Banded structures in cauda equina.

Banded structures identified in a cauda equina biopsy from a patient with compression are identical to those seen in schwannomas and several other conditions and identified as fibrous long-spacing collagen. They are present in relation to the basement membrane with a periodicity of about 1200 A. It was not possible to identify their substructure further. It is postulated that the initiating factor in their formation in this instance is compression of the spinal nerves.