Below armour outside crude character wart is tumour of a kind of benign bone, happen at toe, can cause the change of toenail and the pathological changes that fallibility examine is toenail.

• 甲下外生骨疣是一种良性骨肿瘤,发生于足趾时,可以引起趾甲的改变而易误诊为趾甲的病变。