One-stop laboratory solution for answers on common and challenging cases
The muscle and nerve pathology practice at Mayo Clinic, which is led by neuromuscular neurologists with unmatched expertise in acquired and genetic disorders, is one of the oldest and most well-established in the world. Our experienced muscle and nerve specialists apply their knowledge to correlate pathological findings with clinical presentation and other laboratory test results to confirm the diagnosis of a specific neuromuscular disease.
Mayo Clinic Laboratories’ muscle and nerve consultation, in conjunction with clinical assessment and other laboratory testing, can be crucial for the diagnosis of certain neuromuscular disorders. Our neuromuscular pathologists are available to discuss muscle and nerve biopsy findings with referring clinicians. As practicing clinicians, our pathologists can also evaluate the patient, if desired.
A muscle biopsy is essential for the diagnosis of most acquired muscle diseases and some inherited muscle diseases and can help resolve the meaning of variants of unknown significance (VUS).
Our pathology experts review more than 1,000 muscle biopsies annually and provide unique expertise that extends beyond muscle pathology for all muscle diseases.
Extensive morphological and histochemical studies are performed routinely on every frozen muscle sample.
Pathology reviews correlate muscle biopsy findings with clinical history, electromyography (EMG), antibody, and genetic findings. Additional histochemical and immunohistochemical studies are performed, if needed, to investigate the patient’s disease.
Detection of specific findings triggers further investigations to provide patients with a more definite diagnosis. For example, the detection of amyloid, routinely searched in muscle specimens, automatically triggers amyloid subtyping by mass spectrometry analysis in our Hemopathology Laboratory.
Features of mitochondrial myopathy in the proper clinical context can be followed (if desired by the referring physician) by mitochondrial genetic testing in muscle tissue through our Genetics and Genomics Laboratory.
All nerve biopsy samples are initially divided into three specimens: teased fibers, paraffin, and epoxy sections.
Nerve biopsy samples are divided into multiple sections, and individual fibers are teased further.
Teased fiber preparations are the best way to identify pathology along the length of the nerve, such as axonal degeneration or segmental demyelination.
Mayo Clinic provides specimen kits with instructions for specimen collection and fixation.
High-quality evaluations of paraffin-embedded sections are prepared and reviewed for interstitial abnormalities, including immunohistochemistry.
These processes ensure appropriate diagnosis, compared to less precise processes that result in over-diagnosis of certain conditions, such as segmental demyelination.
