摘要
the authors report the case of a 52 year-old woman that presented macroscopic hematuria and pelvic pain. ultrasound examination was performed, which showed an expansive mass in the bladder floor. a cystoscopy confirmed the presence of this lesion and a biopsy was carried out. histological analysis showed a small cell neoplasm. the immunohistochemical analysis was required to establish diagnosis. this analysis revealed positivity for ews-fli1, cd99 and s-100. the conclusive diagnosis was primitive neuroectodermal tumor. the patient was treated with chemotherapy. after a seven month follow-up period, the patient is disease-free.