Bladder extragastrointestinal stromal tumor in an adolescent patient: A case-based review.

Extragastrointestinal stromal tumors (EGISTs) are mesenchymal tumors occurring outside the gastrointestinal tract, with histological, immunohistochemical and molecular genetic characteristics similar to those of gastrointestinal stromal tumors (GISTs). The immunohistochemical examination usually demonstrates a positive expression for CD117. GISTs are rare neoplasms and EGISTs are even less common. This is the report of a case of EGIST in the urinary bladder of a 15-year-old adolescent female patient who presented with painless gross hematuria. Pelvic computed tomography revealed an irregular soft tissue density mass, sized 5.7×4.8 cm, in the bladder. Partial cystectomy was performed in April, 2011. There was no recurrence during follow-up over the next 35 months, as determined by transabdoninal ultrasonography and cystoscopic examination. The patient in this study did not receive any molecular-targeted drugs. To the best of our knowledge, this is the first reported case of an EGIST of the urinary bladder in an adolescent patient.