appropriate for the symptoms or
prepare for the test
No fasting or
other special preparation is usually necessary. You may be
asked to wear loose clothing or a hospital gown so that the
muscle chosen for biopsy is easily accessible.
You must sign
an informed consent form.
How the test
biopsy, there is usually minimal or no discomfort. You may
feel some pressure or "tugging" sensations.
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
biopsy may be performed for many reasons, including the
To distinguish between neurogenic (nerve)
and myopathic (primarily muscle) disorders
To identify specific muscular disorders
such as muscular dystrophy or congenital myopathy
To identify metabolic defects of the
To diagnose diseases of the connective
tissue and blood vessels (such as polyarteritis nodosa)
To diagnose infections that affect the
muscles (such as trichinosis or toxoplasmosis)
and related tissue anatomy. A microscopic examination with
and without staining that shows no abnormalities is normal.
biopsy can reveal conditions such as the following:
Atrophy (loss of muscle mass)
Necrosis (tissue death) of muscle fibers
Inflammation of the muscle
Myopathic changes (destruction of the
Muscular dystrophy, indicated by antibody
staining of the muscle biopsy specimen that can show
Traumatic muscle damage
Duchenne's muscular dystrophy
conditions under which the test may be performed include the
Becker's muscular dystrophy
Charcot-Marie-Tooth disease (hereditary)
Common peroneal nerve dysfunction
Facioscapulohumeral muscular dystrophy (Landouzy-Dejerine)
Familial periodic paralysis
Senile cardiac amyloid
Thyrotoxic periodic paralysis
The risks are
minimal and may include the following: