患者，男，６２岁，主因左上、下肢斑块、结节等一年，加重一月，于１９９７年１２月９日入院。一年前，无明显诱因左前臂伸侧起一红色丘疹，搔抓后迅速增大，形成潮红、坚韧无疼的结节，并逐渐增大，三月后已形成拳头大斑块，中心坏死、溃疡，上覆黑色厚痂，挤压痂皮后有少量 Patients, male, 62 years old, mainly due to the left upper and lower limbs plaque, nodules and other year, increased in January, was admitted on December 9, 1997. A year ago, there was no obvious incentive to extend the left forearm extensor from a red papule, rapidly increasing after scratching, resulting in a flushed, tough and painless nodule, and gradually increased after March has formed a fist big plaque, central necrosis , Ulcers, overlying black thick crust, squeeze a small amount after the crust