Primitive neuroectodermal kidney tumor

To the Editor: Primitive neuroectodermal tumors (PNET) and Ewing sarcoma (ES) belong to a group of neoplasms de®ned by neuroectodermal differentiation and a characteristic cytogenetic translocation, t(11;22) (q24;q12) or gene rearrangements between chromosomes 21 and 22 [1]. They are generally aggressive tumors that present as metastatic disease in nearly 50% of the cases. ES is frequently a bone disease, whereas PNET can occur in bones, soft tissues, or any other site. Renal PNETs are extremely rare, with only a few cases reported [2]. We here record an adult with renal PNET and bone metastases at diagnosis. Because these tumor can also be found in children [3] our experience may therefore…