- How is muscle tissue studied at Johns Hopkins?
- Where are the biopsies performed?
- What is the muscle biopsy procedure?
- What do patients need to do before the procedure?
- What happens after the biopsy?
- Who interprets the results?
- When will results be received?
- Are biopsies covered by insurance?
- Is there a doctor or laboratory technician with whom I can directly communicate?
How is muscle tissue studied at Johns Hopkins?
Muscle tissue obtained at biopsy is prepared for both frozen and paraffin sectioning at Johns Hopkins. Frozen sections of muscle tissue are routinely prepared using numerous different histochemical stains. The standard staining battery on frozen tissue includes:
- Modified Gomori trichrome
- Acid phosphatase
- Alkaline phosphatase
- ATPase (pH 9.4, 4.6, and 4.3)
- Congo red
- PAS (with and without diastase)
- Sudan black
Paraffin embedded sections are done routinely and stained with H&E and when indicated with Congo red.
Immunohistochemical staining is available for:
- Sarcoglycans (alpha, delta, & gamma)
- Laminin alpha-2
- Collagen VI
Additional muscle tissue is routinely archived for future analyses.
Where are the biopsies performed?
Surgeons at any hospital or surgical facility who are familiar with diagnostic muscle biopsy procedures can obtain a specimen, which then should be sent directly to the Neuromuscular Pathology Laboratory for staining and interpretation.
Biopsies can also be performed at the Johns Hopkins Outpatient Center and for inpatients at The Johns Hopkins Hospital. Patients can expect to spend one half day or more at the outpatient center in preparation and follow-up for the procedure. The tissues obtained at the time of biopsy are prepared in the Neuromuscular Pathology Laboratory at Johns Hopkins.
What is the muscle biopsy procedure?
Because it is an invasive procedure, muscle biopsy is appropriate for the diagnosis of serious muscle disease. Possible diseases which require assessment by muscle biopsy may include:
Muscle biopsy is performed under local anesthesia and is an outpatient procedure. Typically completed in one hour or less, patients can expect to spend one half day or more at the outpatient center in preparation and follow-up for the procedure.
What do patients need to do before the procedure?
Patients undergoing nerve or muscle biopsy will receive instructions in advance.
Patients should not take aspirin, aspirin-containing products, or nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen for 10 days prior to the procedure.
Patients taking Coumadin, Lovenox, Plavix or Ticlid will need to follow specific instructions relating to these medications.
What happens after the biopsy?
Patients who have a biopsy in the leg must expect to use crutches or another assistive device for two full days after biopsy. Training with crutches is provided. Because of this, some patients may require assistance at home during the recuperation period.
Patients who have a biopsy in the arm must expect to wear a sling for two days.
Stitches do not need to be removed but must remain completely dry for two days. In general there are few complications and the resulting scar heals well.
Who interprets the results?
The results of pathological studies are interpreted by designated neuromuscular specialists in the Johns Hopkins Department of Neurology.
When will results be received?
After the biopsy, a report on frozen or paraffin specimens will be sent to the referring physician, generally within one to two weeks. A report on plastic nerve specimens will be provided in three to four weeks.
Are biopsies covered by insurance?
Our staff will secure a patient’s insurance authorization once the appropriate referral forms have been completed.
Is there a doctor or laboratory technician with whom I can directly communicate?
If you have any questions or concerns, please contact 410-614-4278.