Urothelial tumors of the urinary bladder in young patients: a clinicopathologic study of 59 cases.

CONTEXT: Urothelial tumors are rare in young patients. Because of their rarity, the natural history of the disease in young patients remains poorly understood.
OBJECTIVE: To understand the pathologic and clinical features of urothelial tumors of the urinary bladder in young patients.
DESIGN: We identified 59 young patients with urothelial tumors of the urinary bladder treated at our institution and analyzed the tumors' pathologic features and the patients' clinical outcomes.
RESULTS: All patients were 30 years or younger, with a mean age of 23.5 years (range, 4-30). Thirty-eight patients (64%) were male, and 21 (36%) were female. Most tumors were noninvasive, papillary urothelial tumors (49 of 59; 83%), including papillary urothelial neoplasms of low malignant potential (7 of 49; 14%), low-grade papillary urothelial carcinomas (38 of 49; 78%), and high-grade papillary urothelial carcinomas (4 of 49; 8%). Only a few (n=10) of the urothelial tumors were invasive, invading the lamina propria (n=5; 50%), muscularis propria (n=4; 40%), or perivesical soft tissue (n=1; 10%). Clinical follow-up information was available for 41 patients (69%), with a mean follow-up time of 77 months. Of 31 patients with noninvasive papillary urothelial tumors, only 1 patient (3%) later developed an invasive urothelial carcinoma and died of the disease, and 30 of these patients (97%) were alive at the end of follow-up, although 10 (32%) had local tumor recurrences. In the 10 patients with invasive urothelial carcinomas, 3 patients (30%) died of the disease and 5 others (50%) were alive with metastases (the other 2 [20%] were alive with no recurrence).
CONCLUSION: Urothelial tumors in young patients are mostly noninvasive, papillary carcinomas and have an excellent prognosis; however, a small subset of patients may present with high-grade invasive urothelial carcinomas that result in poor clinical outcomes.