Primitive neuroectodermal (neuroepithelial) tumour of soft tissue of the neck in a child: demonstration of neuronal and neuroglial differentiation.

A 4-year-old girl had a pathologically proven primitive neuroectodermal (neuroepithelial) tumour of soft tissue in the left posterolateral aspect of the neck. The neoplasm consisted of primitive neuroepithelial cells forming Homer Wright rosettes, mature ganglion cells and astrocytes. Astroglia were identified by localization of cytoplasmic glial fibrillary acidic protein (GFAP). Striking similarity is noted between the current tumour and those found in the central nervous system, including cerebellar medulloblastomas. The diverse cellular elements of the present primitive neuroectodermal neoplasm suggest an origin of the tumour from the neuroectodermal component of an ectomesenchymal remnant of the neural crest. Differentiation of the neuroectodermal component of the neural crest into primitive neuroepithelial cells could result in the occurrence of a primitive neuroectodermal neoplasm which may further differentiate into neurons and neuroglia.