Treatment of uncommon malignant tumours of the bladder

Urothelial carcinoma is the most common histological type of bladder tumours. Nevertheless, its variants and less common types represent 20% of all bladder cancers. The objective was to update the recent publications on these rare diseases and to draw conclusions for clinical management.

Recent retrospective studies have been published. They refine the description of histological patterns and of immunochemistry diagnosis. Taking into account the heterogeneity of these pathologies, several groups have benefited of increased knowledge such as sarcomas and lymphomas. The need of international collaboration to study prospectively some subgroups of tumours is crucial.

Rare bladder cancers have generally poor outcome and in a majority of the cases surgery, namely cystectomy remains the most important curative treatment. Specific subgroups, as lymphoma, sarcoma and dedifferentiated epithelial tumours may benefit of molecular characterization and trials with targeted drugs.