The individual fiber of a peripheral nerve is composed of an axon or neurite, which is usually encased in a myelin sheath. Surrounding this is a protoplasmic envelope, the sheath of Schwann. These elements, the neurite, the myelin sheath, and sheath of Schwann, are neurogenic in origin (Fig. 1). The neurite is a prolongation of an individual nerve cell, while the sheath of Schwann is composed of a syncytium of cells which migrate out from the neural crest in early embryonic life (Harrison). The myelin sheath is supposedly a product of the nerve cell. The individual nerve fibers are embedded in connective tissue, the endoneurium, and are gathered into bundles enclosed by fibrous tissue, the perineurium. The entire nerve, consisting of these bundles of individual fibers, is overlaid by connective tissue, referred to as epineurium (Fig. 2). Tumors of the peripheral nerves were divided by Virchow, in 1863, into false neuromas, which include tumors of the nerve sheath, and true neuromas including growths arising from nerve fibers or nerve cells. Among the true neuromas are ganglioneuromas of the peripheral, spinal, and sympathetic nerves, and amputation neuromas, which are a combination of nerve fiber and sheath regeneration following the severing of a nerve trunk. Sporadic examples of neuro-epitheliomas of the peripheral nerves have been reported.