PERIPHERAL PRIMITIVE NEUROECTODERMAL TUMOR INVOLVING THE PARAVERTEBRAL AND RETROPERITONEAL REGIONS

A rare case of peripheral primitive neuroectodermal tumor (PNET) is re ported. A 68-year-old woman complaining of lumbago was admitted to our hospital, Diagnosis was made based on pathological findings character ized by Homer Wright-type rosettes, Ultrastructural examination showed the presence of neurosecretory granules and short cytoplasmic process es, which were highly suggestive of neural differentiation. Chromosoma l analysis of the neoplastic cells revealed translocation (11;22)(q24; q12), which is often found in Ewing's sarcoma and Askin tumor, These r esults strengthen the hypothesis of a common histogenesis for these sm all round cell tumors, and suggest common oncogenesis for these neopla sms.