A survey of cutaneous neural lesions for the presence of myelin basic protein. An immunohistochemical study.

The presence of myelin basic protein (MBP) within a skin neoplasm would support its derivation from Schwann's cells, since this substance is routinely present within Schwann's cells in the peripheral nervous system. Using a monoclonal antibody prepared against MBP and an unlabeled antibody peroxidase-antiperoxidase assay, we surveyed a variety of skin lesions suspected of being derived from Schwann's cells to determine whether MBP was present. Myelin basic protein was detected within the cytoplasm of cells composing benign solitary schwannoma (neurilemmoma) and neurofibroma, confirming the association of these lesions with proliferation of Schwann's cells. Myelin basic protein was not found in a variety of intradermal and compound nevus cell nevi nor in malignant melanoma. This negative finding supports electron microscopic evidence suggesting that nevus cells have no relationship to Schwann's cells even though some nevus cell arrangements suggest Schwann's cell derivation under the light microscope.