Melanotic neuroectodermal tumor of infancy with high serum levels of alpha-fetoprotein. Ultrastructural study and immunological evidence of glial fibrillary protein and alpha-fetoprotein.

We report an infant melanotic neuroectodermal tumor in the anterior part of the upper gingiva, which was associated with high urinary excretion of vanilmandelic acid. Serum levels of alpha-fetoprotein were abnormally high (200 ng/ml). They returned to normal after removal of the tumor (10 ng/ml). The tumor was characterized histologically and ultrastructurally by the presence of melanocytic and astrocytic cells containing glial fibrillary protein. Intracellular alpha-fetoprotein was demonstrated by the immunoperoxidase method (PAP) in scattered foci of interstitial cells.