Muscle Biopsy is a medical procedure used to diagnose diseases involving muscles. A tiny piece of muscle is removed from the muscle then processed in the laboratory, and viewed microscopically. The tissue sample is obtained by the doctor who will make an incision in the skin (open biopsy) and remove 3–4 very small pieces of designated muscle.
The muscle which is selected for the biopsy depends on the location of symptoms, which may include pain or weakness. The muscles often selected for sampling are the biceps (an upper arm muscle) or quadriceps (a thigh muscle).
Reasons for having Muscle Biopsy:
A muscle biopsy is performed to assess the musculoskeletal system for abnormalities. Different types of disease related treatments can cause pain or muscle weakness. These sort of conditions can be related to problems within the nervous system, connective tissue, vascular system, or musculoskeletal system.
There may be other reasons for doctor to recommend a muscle biopsy
A muscle biopsy helps to determine the source of the disease process, making it possible to manage the process. Given below is a list of some common conditions which can be diagnosed by muscle biopsy:
A broad term that describes a genetic/inherited disorder of the muscles. Muscular dystrophy makes the muscles in the body to become very weak. The muscles break down and are replaced with fatty deposits over time. There are many different types of muscular dystrophies.
- Metabolic, toxic, mitochondrial myopathies
These muscle disorders are caused due to specific enzyme defects, exposure to toxins including certain medications, and abnormalities of the mitochondria.
A disease that causes inflammation of many of the skeletal muscles.
A multisystem disorder that causes inflammation of the skin, muscles and subcutaneous tissues often resulting in muscle weakness.
Malfunctioning of the motor neurons and nerves can cause muscle atrophy and sometimes muscle biopsies are necessary for diagnosis and management.
Risks associated with Muscle Biopsy
As with any surgical procedure, complications can occur. Some possible complications may include, but are not limited to, the following:
- Bruising and discomfort at the biopsy site
- Bleeding from the biopsy site
- Infection of the biopsy site
There may be some other risks depending on the patient’s specific medical condition. Be sure to discuss any concern with the doctor prior to the procedure.
Stages of Muscle Biopsy
Before Muscle Biopsy-
- The doctor will explain the procedure to the patient and offer him the opportunity to ask any questions that he might be having about muscle biopsy.
- The patient will be asked to sign a consent form that provides permission to perform the procedure. Read the form carefully and ask questions if something is not clear.
- Notify the doctor if the patient is sensitive to or is allergic to any medications, latex, tape, and anesthetic agents (local and general).
- Notify the doctor about all medications (prescribed and over-the-counter) and herbal supplements that the patient is taking.
- Let the doctor know if the patient is having a history of bleeding disorders or if he is taking any anticoagulant (blood-thinning) medications, aspirin, or other medications that affect blood clotting. It may be necessary for the patient to stop these medications prior to the procedure.
- The patient will need to arrange for someone to drive him home after the procedure.
During Muscle Biopsy-
A muscle biopsy is typically performed on an outpatient basis. Procedures may vary depending on the condition and physician’s practices.
This routine generally followed:
- The patient will be asked to remove clothing and will be given a gown to wear.
- During Muscle Biopsy, the patient will need to lie as still as possible.
- The skin over the biopsy site will be cleansed with an antiseptic solution.
- As the physician injects a local anesthetic to numb the area, the patient will feel a needle pricking and a brief stinging sensation.
- The doctor will close the opening in the skin with stitches and adhesive strips.
- A sterile bandage/dressing will be applied.
- The muscle tissue sample will be sent to the laboratory for processing and examination.
After Muscle Biopsy-
- As the patient reaches home, it is important to keep the biopsy area clean and dry.
- As self-absorbing stitches are used, they will not be removed by anyone. Adhesive strips generally will fall off within a few days.
- The biopsy site may be tender or sore for two to three days after a muscle biopsy. Take a pain reliever for soreness as recommended by the doctor. Aspirin or certain other pain medications may increase the chance of bleeding. Be sure to take only recommended medications.
- Notify the doctor to report any of the following:
- Drainage from the biopsy site
- Increased pain around the biopsy site
- The patient may resume his usual activities as instructed by the physician. Usually, the patient will be required not to strain the biopsied leg for 2–3 days.
Processing of the Muscle Biopsy
The muscle biopsy is processed and examined under a microscope. Various types of tests are performed depending on the suspected diagnosis. The processing can take at least one week or more. This is followed by detailed analysis leading to a full report, which may take up to three to four weeks.
The result is sent to the referring doctor, who will then explain the findings to the patient. Any sample remaining after this analysis is stored in case further analysis or re-analysis is required in the future.
Which are the different tests that have to be performed before muscle biopsy?
Some of the different tests which have to be performed before Muscle Biopsy are:
3.    Computed Tomography