The submission of a high-quality sample is a crucial component for a successful pathologic evaluation. In addition to the submission of well-preserved samples of high diagnostic quality, it is equally important to provide a thorough clinical history. In some cases, photographs of lesions are also helpful. Furthermore, close contact with the pathologist reading the biopsy sample is instrumental to a high-quality diagnosis and prognostic evaluation. At the MSU VDL, we strive to provide our clients with the highest quality service, and guarantee direct communication between our pathologists and our clients. We encourage our clients to talk to us on the phone, inquire about preparation of samples and additional testing available at the laboratory, and discuss diagnosis and clinical implications. The most important facts about sample submission are summarized here.

Specimen Fixation

Place tissue in fixative as soon as possible.

Preferred fixative is 10% neutral buffered formalin. Tissue to formalin ratio should be 1:10. If formalin is not available, the tissues should be refrigerated and shipped cold. Do not freeze.

Specimens should ideally be no thicker than 1 cm. However, for large specimens, we prefer that they are submitted intact (see below for tips for handling large specimens).

Fix tissues for 24-48 hours.

Tissues may also be fixed in formalin for 24-48 hours, removed from the solution, wrapped in formalin-soaked gauze sponges, and placed in a leak-proof plastic bag for shipment.

Please contact the laboratory for special fixation considerations (alternative fixatives; fixation of globes, nails, hooves, etc.).

To avoid freezing artifacts of the specimens when shipped in very cold weather, use an insulated shipping container, and/or substitute one part isopropyl alcohol in the formalin fixative.

If the size or density of the specimen requires incision in order to ensure complete fixation, care should be taken to incise the specimen at the surface (ie. haired skin surface in cutaneous masses) rather than at the deep/surgical margin.

If needed (e.g. the specimen is very large, full margin evaluation is desired, the specimen is oddly shaped), describe (or draw) any identifying characteristics of the specimen (i.e. ink, suture, staple, scar, etc.). This allows for communicating the orientation of the specimen between the clinician, histotechnician, and pathologist.

Very small specimens should be placed in a tissue cassette +/- foam pads to prevent specimen loss.

Specimen Information

Providing complete patient information will aid interpretation of lesions. This information will ideally include:

  • Patient signalment: species, breed, age, sex
  • Patient’s pertinent clinical history
  • Description, duration and distribution of lesion(s); photographs are always welcome
  • Previous biopsy information (accession number, copy of biopsy report, etc.)
  • Anatomic location of lesion
  • Description of identifying characteristics such as inked margins or suture placement for proper identification and/or orientation of the specimen
  • Number of tissues included in the submission

Biopsy specimens should be accompanied by the appropriate MSU VDL Biopsy submittal form.

Additional Specimen Types

Histologic slides or tissue in paraffin blocks may also be submitted to the laboratory for biopsy examination (consultation), immunohistochemistry, or special staining.

Our laboratory also offers GLP services for routine histology including evaluation by a pathologist and provides various types of special services (e.g. laser capture microdissection, in-situ hybridization, immunohistochemistry, electronmicroscopic preparation and evaluation, etc.) for researchers and pharmaceutical companies.

Shipping Biopsy Specimens

Formalin fixation of the tissue precludes the need for rapid transport of specimens to the diagnostic laboratory. However, in order to facilitate receiving biopsy results in a timely manner and to allow for ancillary testing such as immunohistochemistry (fixation in formalin should be less than two days), the use of an overnight carrier service is recommended.

Biopsy mailers are one of the Shipping Solutions offered by the MSU VDL. These mailers contain biopsy jars but NOT formalin, to safely and quickly ship your biopsy specimens to the MSU VDL. They are available as small (two biopsy jars) or large (four biopsy jars). Small biopsy mailers are available with overnight UPS delivery or USPS mail delivery; large biopsy mailers are available with overnight UPS delivery only.

Multiple Tissues or Tumors

Oncologic pathology has always been one of the mainstays of the biopsy service. To provide an accurate diagnosis and prognosis, we recommend that every surgically removed mass be submitted for pathologic examination. If an animal presents with multiple masses, each of these masses should be examined to guarantee an accurate diagnosis and prognosis.

To provide our clients with high quality, price competitive services, VDL will accept multiple biopsies that were taken at the same time from the same animal as a single case submission. There will only be a small additional charge for each additional tumor rather than a full biopsy charge. Please refer to our catalog of available tests for additional information regarding the submission of multiple tissue/tumor charges.

Please be sure to indicate the individual tumor site and lesion description where possible. If the tissue specimens are to be submitted in the same formalin container, identifying individual masses through the use of different colored inks, sutures, surgical staples, etc. is recommended. Multiple tissue charges do not apply to cases for which multiple skin biopsies are submitted for dermatologic conditions, or where multiple gastrointestinal biopsies are submitted from the same animal. For cases that include multiple other organs in the same submission, there will be an additional charge for a total of 4-5 tissues, followed by an additional charge for each 2-3 added tissues. For field necropsy cases that include both fixed and fresh tissue for diagnostic testing please see field necropsy information provided in our Necropsy Service.

Frozen Specimens

The histopathology service offers the preparation of frozen sections and our pathologists can perform microscopic evaluation of these sections. We have a state-of-the-art cryostat system with a tape-transfer system for higher quality sections. Frozen sections can be produced for research, but are also useful for fast turn-around and immunohistochemistry using antibodies that do not work in formalin-fixed sections (e.g. those used for histiocytic diseases). Commonly requested immunohistochemistry markers which require frozen tissue samples, rather than formalin-fixed tissue, include: CD4, CD8, CD11a, and CD11c.

Also see:

Preparation of Cytologic Samples for Immunocytochemistry

Standard Trimming Method

Complete Surgical Margin Evaluation (includes instructions for inking margins)

Submitting Special Tissues (e.g. bone, bone marrow, tooth, nail, hoof, eye)