BIOPSY IN SYSTEMIC VASCULITIDES - GUIDELI NES AND PITFALLS

Biopsy examinations may be of great importance for the diagnosis of sy stemic vasculitides if they are correctly performed and some general p itfalls are avoided. Apart from technical mistakes (insufficient or to o superficially excised material, necrotic tissue material without int act border areas, bad or retarded fixation), the following points shou ld be kept in mind: Immunohistochemical and electron microscopic exami nations are practically worthless for diagnostic reasons. The surgical access to the biopsy area and the tolerability of the intervention sh ould be carefully evaluated. Biopsies without sufficient information t o the pathologist about the clinical findings and the laboratory resul ts are often responsible for insufficient pathology reports. Biopsies during or immediately after a corticosteroid treatment provide faulty results. Skin biopsies in systemic vasculitides usually present non-sp ecific alterations. Polymyalgia does not cause a temporal arteritis an d no conclusive findings within the striated musculature. A <<blind>> temporal artery biopsy has only a limited chance to provide findings o f diagnostic value. The sites which offer the best possibilities for b iopsy in various systemic vasculitides are enumerated and the possible histology findings at these sites are discussed.