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Normal TA. intima. media. adventitia. Bluish curly line is internal elastic lamina. intima. media. Elastin Von Gieson (EVG) stained internal elastic lamina-normal. adventitia. media. INTIMA. MEDIA. EVG STAIN. Temporal arteritis. Temporal arteritis.
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intima media adventitia
Bluish curly line is internal elastic lamina
intima media Elastin Von Gieson (EVG) stained internal elastic lamina-normal.
adventitia media
INTIMA MEDIA
Temporal arteritis • Idiopathic, granulomatous vasculitis of large or medium sized elastic arteries. SKIP LESIONS • Predilection for superficial temporal artery, but can affect cerebral arteries, carotids, coronary arteries, aorta, renal arteries etc… • Pathogenesis-actinically damaged elastic tissue-trigger cell-mediated immune response ? Infection? • Histology-with and without giant cells. Adventitial acute and chronic inflammation with involvement of media (muscle layer). Fragmentation of internal elastic lamina. • Giant cells at sites of internal elastic lamina rupture (not always). • Inflammatory oedema of intima, with stenosis of lumen.
American College of Rheumatology Criteria • Based on the 1990 American College of Rheumatology criteria for classification of giant cell arteritis, 3 of the following 5 items must be present: • Development of symptoms in patients older than 50 years • New onset of headache or localized head pain • Temporal artery tenderness to palpation • Decreased pulsations not related to arteriosclerosis of cervical arteries • ESR greater than 50 mm/h
Temporal artery biopsy • No evidence base for how long biopsy should be. The longer the better as maximises chances of catching skip lesion. • Target biopsy to painful segment-important. • During handling in pathology lab- serial sections are cut through the entire specimen (with or without elastin stains), to increase chance of picking up skip lesion.
Temporal artery biopsy • Minimum distance between skip lesions =350 microns (autopsy data). • Positive biopsy rate in pre-steroid cases 30-70 % of cases (depending on which papers read) (usually 60-70%). • Positive biopsy rate after week of steroids-20%-probably due to decreased sampling efficiency as pain is reduced. • Can detect trans-mural scarring in healed arteritis. Seeing scarring is not an indication to stop steroids.
Why biopsy ? • Biopsy often done for medicolegal reasons to confirm diagnosis. Helpful when positive. • Steroid treatment is not an easy undertaking....numerous side effects. Therefore positive biopsy justifies continued treatment.