title: Peripheral primitive neuroectodermal tumor of the urinary bladder in an Arab woman with history of squamous cell carcinoma: a case report.
abstract: BACKGROUND
  Peripheral primitive neuroectodermal tumors of the urinary bladder are rare and tend to occur in an older age group than do their counterparts in bones and soft tissue.
  
  
  METHODS
  We report a case of peripheral primitive neuroectodermal tumor of the urinary bladder in a 67-year-old woman of Arab origin. She had undergone transurethral resection followed by chemotherapy because of pulmonary metastasized muscle-invasive squamous cell carcinoma of the bladder in 2005. One year later, she first presented with a history of repeated hematuria in our institution. Performing cystoscopy any tumor could be detected. Control cystoscopy two months later showed a tumor mass of 3 cm in diameter at another location than described for the first tumor. After perforating by transurethral resection partial bladder resection had to be done. Tissue specimen after pathological analysis revealed a peripheral primitive neuroectodermal tumor with tumor cells reactive to cluster of differentiation 99, neuron-specific enolase and S100 protein and stained negative for other markers such as cytokeratins, epithelial membrane antigen, desmin, smooth muscle actin, chromogranin and leucocyte common antigen. Staging computerized tomography was especially free from any hint on organ metastasis, but the patient died due to a cardiac problem only a few months later.
  
  
  CONCLUSIONS
  To the best of our knowledge, we report the eighth case of bladder peripheral primitive neuroectodermal tumors in literature and the first concerning an Arab patient. It is also the first presentation of a peripheral primitive neuroectodermal tumor patient with a history of squamous cell carcinoma of the bladder. As in other cases, expression of single-chain-type 1 glycoprotein and neural markers was positive and the disease was at an advanced stage at the time of diagnosis.
authors.forename: Mohd Khaled
authors.initials: MK
authors.lastname: Al Meshaan
authors.forename: Marwan
authors.initials: M
authors.lastname: Nayef
authors.forename: Talal
authors.initials: T
authors.lastname: Kwaider
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Otto
authors.forename: Ken C
authors.initials: KC
authors.lastname: Katchy