患者男,44岁。8个月前右臀部出现一板栗大小无痛性肿块,逐渐增大,近6个月来肿块增大迅速,伴持续性剧痛,并逐渐出现右下肢活动障碍,麻木,小便失禁,大便费力,消瘦,无力等症状。入院时查体:右臀部外上象限见一大小约3.0cm×2.0cm×2.0cm的肿块突出皮肤,明显触痛,右臀部可扪及一巨 Male patient, 44 years old. Eight months ago, a chestnut-sized, painless mass appeared on the right buttocks and gradually increased. In the past 6 months, the mass increased rapidly with persistent severe pain and progressive movement problems of the lower extremities, numbness, incontinence, stool effort , Weight loss, weakness and other symptoms. Admission examination: the right hip outside the upper quadrant to see a size of about 3.0cm × 2.0cm × 2.0cm mass prominent skin, obvious tenderness, palpable right hip and a huge