[Penetrating hyperkeratosis of an amputated limb]

On the stump of amputated limbs, a peculiar hyperkeratotic chronic lesion may be observed. The histological picture of this lesion shows a hyperkeratotic plug perforating the epidermis. In the dermis disorganised keratine lamelles are found. This lesion could be differenciated from Kyrle's disease by the fact that it consists of a single lesion of traumatic origin and by the presence of hypertrophic bundles underlying the hyperkeratosis.