Abstract
1. Three solitary tumours of the peripheral nerve trunks are reported. None of the patients showed evidence of von Recklinghausen's disease.
2. The origin of these tumours is discussed; the evidence suggests that they develop from the Schwann cells of the nerve sheaths, and they should therefore be called neurilemmomas.
3. A solitary tumour of a peripheral nerve trunk is usually a neurilemmoma and not a neurofibroma.
4. These tumours are often mistaken for neurofibromas, from which they are wholly distinct. They are uncommon, but probably occur more often than is generally appreciated.
5. A neurilemmoma is a benign tumour which can be distinguished from a neurofibroma on clinical and operative grounds. It must be enucleated with preservation of its parent nerve. There is negligible risk of recurrence and no risk of malignant change after operation.
6. Neurilemmomas are liable to cystic degeneration, especially in situations where they are subjected to pressure or injury. This cystic change may later destroy the usual cellular structure of the tumour and convert it into a simple cyst.
