Temporal artery biopsy
Temporal artery biopsies are undertaken for the investigation of temporal arteritis. Although often known as giant cell arteritis1-3, giant cells are not always identified and the temporal artery may be involved by other types of arteritis. To ensure a diagnostic yield, temporal artery biopsies are recommended to be at least 10mm in length.2
Record the patient identifying information and any clinical information supplied together with the specimen description as designated on the container. See overview page for more detail on identification principles.
- Non-routine fixation (not formalin), describe.
- Special studies required, describe.
- Ensure samples are taken prior to fixation.
See general information for more detail on specimen handling procedures.
Inspect the specimen and dictate a macroscopic description.
Describe the following features of the specimen:
Record as stated by the clinican
- Temporal artery biopsy
- Other, specify
- Total specimen size, in two dimensions, length x diameter1-3
- Torsion, describe if present1
The specimen may be sectioned transversely at a maximum of 5mm intervals1,3. Some centres prefer to section at 3mm intervals to ensure thorough examination of the tissue. If preferred, the biopsy may left intact for processing and dissected prior to embedding to allow for easier orientation in the wax block.1,3 After the intact artery has been processed, embedding staff (i.e. histotechnologist/scientist) must then section the artery in the transverse plane at 1-2mm intervals.3
It is important that all tissue is processed.
Transfer all tissue directly into cassettes and submit for processing. If processed intact, instructions must be communicated to embedding staff for the specimen to be dissected prior to embedding (as outlined above). Segments of artery must be embedded cut end down in the block.1-3 Lens paper, biopsy pads or similar are required to prevent loss of tissue during processing.2,3
Standard protocols for microtomy and special stains for temporal artery specimens should be established. Care should be taken to conserve tissue in case ancillary studies are required.
One approach would be to produce six levels in the first instance followed by further levels as required. Note that it is essential that further levels are taken if inflammation is limited to the adventitia in the initial sections. Further levels are also required to where fibrointimal hyperplasia is evident without inflammation4 if this is the only change present.
- Ribbons with eight sections per slide
- For each 1mm cross-section of artery, five levels3
- Additional levels as requested after initial microscopy; in particular if inflammation is limited to the adventitia3 or fibrointimal hyperplasia without inflammation is the only change present3
- Haematoxylin and Eosin (H&E) staining may be sufficient but Elastic Verhoeff Van Gieson (EVG) is often usedl to identify that the specimen is from an artery and to demonstrate reduplication or internal breaks of the internal elastic lamina1,3
- Immunohistochemistry (e.g. CD68 and CD3 for inflammation of the arterial wall) and amyloid staining on request3
See the reference provided (Recommendations for processing cardiovascular surgical pathology specimens)3 for more detail on sectioning and special stains.
Record details of each cassette.
An illustrated block key similar to the one provided may be useful.
Prof Tony Thomas for his contribution in reviewing and editing this protocol.
Block allocation key
No. of pieces
Temporal artery intact, to be dissected transversely after processing
Lester SC. Blood vessels. In: Manual of Surgical Pathology, Saunders Elsevier, Philadelphia, 2010;306.
Stone JR, Basso C, Baandrup UT, Bruneval P, et al. Recommendations for processing cardiovascular surgical pathology specimens: a consensus statement from the Standards and Definitions Committee of the Society for Cardiovascular Pathology and the Association for European Cardiovascular Pathology. Cardiovasc Pathol. 2012;21(1):2-16