The diagnosis of giant cell arteritis (GCA) is confirmed by finding
characteristic histological changes in the disease in an arterial segment,
such as the superficial temporal artery. The length of the arterial specimen
is crucial because of the presence of "skip lesions"1
(areas of no inflammation) in GCA. Recently, there has been discussion concerning
the required length of an arterial specimen to securely confirm or exclude
the diagnosis of GCA.2,3
It is generally accepted that 20 mm is an adequate specimen length for a unilateral
biopsy. In a "Letter to the Editor" in the Journal of the
American Medical Association, the issue has been raised as to whether
this is a prefixation or postfixation measurement guideline and whether formalin
fixation reduces the effective length of a temporal artery biopsy specimen.4 This is a potentially important question since
the accuracy of the histological diagnosis of GCA is believed to be strongly
correlated to the length of the fixed artery specimen that is available for
pathological assessment. We report the first available data that directly
address this question.