Abstract
A small cell round tumor involving the chest wall of a 19-year-old female had features that by light microscopy were considered consistent with Ewing's tumor. At the ultrastructural level the cells contained small quantities of glycogen and had irregular dendritic processes with rare dense core granules and microtubules. Immunostaining for neuron-specific enolase was positive. The neoplasm is similar to reported cases of peripheral neuroectodermal tumor involving the chest wall of young patients.