Utility of the SCVP consensus statement of temporal artery biopsy for arteritis

The Society for Cardiovascular Pathology (SCVP) recently released a consensus statement on diagnosing and reporting temporal artery biopsies (TAB). The document addresses diagnostic challenges such as adventitial inflammation, absence of giant cells, and non-arteritis changes. It recommends a three-tiered diagnostic scheme and emphasizes recognizing other types of vasculitis although giant cell arteritis (GCA) is the most common type. In this study, we retrospectively reviewed archival TABs to evaluate the utility of this new statement.

We identified all TABs from our files from 1/2022-12/2023. Slides were blindly reviewed without knowing the original diagnoses. Cases were categorized as active arteritis, no arteritis, or healed arterial injury per the consensus document. Active arteritis cases were further classified as GCA or non-GCA, and the presence of giant cells was noted. Results were compared with the original diagnoses to assess the diagnostic and reporting utility of the SCVP schema.

We included 105 TABs from 102 patients (66 female, 36 male; ages 45-93 years; mean age 71 ± 10 years). Using the consensus guidelines, 12 cases were diagnosed as active arteritis. Notably, 8 of 12 cases did not display giant cells in the media, and 1 case showed an exuberant number of eosinophils, suggesting that non-GCA arteritis should be considered. These 12 cases plus another 2 were originally diagnosed as GCA; the latter 2 cases were reclassified as no arteritis, with a comment noting adventitial-only inflammation. Two additional cases were classified as no arteritis, with original descriptive diagnosis of chronic inflammation in only adventitia. The remaining 89 cases were diagnosed as no arteritis, consistent with the original diagnosis. We did not find any case of healed arterial injury. The most common non-arteritis findings were neointimal hyperplasia and internal elastic lamina calcifications, consistent with age-related changes.

The new SCVP TAB consensus schema can be easily implemented in routine clinical practice. It is also helpful in formulating diagnoses for challenging cases, such as those with adventitial-only inflammation or non-GCA arteritis. Additionally, it provides a unified and consistent reporting scheme.