[Histopathologic and ultrastructural study of various amputation neuromas].

The results of a light and electron microscopy study of seven amputation neuromas are presented. The neuromas were removed during surgery for traumatic lesions of limbs. The histological study showed a complete disappearance of the nerve architecture at the neuroma level, where the fibres are collected in small bundles, enveloped in an abnormal perineural sheath, surrounded by an overgrowing connective tissue. In two cases a partial and incomplete reinnervation of the distal stump was found. The ultrastructural study shows abnormalities of the nervous fibers, both of the axon and of the relationships between the axonal part and the Schwann cell. The results of our data in man are compared to nerve regeneration patterns recently investigated in experimental models.