巨细胞动脉炎（颞动脉）在50岁以前较少见。血沉速率常常明显地升高（可达100 mm/hr甚至更高）。半数以上的病人有风湿性多肌痛。高倍镜下可见病灶的肉芽肿炎症伴有动脉腔狭窄。
Giant cell (temporal) arteritis is uncommon before age 50. The sedimentation rate is often markedly elevated (100 mm/hr or more). Half of patients have polymyalgia rheumatica. The focal granulomatous inflammation with narrowed arterial lumen is seen here at high magnification.