Polysialic acid as a marker of both immature and mature neural tissue in human teratomas.

The neural cell adhesion molecule (NCAM) is involved in cell-cell interaction during neural development. We employed a monoclonal antibody directed against the long chain polysialic acid moiety of NCAM to evaluate its usefulness as a marker of primitive neural elements in teratomas. This marker was compared with other neural markers, S-100, glial fibrillary acidic protein (GFAP), neurofilament protein (NFL), nerve growth factor receptor (NGFR), as to its effectiveness in labeled neural tissue in human teratomas. The anti-polysialic acid antibody was the only reagent that consistently marked all types of neural tissue, both mature and immature in these lesions. Immature neural elements alone have prognostic significance in teratomas. Our results indicate that anti-polysialic acid antibodies are the most sensitive and useful markers of immature neural elements in these lesions.