Scanning electron microscopy as a diagnostic procedure in giant cell arteritis.

Forty-five consecutive patients (32 women and 13 men) underwent biopsy of the temporal artery because of suspected giant cell arteritis. Their ages ranged from 38 to 84 years, mean 68.1 years. Five patients (11.1%) four of them women, were found to be affected by the disease. Their ages ranged from 54 to 80 years, mean 69 years. Clinical and laboratory findings included elevated erythrocyte sedimentation rate, prolonged fever, continuous headache, sudden onset of unilateral blindness, intermittent mandibular claudication, severe anemia and myalgia. None of these, whether present in isolation or in various combinations, were of significant diagnostic value. All biopsies were examined both by light microscopy and by scanning electron microscopy. The former examination took about 5-7 days to complete, and the latter about 3 hours. Light microscopy studies showed that 46.6% of the arterial biopsies were normal, 42.3% were arteriosclerotic and 11.1% (5 specimens) were characteristic of giant cell arteritis. Scanning electron microscopy revealed that the biopsies obtained from all five patients found to have temporal arteritis displayed the "occlusive" pattern: the three-laminar appearance of the artery was markedly distorted or lost, the internal elastic lamina was barely detectable, and the densely hypertrophied media and intima filled the arterial lumen, virtually obliterating it. We conclude that scanning electron microscopy is a quick and accurate procedure for diagnosis of temporal arteritis and that positive findings may be taken as an indication for immediate steroid treatment.