Simultaneous occurrence of melanotic neuroectodermal tumor and brain heterotopia in the oropharynx.

A case is described of heterotopic brain tissue with simultaneous occurrence of melanotic neuroectodermal tumor in the oropharynx of a 6-week-old infant. The melanotic neuroectodermal tumor was embedded within the heterotopic glial tissue. This coexistence leads us to speculate that a defect causing a pinching-off of both neural crest cap and medullary epithelium of neural tube might have taken place at, or before, the 25-30 somite stage. The displaced embryonic structures subsequently differentiated into glial tissue, choroid plexus, and melanotic neuroectodermal tumor. This observation may be interpreted as further support in favor of a neural crest origin of juvenile melanotic neuroectodermal tumor.