MUSCLE AND NERVE BIOPSY PROTOCOL
St. Mary’s Hospital Laboratory – Department of Pathology
I. Before doing a Muscle &/or Nerve Biopsy:
1. Before performing a muscle or nerve biopsy, please inform the surgical pathology laboratory
(608-258-6929) so that a proper procedure of muscle examination can be followed.
2. The surgeon or attending physician should complete the clinical information form.
3. The requesting physician or surgeon can discuss clinical questions with Dr. Oliver Ni, the
muscle and nerve pathologist at (608) 260-2500, if needed.
4. It is most feasible to perform a muscle and or nerve biopsy in AM to insure delivery and
proper processing of the specimen at St. Mary’s.
II. Selection of Muscle:
1. The muscle selected for the biopsy should be a moderately involved muscle. Minimally
involved muscle is more likely to be non-diagnostic. Severely involved muscles are more
likely to show end-stage disease which can at times be uninterpretable.
2. The muscle biopsy should not be obtained from a muscle that has been evaluated
electromyographically. Needle EMG’s induce the artefact of an inflammatory reaction. If an
EMG shows myopathic findings on the right deltoid, a biopsy of the left deltoid would be
appropriate. If an EMG shows myopathic findings on the vastus medialis, a biopsy of the
vastus lateralis would be appropriate.
III. Procedure of Obtaining Muscle and/or Nerve:
1. When Xylocaine (without adrenaline) is used for anaesthesia, it should be delivered to the
subcutaneous tissue only. It is important not to infiltrate the muscle itself. The aim of the
biopsy is to isolate a portion of the muscle with as little trauma as possible, and not induce any
artefact.
2. Make the incision to open the facia parallel to the muscle fiber orientation. Avoid excessive
traumatization to the muscle. Even minimal trauma can induce an inflammatory reaction as
well as give the appearance of necrosis or degeneration. Do not use cautery, sutures, or
clamps.
3. Obtain two separate pieces of muscle:
A.
Piece one: 1.5 cm X 0.8 cm X 0.8 cm. This if for light microscopy and
histochemistry.
B.
Piece two: 1.5 cm X 0.8 cm X 0.8 cm. This is for electron microscopy.
4. Obtain one section of involved nerve at least 2.5 cm in length.
IV. Transportation of Specimen:
1. Place the muscle or nerve biopsy specimens on gauze slightly moistened with normal saline
in a specimen container. The gauze should not be damp-soaked wet. To avoid freezing
artifact, please do not rinse nor immerse in saline!
2. Put specimen container on ice in a closed container.
3. Notify St. Mary’s lab that the specimen is on its way (608-258-6929).
4. Transport the specimen to the surgical pathology lab at St. Mary’s Hospital immediately!
V. Fill out Clinical Information Data Sheet and Send with Biopsy.
VI. Call the Surgical Pathology Lab at 608-258-6929 if there are any questions.
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