Tactile-like structures in neurofibromas. An ultrastructural study.

The light- and electron-microscopic features of four neurofibromas are described. In each case, whorled structures resembling tactile corpuscles were observed. Ultrastructurally, these lamellated formations were composed predominantly of perineurial cells, although many had a "central core" containing either a myelinated or unmyelinated axon, or several Schwann cells unassociated with axons. Our findings provide further evidence for the participation of perineurial cells as well as Schwann cells in the histogenesis of neurofibromas.