Muscle Biopsies

The Muscle Pathology service at UT Health San Antonio provides expert pathology assessment of muscle biopsies.  Our service provides accurate, timely diagnosis services to aid in the identification of diseases affecting the muscle.  Light microscopy and frozen muscle enzyme studies are utilized in each case to arrive at the most precise diagnosis possible.   Consultative opinions are available upon request.

Muscle Biopsy Preparation

  • Please notify the Histopathology Laboratory (210)567-6599, two days in advance that a muscle specimen will be arriving.
  • A surgeon familiar with the diagnostic muscle biopsy procedure should obtain the specimen. Three strips of muscle approximately 2.5 cm x 0.5 cm parallel to the direction of the muscle fibers should be obtained. A muscle that is moderately but not severely weak should be used for the biopsy.
  • It is preferable that the specimen be delivered fresh within one hour after excision. If this is possible, wrap the muscle in a piece of saline-moistened gauze and place it in a container or plastic bag. DO NOT IMMERSE BIOPSY SAMPLES IN SALINE. Place in a styrofoam container with regular ice and send immediately by courier to:

UT Health San Antonio
Department of Pathology & Laboratory Medicine
Histopathology—Room 344B-MED
7703 Floyd Curl Dr.
San Antonio, Texas 78229
Phone #: (210)567-6599

Please notify us when to expect the specimen

  • If the specimen cannot be delivered in one hour, then it must be frozen immediately after excision, as follows:
    • Freezing the muscle biopsy can be successfully achieved in 10-30 seconds.
    • Using 50-75 ml of fresh chilled 2-methylbutane (isopentane) chilled to – l30ºC (check with a low-grade temperature thermometer) in a plastic beaker slowly lowered into a dewar flask filled with liquid nitrogen. Small white plaque forms on the bottom and sides of the beaker at approximately -100º C.
    • Do not allow the liquid nitrogen to bubble into the isopentane.
    • Carefully picking up the coated biopsy with forceps, lower it into the -l30ºC isopentane, wearing freezer gloves to protect your hands.
    • Depending on the muscle measurement the biopsy is flash frozen in l0-30 seconds.
    • Remove the biopsy from the plastic freezer container. The flash frozen biopsy must not be allowed to thaw. When it is thoroughly frozen, pack the specimen in sufficient dry ice (always take into consideration the Texas temperatures) and ship overnight to:

UT Health San Antonio
Department of Pathology & Laboratory Medicine
Histopathology–Room 344B-MED
7703 Floyd Curl Dr.
San Antonio, Texas 78229
Phone#: (210) 567-6599

  • The following information will be needed.  Tissue samples cannot be processed unless this information is provided with the specimen.
    • The patient’s first and last name, a second identifier, site/laterality, and the collection date must be present on all specimen containers.
    • The information on the container must match the requisition.
    • Complete all the information on the Laboratory Request Form.
    • Send a copy of the patient’s medical history and current relevant lab results. Be sure to include the name and contact information of the referring physician.