Objective: Urothelial bladder tumours are rare before the age of 40 and represent only 1% to 4% of all bladder tumours. This study reviews the histological features of these tumours and tries to more clearly define their natural history.
Material and method: From 1980 to 2000, we observed 2,600 cases of primary bladder tumours; 34 subjects were younger than 40. We studied the course of 26 subjects with a urothelial tumour. Their mean age was 30 years (range: 16 to 40 years) and 8 patients were younger than 30.
Results: 22 of the 26 patients presented a superficial tumour, including 21 cases of stage Ta tumour. The majority of tumours were well differentiated. Two patients had a multifocal tumour and 4 patients had a tumour larger than 3 cm in diameter. The overall recurrence rate was 55% with progression of the tumour stage in 9% of cases. A better prognosis was observed before the age of 30, with a recurrence rate of 38% versus 62% in patients between the age of 30 and 40. Four patients had an invasive tumour, which was metastatic at the time of diagnosis in 3 cases.
Conclusion: The natural history of superficial bladder tumours appears to differ according to age. Before the age of 30 years, tumours are frequently stage Ta, well differentiated, with a low recurrence rate. Between the ages of 30 and 40 years, the course of superficial bladder tumours is similar to that observed in older subjects. However, the prognosis of invasive tumours is usually very poor, indicating a particularly aggressive potential.