From the Journals

Frozen sections can guide biopsies for giant cell arteritis, but are they feasible?



Positive findings from frozen sections of a first temporal artery biopsy can effectively identify giant cell arteritis, ruling out in those cases the need to perform a second biopsy on the contralateral side and arguing against the use of simultaneous bilateral biopsies, according to results from a retrospective study of nearly 800 patients who underwent the procedure at the Mayo Clinic during 2010-2018.

A micrograph of giant cell arteritis with hematoxylin and eosin staining. Nephron/Wikimedia Commons

A micrograph of giant cell arteritis with hematoxylin and eosin staining.

Although temporal artery biopsy (TAB) remains the standard diagnostic test for giant cell arteritis (GCA), second TAB procedures are often performed in patients with a high level of suspicion for GCA, which may result in unnecessary treatments and complications, Devon A. Cohen, MD, of the Mayo Clinic, Rochester, Minn., and colleagues wrote. (Dr. Cohen is now a clinical fellow in ophthalmology at the Massachusetts Eye and Ear Infirmary.)

At the Mayo Clinic, TAB specimens are first examined with frozen sections at the time of the biopsy; this process, followed within days by formalin-fixed tissue permanent sections, is unique to Mayo. “A frozen section–guided sequential TAB is commonly performed, with the results of the first biopsy obtained within minutes, which determines the need for evaluation of the contralateral side,” the researchers said. However, the use of frozen sections to evaluate patients with GCA has not been well studied.

In a retrospective cohort study published in JAMA Ophthalmology, the researchers identified TAB patients aged 40 years and older who underwent TAB procedures between Jan. 1, 2010, and Dec. 1, 2018, at the Mayo Clinic. The average age of the patients was 72 years, and 41% were men.

Strong positive predictions from frozen sections

The researchers analyzed 1,162 TABs from 795 patients using frozen and permanent histologic sections.

Overall, 119 patients (15.0%) and 138 TABs had positive permanent section findings, and 103 (86.6%) of these patients also had positive frozen section findings, including 4 false positives and 20 false negatives. The frozen section specificity and sensitivity was 99.4% and 83.2%, respectively, for detecting inflammation suggestive of GCA, and the positive and negative predictive values were 96.1% and 96.6%, respectively. Positive and negative likelihood ratios for frozen section were 140.6 and 0.17, respectively.

In a multivariate analysis, the odds of a positive permanent section TAB significantly increased with age (odds ratio, 1.04), vision loss (OR, 2.72), diplopia (OR, 3.33), headache (OR, 2.32), weight loss (OR, 2.37), and anorexia (OR, 5.65).

A total of 60 patients underwent bilateral TABs, and 307 patients underwent bilateral frozen section–guided sequential TABs; the discordance rates based on permanent sections were 5.0% and 5.5%, respectively.

Those discordance rates are “an important result applying to everyone working with patients suspected for GCA,” Patricia Chévez-Barrios, MD, of Houston Methodist Hospital, wrote in an accompanying editorial. “This is on the low end of what was previously published (3%-40%) and supports the relative low need for bilateral synchronous TAB for the diagnosis of GCA.”

A key issue in GCA diagnosis is the need to confirm inflammation, Dr. Chévez-Barrios said. “The surgeon must obtain a significant portion of the artery, and the pathologist should review several sections and levels of the tissue to confidently say whether there is inflammation or no.”


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